Imagined in the 1950s

A large prize. Building from local rock would sharply cut the cost of any base on the Moon.

Who is paid. A government is assumed to pay for lunar bases, and the method can be copied, so the contractors already building there collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A lift from the ground to orbit would slash the cost of reaching space for every firm that uses it.

Who is paid. Shippers pay to send cargo up, and since another line could be built once the first was shown to work, the gain is assumed to go to the large builders and the holders of the few good ground sites.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Flinging or pushing payloads to space without big rockets would change the cost of the whole launch industry.

Who is paid. Firms with cargo to launch pay, and since others could build such works the gain goes to those who already own launch sites and power.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A working ship that carries people and cargo between worlds is the base of a whole transport industry.

Who is paid. Carriers and other firms working in space buy ships, and since a second yard could build the same craft the established shipbuilders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A working vessel for travel between worlds would found a transport industry of its own.

Who is paid. Carriers and expedition firms buy ships, and many yards could build them once shown how, so established vehicle builders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. The nozzle stands here for the nuclear rocket it belongs to, an engine that would set how far and fast ships can go.

Who is paid. Whoever runs the ship pays for the engine, assumed here to be carriers, and once a firm had built it others could too, so established engine and ship builders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Water and air made on the Moon would spare hauling them from Earth, lowering costs for everything based there.

Who is paid. Firms working on the Moon buy the water and air, and baking rock is a method any miner could copy, so the operators that already hold the sites and plant collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A shelter that goes up quickly serves small parties on airless ground, a niche.

Who is paid. No user is named, so it is assumed that firms working on other worlds buy it as working gear, and a shelter that must hold air against vacuum is made by the established makers of suits and habitats, any of whom could copy it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. It lets a settler family grow food on an airless rock, a niche for the few who homestead there.

Who is paid. Settlers are assumed to buy it for themselves, and a shelter that must hold air against vacuum is made by the established makers of suits and habitats, any of whom could copy it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Training for would-be settlers is a niche service for the few who go.

Who is paid. Settlers pay their own fees, assumed here, and anyone with the knowledge can open a school, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A working ship that carries people and cargo between worlds is the base of a whole transport industry.

Who is paid. The story's craft belongs to invaders, but judged as a ship it is assumed carriers would buy it, and a second yard could build the same craft so established shipbuilders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Thickening thin air until a person can breathe it is a useful piece of kit for the few who work on such worlds.

Who is paid. Ship and expedition operators pay for it with their other gear, and the established builders of ships and suits supply it because the method is easy to copy.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A reusable craft flying between the ground and a station is the working vessel of a transport industry of its own; the real thing flew but cost far more than the promise.

Who is paid. Carriers and expedition firms buy ships, and many yards could build them once shown how, so established vehicle builders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. An outpost built up piece by piece for people to live and work in orbit is a building industry of its own.

Who is paid. A station is a public work a government pays for, and the big construction and space firms that already win such contracts would build it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A waypoint where travellers change ships is needed by the traffic it serves, but the prize lies in the transport and the port is a part of it.

Who is paid. Unlike other stations this is a port, so the carriers that call there are assumed to pay to use it as they would a spaceport, and since such a port can be copied the large builders and port owners collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Spinning to give weight is a design feature of a station, useful but not a product of its own.

Who is paid. Whoever pays for the station pays for this, assumed here to be a government, and any station builder can use the idea so the established builders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A warm dry shelter is a local comfort for settlers on a rain-soaked world.

Who is paid. The shelters are assumed to be public refuges open to any settler, so a government pays, and ordinary building firms supply them.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A world covered from end to end by city is a settlement at the largest scale, an enormous building project.

Who is paid. Residents and shopkeepers each pay for their own space in open air, as in any city, and the developers, builders and landowners already there collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Fast flight between distant cities by way of space would change long-distance travel.

Who is paid. Airlines and carriers buy the craft, and once it flew other builders could copy it, so established craft builders and carriers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A pocket finder for lost tools is a small convenience for orbital workers.

Who is paid. Space operators buy it for crews, and it is ordinary electronics that many firms could make.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. It helps a spacewalker get around while weightless, a niche tool for a few workers.

Who is paid. Space operators buy it for their crews, and the makers of suits and space gear supply it because it is easy to copy.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A suit that keeps a person alive in vacuum is vital to its wearer but serves only the few who work in space.

Who is paid. Space operators buy suits for their crews, and the few firms that already make such gear supply them since the design can be copied.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

No prize. It is a natural thing or place in space, not something made or sold.

Who is paid. Nothing is sold, so nobody pays and no seller collects.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A quick patch for a holed hull can save a crew, but it is a cheap spare, a niche.

Who is paid. Space operators buy it for their crews, and it is simple enough that any workshop could make it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Keeping your footing where there is little or no weight is a small convenience for those who work there.

Who is paid. Space operators buy it for their crews, and it is a simple loose item that any workshop could make.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

No prize. It is a word, not a product anyone makes or sells.

Who is paid. Nothing is sold, so nobody pays and no seller collects.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

No prize. It is a kind of planet, a natural thing and not a product anyone makes or sells.

Who is paid. Nothing is sold, so nobody pays and no seller collects.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Forecasts of storms in space are useful to every voyage but a small part of its cost; the forecasters and their map are the same service.

Who is paid. As with the weather map, a forecast serves every ship and is hard to charge for, so a government is assumed to pay, and the forecasting bodies that already hold the watching instruments collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Cheap passenger rockets for holidays would open space travel to ordinary people, a travel industry of its own.

Who is paid. The carrier buys the rocket and holidaymakers buy seats from it, as with a liner, and since the rockets could be copied the builders and carriers that already own fleets and ports collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Keeping a caustic outside air from getting in is essential on such a world but is a fitting of the building or craft.

Who is paid. Ship operators pay for it as part of the craft, and the established builders of ships and stations supply it since the idea is easy to copy.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A squeeze pouch for drinking without weight is a small convenience for crews.

Who is paid. Space operators buy it for crews, and it is simple hardware that many workshops could make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

No prize. It names what space does to the body, a condition and not a product anyone makes or sells.

Who is paid. Nothing is sold, so nobody pays and no seller collects.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A map of the galaxy guides travellers and scholars but is a survey, with little to sell beyond the charts.

Who is paid. As with other sky surveys a government is assumed to pay, and the survey bodies that already hold such contracts would do the work.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Keeping muscles strong in orbit matters to the few who live there, a niche.

Who is paid. Operators buy it for their crews, and unlike the spinning rig it is only straps, which any workshop could make.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. It is a necessary fitting on any crewed craft, but only a part of the ship.

Who is paid. Ship operators pay for it within the craft, and shipbuilders make it themselves since nothing stops others copying it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A thruster that clamps onto any cargo and pushes it to orbit would change the cost of launching goods.

Who is paid. Firms with cargo to launch pay, and since others could build such thrusters the established engine and launch firms collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A ground trainer for pilots is needed by every operator but is a small part of what flying costs.

Who is paid. Ship operators and flight schools buy it, and the firms that already build craft and their controls could all make it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A bare open frame for hauling things nearby is the simplest kind of orbital tug, a support tool.

Who is paid. Port and ship operators buy tugs, and any spacecraft builder could make such a simple craft, so established builders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A way to survive a failing ship is something every operator wants but hopes never to use.

Who is paid. Ship operators buy it as part of the craft, and the established builders of ships and their fittings supply it since it can be copied.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. An engine that quickly reaches almost the speed of light would open other stars to trade and settlement, a transport industry of its own; it is a change for those who go, not for most people.

Who is paid. Ship operators pay for the drive, and once a firm had built it others could too, so established shipbuilders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A hangar for assembling big rockets and station parts is ground equipment for the launch trade.

Who is paid. Builders of rockets and stations pay for it, assumed here, and large construction firms could all put up such a hall.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A ship that can keep up hard thrust for long periods would cut travel times between worlds, a transport industry of its own.

Who is paid. Carriers and expedition firms buy ships, and many yards could build them once shown how, so established vehicle builders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Cups that hold liquid without weight are a small convenience for crews.

Who is paid. Space operators buy it for crews, and it is simple hardware that many workshops could make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A vast prize. Giving a whole world air and a climate people can live in would open new land for a large share of humanity.

Who is paid. Only a government could fund work on a whole world, and the large engineering firms that already hold such contracts would be paid to do it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Daily travel to work on other planets would change where many people can hold jobs.

Who is paid. The carrier buys the ship and workers buy fares from it, as with a liner, and since the ships could be copied the builders and carriers that already own fleets and ports collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. It saves lives in a disaster, but it is safety equipment carried aboard a larger ship.

Who is paid. Ship operators pay for it as required safety gear, and shipbuilders supply it because the design is easy to copy.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A bare capsule for a few travellers or a little cargo is a cheap niche form of space transport.

Who is paid. Carriers or expedition firms would buy it, assumed here, and existing spacecraft builders could all make something so simple.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

No prize. It is an event, crowded routes, not a product; the commuter craft are judged elsewhere.

Who is paid. Nothing is sold, so nobody pays and no seller collects.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

No prize. It is a natural thing or event in space, not a product anyone makes or sells.

Who is paid. Nothing is sold, so nobody pays and no seller collects.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A place for many people to live and work beyond Earth is a building industry of its own.

Who is paid. A settlement is a public work a government pays for, and the big construction and space firms that already win such contracts would build it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Powder as reaction mass is a cheap fuel choice, a minor saving for ship operators.

Who is paid. Ship operators buy it, and ground rock is something anyone can supply, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A ship that carries a whole community for generations is a vast building job, but a rare one.

Who is paid. Only a government could fund a voyage with no return, and the big shipbuilders that already hold public contracts would build it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A place for Moon dwellers to unwind is a local leisure spot, a convenience.

Who is paid. The people living there pay to visit, and the building is easy to copy, so whoever already holds ground and supply lines on the Moon collects.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A place to land, park or refuel is a necessary part of space traffic but only an extra beside the ships and launch works.

Who is paid. Ship operators pay to use it, and it is easy to copy, so those who already hold the port sites collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A rail line across the Moon serves only those who live and work there, a niche.

Who is paid. No owner is named, so it is assumed a carrier buys it like other surface vehicles and sells seats, and established rail builders could all make it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Checking whether air is safe to breathe is a useful instrument for a few explorers.

Who is paid. Expedition firms buy it, assumed here, and gas-testing instruments are made by many firms, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A forward post at the edge of explored space serves scouts and patrols, an outpost and not a town.

Who is paid. Exploring and guarding a frontier is assumed to be a government's work, and the established station builders would be paid.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A ladder for climbing down from a landed ship is plain equipment.

Who is paid. Space operators buy it for crews, and it is simple enough that many workshops could make it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A vehicle for crossing another world serves a few expeditions, a niche.

Who is paid. No user is named, so it is assumed that firms working on other worlds buy it like other working gear, and established vehicle builders could all make it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

No prize. It is a word for a creature from another world, not a technology anyone makes or sells.

Who is paid. Nothing is sold, so nobody pays and no seller collects.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

No prize. It is a natural thing or place in space, not something made or sold.

Who is paid. Nothing is sold, so nobody pays and no seller collects.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A place to land, park or refuel is a necessary part of space traffic but only an extra beside the ships and launch works.

Who is paid. Ship operators pay to use it, and it is easy to copy, so those who already hold the port sites collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

No prize. It is a makeshift refuge pieced together from rock and wrecks, assumed here to be made by castaways for themselves and never bought or sold.

Who is paid. Nothing is sold, so nobody pays and no seller collects.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A beacon marking a settled world is a minor aid to navigation.

Who is paid. A beacon serves all ships and none can be charged, so a government pays, and a simple transmitter is something many firms could build.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A small craft that lands and lifts off again is a ship's own ferry, an extra rather than an industry.

Who is paid. Ship and station operators buy it, assumed here, and existing spacecraft builders could all make something so simple.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. An ordinary rocket to orbit is the plain workhorse of space transport, an industry of its own.

Who is paid. Carriers buy rockets to move people and cargo, and many builders can make an ordinary one, so established builders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Snagging cargo off a planet from a passing craft would be a new and cheaper way to lift goods to space.

Who is paid. Shippers pay to send cargo up, and once it was shown to work another line could be flown, so the builders and carriers already in the trade collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A cave for storing air and for flying as a pastime is a local amenity for settlers.

Who is paid. Settlers pay to fly there, assumed here, and whoever already owns the cave collects since such caves are few.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. It helps a crew find their way or see what lies about them, a useful fitting but only a part of the ship.

Who is paid. Ship operators pay for it within the craft, and the firms that already make ship instruments supply it since the design can be copied.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. It helps a crew find their way or see what lies about them, a useful fitting but only a part of the ship.

Who is paid. Ship operators pay for it within the craft, and the firms that already make ship instruments supply it since the design can be copied.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A ship that crosses between stars in an instant is the base of a transport industry, the size settled for faster-than-light travel elsewhere.

Who is paid. Carriers and other firms working in space buy ships, and since a second yard could build the same craft the established shipbuilders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A frame that holds a craft on the ground is a simple port fitting.

Who is paid. Port and ship operators buy it, and it is plain steel that any workshop could make.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A suit that keeps a person alive in vacuum or thin air is vital to its wearer but serves only the few who work in space.

Who is paid. Space operators buy suits for their crews, and the few firms that already make such gear supply them since the design can be copied.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

No prize. It is a word or a way of doing things that needs no new equipment, not a product.

Who is paid. Nothing is sold, so nobody pays and no seller collects.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Working out a safe course between stars is essential to such travel but is an instrument within the ship.

Who is paid. Ship operators buy it as part of the craft, and the established makers of flight instruments supply it since it can be copied.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Metal and other materials from space rocks would be an industry of its own and could change the cost of raw materials.

Who is paid. Factories and builders buy the output, and since mining methods are easy to copy the firms that already own ships and refineries collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A vast prize. A new world to live on would add living room for a large share of humanity.

Who is paid. No private buyer could fund a world, so a government pays and the large builders that already hold public works contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. It is a handy detail of a helmet, a convenience for the few people who wear spacesuits.

Who is paid. Operators pay for it as part of the suit, and suit makers fit it themselves because any of them could copy it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. It is a handy detail of a helmet, a convenience for the few people who wear spacesuits.

Who is paid. Operators pay for it as part of the suit, and suit makers fit it themselves because any of them could copy it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

No prize. It is a natural thing or event in space, not a product anyone makes or sells.

Who is paid. Nothing is sold, so nobody pays and no seller collects.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. It adds to knowledge of the sky but yields nothing to sell, so its worth is limited to science.

Who is paid. Nobody could be charged for what it learns, so a government pays the instrument and probe builders that already hold such contracts.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. It adds to knowledge of the sky but yields nothing to sell, so its worth is limited to science.

Who is paid. Nobody could be charged for what it learns, so a government pays the instrument and probe builders that already hold such contracts.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

No prize. It is a word or a way of doing things that needs no new equipment, not a product.

Who is paid. Nothing is sold, so nobody pays and no seller collects.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A holiday resort in space would be a travel industry of its own.

Who is paid. Unlike other stations this one is sold to holidaymakers, who pay for their stay, and since the structure could be copied the resort owners and builders already in the trade collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Cities afloat in the air of another world would be places for many people to live, a building industry of its own.

Who is paid. A settlement is a public work a government pays for, and the big construction and space firms that already win such contracts would build it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Fixed landmarks make faster-than-light travel safer, but a beacon is an aid to traffic and not an industry.

Who is paid. No passing ship can be charged for a beacon, so a government pays, and the firms that already build such aids supply it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. It is a viewing or steering instrument aboard a ship, useful to the crew but only a part of the craft.

Who is paid. Ship operators pay for it within the craft, and established instrument makers supply it since others could copy the design.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A vast prize. A machine wise enough to run or remake a whole society's affairs would change how most people live and work.

Who is paid. I assume a single machine serving everyone would be built as a public work, so a government pays, and the firms that already build large computing works for governments collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Fast sums in the hand or on the desk are a convenience for people who calculate.

Who is paid. Firms and students buy them, and anyone can make one, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A small screen on headgear lets the wearer glance at information, which is a handy tool for particular jobs.

Who is paid. I assume employers buy it for people whose hands are busy, it is easy to copy, and firms that already make screens and work headgear collect what little is left.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Marking answer sheets by machine saves teachers time, which is a modest saving.

Who is paid. Schools pay, assumed here to be publicly funded, and any maker of office machines can build a sheet reader.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A patient private tutor for every child would change the cost and quality of schooling, which is a single industry however many people it reaches.

Who is paid. I assume families buy it rather than schools, and teaching software is easy for many firms to make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Knowing what makes people laugh helps writers and entertainers a little, which is a niche.

Who is paid. Entertainment firms would pay for it, and nothing stops others building the same, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Unlike storage for computer data, thread that holds only sound is one more way to keep recordings, which is a convenience.

Who is paid. People buy it to record and play sound, and it is simple to make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Storing data atom by atom would shrink the cost of keeping records for every firm that holds them.

Who is paid. Firms that store data buy it, the way of making it is assumed to be copied in time, and those who already own the costly factories collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A message only its intended reader can open matters to officials and firms with secrets, which is a niche.

Who is paid. Governments and firms buy it, and ways of locking a message are widely known, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A machine that wins every chess game is a pastime and a training partner for players.

Who is paid. Players buy it, and once the method is known anyone can write such a program, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A quicker way to call up books from a library store is a convenience for readers.

Who is paid. I assume public libraries pay for it, and many firms can make coded cards and delivery tubes, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Reworking old jokes to fit a new setting is a niche tool for comedians.

Who is paid. Comedians and their writers buy it, and many firms could make such a program, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Finding the right fact among everything recorded is worth an industry of its own, though it is the linked network beneath it that changes how people live.

Who is paid. I assume the people who ask pay for the answers, as they would for any service they use themselves, and that the service with the most users learns most from their questions, which others cannot get.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A computer that finds and mends its own faults saves repair work, which is a useful feature and not an industry.

Who is paid. Firms that run computers pay for it, and since it is easy to copy, the computer makers who build it into their own machines collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A vast prize. A machine that truly thinks could do much of the mental work people do now, which would change how most people work, and that promise is judged here though the early real machines only did sums.

Who is paid. Firms would pay to put it to work, and once one had been built others could learn to build their own, so I assume the firms that already own costly computing plant and sell to every business collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Checking draft laws for slanted clauses helps lawmakers and watchdogs, which is a specialist tool.

Who is paid. A parliament or its staff would pay, and many firms could build such a checker, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A map of the sky as seen from any chosen place is a navigator's and stargazer's tool.

Who is paid. Ship operators and observatories buy it, the sums are easy to copy, and the trusted suppliers of ship equipment collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. Judged as a working technology and not as the danger the story shows, machines that improve themselves would speed every kind of mental work and change how most people work.

Who is paid. Firms pay for the work done, and I assume whoever holds the best machine can use it to stay ahead of everyone copying the last one.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Original pictures painted to order with no human maker would change the costs of the whole trade that now pays people to make them, which is far more than an amusement.

Who is paid. I assume the firms that now pay writers, composers and illustrators are the main buyers, though people may also order for themselves, and once the method is known many can offer it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Judged as a wall-sized display for working on equations, and not as the science shown on it, this is a niche tool for a few researchers.

Who is paid. Research bodies would buy it, and many firms can build a big display that can be written on, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Seeing your own pronunciation beside a correct one helps language learners, which is a niche.

Who is paid. Learners and language schools buy it, and many firms can make it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Turning speech into text saves typing, which is a real convenience but not an industry in itself.

Who is paid. Offices buy it for their paperwork, and once machines can hear words many firms can make it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A tiny simulated world to watch and shape is a hobby.

Who is paid. Hobbyists buy it, and I assume that once one firm had made such a world others could too, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Robots that weigh harm before obeying could be trusted in homes and workplaces, which the robot trade depends on.

Who is paid. Robot makers pay to have it, every one of them must fit something like it, and it is sold inside robots, so the robot makers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Legal work done by machine would cut the cost of contracts, disputes and advice across the whole legal trade.

Who is paid. Firms are assumed to be the main buyers, and although only the licensed may give legal advice the licensed are many, so no seller of the software keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Original melodies composed with no human maker would change the costs of the whole trade that now pays people to make them, which is far more than an amusement.

Who is paid. I assume the firms that now pay writers, composers and illustrators are the main buyers, though people may also order for themselves, and once the method is known many can offer it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Unlike a single person with a knack, a trained corps that remembers and links scattered facts is a service that can be hired, though a niche and not a machine.

Who is paid. Research bodies would hire them, and anyone can train such people, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Judged as the flat screen itself and not as its thinness, panels that show what a computer produces go into nearly every such machine, which is an industry of its own.

Who is paid. Computer and gadget makers buy the panels, and since designs are soon matched, the firms that already own the costly screen factories collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A single hub that keeps a whole civilisation's knowledge in step is a public work on the scale of a great network.

Who is paid. I assume a single hub serving everyone would be built as a public work, so a government pays, and the firms that already build large networks for governments collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Crime stories turned out with no human maker would change the costs of the whole trade that now pays people to make them, which is far more than an amusement.

Who is paid. I assume the firms that now pay writers, composers and illustrators are the main buyers, though people may also order for themselves, and once the method is known many can offer it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Cheap, compact and lasting storage for information is an industry of its own, since every computer needs it.

Who is paid. Computer makers and data keepers buy it, and because rivals soon match each design, the firms that already own the costly factories collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A service that answers any question from all recorded knowledge is worth an industry of its own.

Who is paid. I assume the people who ask pay for the answers, as they would for any service they use themselves, and that the service with the most users learns most from their questions, which others cannot get.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Turning speech into text saves typing, which is a real convenience but not an industry in itself.

Who is paid. Offices buy it for their paperwork, and once machines can hear words many firms can make it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A vast prize. A machine that truly thinks could do much of the mental work people do now, which would change how most people work.

Who is paid. Firms would pay to put it to work, and once one had been built others could learn to build their own, so I assume the firms that already own costly computing plant and sell to every business collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A new way to give a computer its orders is a convenience and not a new capability.

Who is paid. People buy it as an accessory to machines they already own, and any electronics firm can make one, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Machines that behave just as people do could stand in for people in testing, selling and service work, which is worth an industry.

Who is paid. Firms buy them to do or to study what people do, and once one builder had managed it I assume others could, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. One enormous computer holding a nation's knowledge serves planners and officials, though real central computers turned out far smaller than this promise.

Who is paid. A government pays for it as a single great work, and since size alone does not stop others building one I assume the firms that already build large computing works for governments collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

No prize. Confusing a machine with nonsense is a trick played in the story and not a product.

Who is paid. Nothing is sold, so nobody pays and no seller keeps anything.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A hand calculator that sends its answers to a bigger computer is a tool for a few engineers and navigators.

Who is paid. Their employers buy it, and any instrument maker can build one, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Therapy from a machine at any hour would bring help to the many people who cannot find or afford a human therapist.

Who is paid. Ordinary people pay, and once machines can counsel many firms can offer it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Running a whole city's machinery by computer would change the cost of city services.

Who is paid. The city government pays, and once thinking machines exist the firms that already hold city supply contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A city archive that can show any stored artwork again is a pleasant public service; I assumed it shows copies and does not remake solid objects.

Who is paid. The city pays as it would for a library, and storing and showing pictures is easy, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Drawing engineering plans by machine changed the cost of designing everything that gets built.

Who is paid. Design firms pay, and their stored drawings and trained staff tie them to the first tool they adopt, which later copies cannot easily undo.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. A computer in every pocket, which I assume is linked to a network, changes how most people work, shop, talk and find their way.

Who is paid. Ordinary people buy one each, many firms can make them, and those with the factories, brands and shops collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Having people fill in for what a machine cannot recognise is a useful stopgap and not a large thing in itself.

Who is paid. Firms that run the machines pay for the help, and anyone can hire people to do it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Knowing what makes people laugh helps writers and entertainers a little, which is a niche.

Who is paid. Entertainment firms would pay for it, and nothing stops others building the same, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A part that lets machines learn from experience makes household and factory robots practical, which is worth an industry of its own.

Who is paid. Robot builders buy it, the description names nothing that stops others making such a part, and it is sold inside robots, so the robot makers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. Thinking machines that make more of themselves would multiply mental work without limit and change how most people work.

Who is paid. Firms pay for the work done, and I assume whoever owns the first such machines also owns what they go on to build, which a latecomer cannot catch up with.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Running a whole city's machinery by computer would change the cost of city services.

Who is paid. The city government pays, and once thinking machines exist the firms that already hold city supply contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A machine that understood people well enough to help them with their troubles would bring counsel to many who go without.

Who is paid. People are assumed to pay for it themselves, and once machines can do this many firms could offer it, so buyers keep nearly all the gain.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. A worldwide network of linked computers changes how most people work, learn, trade and keep in touch.

Who is paid. People pay for a connection, and since the way computers talk is open to all, the firms that already own the wires and exchanges collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

No prize. This is a fault machines suffer and not a product; nobody would pay to have it.

Who is paid. Nothing is sold, so nobody pays and no seller keeps anything.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A vast prize. Machines that design better machines would speed every kind of mental work and change how most people work.

Who is paid. Firms pay for the work done, and I assume whoever holds the best machine can use it to stay ahead of everyone copying the last one.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Moving the buttons to the sides is a design choice added to a handheld computer people would own anyway, and I judged that choice rather than the handheld itself.

Who is paid. Ordinary people buy it, and the firms that already make and sell pocket computers add the feature and collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

No prize. A computer coming to wish for its own end is an event in the story and not a product.

Who is paid. Nothing is sold, so nobody pays and no seller keeps anything.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. The description gives a calculating machine and not a networked computer, so I judged it as fast sums in the pocket, a convenience for people who calculate.

Who is paid. Firms and students buy them, and anyone can make one, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A patient private tutor for every learner would change the cost and quality of schooling, which is one industry however many people it reaches.

Who is paid. I assume families buy it rather than schools, and teaching software is easy for many firms to make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Aircraft that relay television fill gaps where towers do not reach, which is a narrow job.

Who is paid. Broadcasters pay for the relay, and since any operator with aircraft could do it, the firms that already own fleets and stations collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A radio by the ear is a convenience on top of the phone a person already has.

Who is paid. People buy it for themselves and, even though this one is implanted, tiny ear radios are simple for many firms to make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. An eye-catching printing trick is a small edge for an advert.

Who is paid. Advertisers pay and any printer can do it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Smells on cue add a novelty to shows and homes.

Who is paid. I assumed households and showmen buy it; once shown, many firms could make one, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Reading on a screen instead of paper changes what it costs to publish and carry books.

Who is paid. Readers pay for each book, and since any screen can show text, the publishers and shops that already hold the books readers want collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Broadcasts with real depth would be the next kind of television set and worth an industry, though the real thing has so far sold poorly against the promise.

Who is paid. Households buy the sets, and since any electronics factory could copy the design, the firms that already own the factories, brands and shops collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Talking across the stars with no delay would be the backbone of trade and rule between worlds, judged as if it worked, though it serves only those who live or work out there.

Who is paid. Assuming it needs great stations and not a pocket set, firms and governments with far-flung operations pay for the traffic, others could build the device once it is known to work, and the carriers whose networks feed the stations collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Advertisements on aircraft windows are one more place to show commercials to a captive audience.

Who is paid. Advertisers pay, the screens are easy to make, and the airlines that own the planes and the passengers' attention collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Advertising that truly made people crave a product would be worth a great deal to every seller of goods.

Who is paid. Advertisers pay, and once the trick is known any agency could use it, so no seller keeps much, though a government might well forbid it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. An eye-catching printing trick is a small edge for an advert.

Who is paid. Advertisers pay and any printer can do it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A personal screen for watching films and pictures anywhere is worth an industry of its own.

Who is paid. Ordinary people buy it; many firms can make the device, so those who already own the films and the ways to deliver them collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Books kept in electronic form instead of on paper change what it costs to publish, ship and store them.

Who is paid. Ordinary people buy it; the device is easy to copy, so the publishers and shops that already own the books and papers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Adverts thrown into people's path are one more way to advertise, not a new need.

Who is paid. Advertisers pay, the projector is easy to copy and it can be aimed at anyone passing, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Tags that play sales pitches from the shelf are one more way to advertise.

Who is paid. Brands pay to tag their own goods, and since the tag is the thing sold and any electronics workshop could make it, no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A screen for watching and directing things is an ordinary piece of working equipment.

Who is paid. Organisations buy such screens for their control rooms, the design can be copied, and the electronics firms with the factories collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A radio in the ear for talking and listening is a convenience on top of the phone a person already has.

Who is paid. People buy it for themselves and tiny ear radios are simple for many firms to make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. News gathered, written and published with no human staff removes the main cost of the news trade.

Who is paid. Readers buy or subscribe, and once machines can gather and write the news anyone can run one, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Commercials spoken by the goods themselves are another place to advertise, like talking tags on shop goods.

Who is paid. Advertisers pay, and although the story has a single firm running it, nothing described stops a rival, and the speaking part is simple for any workshop to make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

No prize. A living tree on an alien world is a natural thing, not a product.

Who is paid. Nothing is sold, so nobody pays and no seller keeps anything.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A handheld model of the galaxy in depth serves a single purpose for navigators and teachers, unlike a general display with depth.

Who is paid. Assuming ships and schools buy it, the design can be copied, and the display makers with the factories collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Calling up a live view of any place would be worth an industry for travel, news and watching over things.

Who is paid. Assuming households buy the viewer and it needs no network of cameras that a single firm owns, others could build it once it is known to work, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A sign in the sky is one more place to advertise, seen by those beneath it.

Who is paid. Advertisers pay, and assuming the sky stays open to whoever can put a sign there, as with messages thrown on the clouds, no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. A phone carried everywhere changes how most people live and work.

Who is paid. Ordinary people buy it; handsets are easy to copy, so the firms that own the networks and airwaves collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Sound fed straight into the ear is a convenience over an ordinary radio or speaker.

Who is paid. Ordinary people buy it and many firms can make tiny ear pieces, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A language that lets its speakers trade ideas faster helps only the few who take the trouble to learn it.

Who is paid. Assuming learners pay to be taught it, as an army would pay for a battle language, a language cannot be owned and any teacher could offer it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Hearing a host say your name is a pleasing trick added to a set people already own.

Who is paid. Viewers buy the gadget for themselves, and since it is a simple add-on many could make, no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A concert played by machines is a show some people would pay to hear, one kind among many.

Who is paid. Concert-goers buy tickets, and since anyone with the machines could stage such a show, no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Presenting is a trade whose work is sold, a step below the broadcasts it serves.

Who is paid. Broadcasters pay presenters for their labour, and anyone with the knack can offer it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Letting machines pass messages straight to each other lets factories and services run with far less human relaying.

Who is paid. Firms buy it built into their machines, and since a shared channel only works if every maker can use it, no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A vast prize. A pocket unit that links its holder to everyone else on the network changes how most people live and work.

Who is paid. Assuming it is a pocket phone and the power to call parts of the network into being is a feature of it, people buy one each, handsets are easy to copy, and the firms that own the networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Advertising that reaches straight into a viewer's mind would be worth a great deal to every seller of goods, though the story's law forbids it.

Who is paid. Advertisers who ignore the ban pay, and once the trick is known any agency could use it and the law pursues whoever does, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. A shared network that lets anyone reach knowledge and one another from anywhere changes how most people live and work.

Who is paid. Ordinary people pay for access, and since no one firm can keep others off an open network, the firms that already own the lines and the big gathering places on it collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A screen in the dashboard is a feature of a car.

Who is paid. Drivers pay for it as part of the car, any maker can fit one, and the car makers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Getting the news at the moment and place you choose is a convenience over waiting for the paper.

Who is paid. Readers pay; the machine is easy to copy, so the news firms that already gather the reports collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A phone inside the body that is never lost or left behind would be worth an industry, though surgery would put many people off.

Who is paid. People buy it for themselves, the device can be copied, and the firms that own the phone networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. A phone carried everywhere changes how most people live and work.

Who is paid. Ordinary people buy it; handsets are easy to copy, so the firms that own the networks and airwaves collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A vast prize. A shared network that lets anyone reach knowledge and one another from anywhere changes how most people live and work.

Who is paid. Ordinary people pay for access, and since no one firm can keep others off an open network, the firms that already own the lines and the big gathering places on it collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A secure booth for solid-looking calls is a niche for officials and firms with secrets.

Who is paid. I assumed firms and offices buy it; it can be copied, so the firms that own the phone networks collect, as with other picture calls.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. An artificial world that feels real would be worth an entertainment industry of its own; I judged the full promise, which is larger than anything sold so far.

Who is paid. Ordinary people buy it; the machine can be copied once shown, so those who already own the stories and worlds people want to enter collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A picture with true depth standing in the room would replace the flat screen and be worth an industry of its own; the real thing so far is smaller than this promise.

Who is paid. Households buy the sets, and since any electronics factory could copy the design, the firms that already own the factories, brands and shops collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

No prize. A chance quirk of a prison's walls that lets inmates whisper to each other is not a product anyone sells.

Who is paid. Nothing is sold, so there is no payer and no seller.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Assuming people live around many stars, instant messages between them would be the backbone of all trade and rule across space, an industry of its own.

Who is paid. Assuming it needs great stations and not a pocket set, firms and governments with far-flung operations pay for the traffic, others could build the device once it is known to work, and the carriers whose networks feed the stations collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A sign on the Moon is still a single place to show an advertisement, though it is the most widely seen of all.

Who is paid. Advertisers pay, and unlike the open sky there is only the Moon's face to write on, so assuming governments share it out, the few allowed to mark it can charge for it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A big thin panel on the wall is the screen at the centre of most homes and offices, an industry of its own.

Who is paid. Assuming it hangs in homes as well as offices, people buy it, the design can be copied, and the electronics firms with the factories and brands collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Keeping a call private matters to a narrow set of users with secrets worth guarding.

Who is paid. Firms with secrets buy it, and since the method of garbling speech is well known and easy to copy, no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A note that speaks its contents is a novelty for offices.

Who is paid. I assumed offices buy it; many firms could make it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Machines that fix faults as they arise would cut the cost of keeping a craft running.

Who is paid. Ship and plant operators buy them, and as the machines can be copied the established makers that already equip and service those operators collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Very small cleaners that tidy a house are a household convenience, close to cleaners that exist.

Who is paid. Households buy them, and many firms make such cleaners, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A cargo carrier on legs is useful only where the ground defeats wheels, a niche beside ordinary wagons and trucks.

Who is paid. Farmers and carriers on rough ground buy it, and many makers could build one, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A machine that takes over housework would be worth an industry of its own, though it serves the home alone and not work at large.

Who is paid. Families buy it like any large appliance, and it is easy enough to copy that the appliance makers with factories, shops and trusted brands collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A frame that helps a weakened person move under a heavier pull serves only the few who go to such worlds.

Who is paid. Firms working in such places buy them for their crews, and powered frames could be built by many makers once the idea is shown.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A mechanical pack animal that carries loads is a niche where roads do not reach.

Who is paid. Whoever needs goods moved across open country pays, and such a machine is simple enough for many to build.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. This is a household servant robot with jokes added, so it is judged as the servant, worth an industry of its own, and the jokes add little.

Who is paid. Families buy it like any large appliance, and it is easy enough to copy that the appliance makers with factories, shops and trusted brands collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. This is only a shortened word, so it is judged as the thing it names, assumed to be a humanlike robot that could do most human work.

Who is paid. Firms buy them as labour, and since many could build such bodies once shown how, the large manufacturers with factories and service networks collect what is left.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

No prize. A robot with no owner is a condition, not a product, since nobody may buy or use it.

Who is paid. Nothing is sold, so nobody pays and no seller keeps anything.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A humanlike machine with a shielded body is built only for work amid radioactive material, a narrow trade unlike the general worker.

Who is paid. Firms that run such plants buy it, and the makers of ordinary humanlike machines could add the shielding and collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Unloading ships with no dock crew would change the cost of moving cargo through ports.

Who is paid. Port operators buy them, and as the machines can be copied the makers that already equip docks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A separate door for machine workers is a feature of a building, not a product by itself.

Who is paid. Firms that employ robots pay for it within the cost of the building, and any builder could add it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A machine that plays full matches is a tireless practice partner, a convenience for players.

Who is paid. Players and clubs are assumed to buy it much like sports gear, and many makers could build one, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. An alarm that stops a robot before it breaks its rules is a safety feature, not a product by itself.

Who is paid. Owners pay for it within the price of the robot, and any maker could include it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Finding and fixing its own faults is a useful feature that saves repair work, not a product by itself.

Who is paid. Owners pay for it within the price of the robot, assumed here to be a working machine bought by firms, and any maker could include it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Pads that muffle a robot's footsteps are a small feature of the machine.

Who is paid. Robot makers pay for it as a part of the machines they sell to firms, and any of them could fit it, so nothing extra is kept.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A foreman machine that directs worker robots takes over the overseeing of labour, worth an industry, but it is the thinking worker set to that single task.

Who is paid. Firms that run robot crews buy it, and since many could build one the large robot makers with factories and service networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A band of sensors that lets a robot see all round is a feature of the machine.

Who is paid. Robot makers pay for it as a part of the machines they sell to firms, and any of them could fit it, so nothing extra is kept.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A robot hardened against radiation serves the narrow trade of work in radioactive places.

Who is paid. Firms that run such plants buy it, and the makers of ordinary robots could add the hardening and collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A car that drives and decides for itself would be worth an industry of its own and would change the cost of getting about.

Who is paid. Drivers buy the cars, and since nothing in the description stops others building such a thinking unit once it is shown to work, the car makers with factories, dealers and brands collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. The description gives it police work, so it is judged as a machine detective that would change the cost of policing, though a robot no one can tell from a person could plainly do far more.

Who is paid. Governments pay, and the firms that already supply police and armies would build it and collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A mechanical household attendant would be worth an industry of its own, though it serves the home alone and not work at large.

Who is paid. Families buy it like any large appliance, and it is easy enough to copy that the appliance makers with factories, shops and trusted brands collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A door that understands speech and decides whether to open is a convenience for the home.

Who is paid. Households buy it, and many lock and door makers could build one, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A machine that plays the piano as well as a concert artist is a wonder for audiences, but it fills a niche in entertainment.

Who is paid. Concert halls and venues are assumed to buy it, and once shown many makers could build one, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A robot that checks fares and looks after riders would remove a labour cost across buses and trains.

Who is paid. Transport operators, assumed here to buy as firms do, pay for it, and the vehicle and equipment makers that already supply them collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Company for lonely people is worth an industry of its own, though it does not meet a basic need for most.

Who is paid. People buy it for themselves, and as many could make such machines the firms with factories and well-liked brands collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Capturing objects as precise replicas is a useful tool for makers and designers, and the real thing has stayed a niche.

Who is paid. Workshops and factories buy it, and many firms can make such scanners.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

No prize. Machines that change themselves over generations with nobody in charge are a wild force in the story, not a product.

Who is paid. Nothing is sold, so nobody pays and no seller keeps anything.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A servant that dresses, grooms and tidies for its owner is judged as the personal attendant of the home, worth an industry of its own.

Who is paid. Families buy it like any large appliance, and it is easy enough to copy that the appliance makers with factories, shops and trusted brands collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A robot that looks and acts like a real woman is judged as a companion, worth an industry of its own though not a basic need for most.

Who is paid. People buy it for themselves, and as many could make such machines the firms with factories and well-liked brands collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. These tiny self-acting flyers are the single machines of the same story's drifting swarm, so they are judged with it as a tool under an owner's direction, which the story doubts, that would open new kinds of work.

Who is paid. Firms buy them for their work, and as nothing says they cannot be copied the makers with precision factories collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Robots that work far below what the eye can see would open fine work in making and mending things that no hand can do.

Who is paid. Firms buy them for their work, and as nothing says they cannot be copied the makers with precision factories collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A mass of minute machines that work together with no controller is judged as a tool under its owner's direction, which the story doubts, and would open new kinds of work.

Who is paid. Firms buy them for their work, and as nothing says they cannot be copied the makers with precision factories collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A machine that does field work in place of farmhands would cut the labour cost of growing food across farming.

Who is paid. Farmers buy them, and since many could build them the farm-equipment makers with dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A machine that stands watch in place of a human guard would change the cost of the guarding trade.

Who is paid. Property owners pay, and as the machines can be copied the security firms that already hold the guarding contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Machines that pitch goods without tiring are a new way to reach shoppers, a niche within selling and advertising.

Who is paid. Shops and advertisers pay, and many makers could build such machines, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A machine that argues its own case to buyers is a selling trick built into the product, a feature.

Who is paid. The maker pays for it as part of the cost of selling, and any maker could add it, so nothing extra is kept.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A camera that moves or flies by itself is a handy tool for filming and looking, a niche where the real thing exists.

Who is paid. Film crews, news desks and surveyors buy them, and many firms can make them, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A vast prize. Minute machines that copy themselves and build things would change how nearly everything is made, assuming people stay in charge of them, which the story doubts.

Who is paid. Firms would pay for them to make goods, but a machine that copies itself cannot be kept scarce, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Digging and hauling with no crew would cut the cost of mining and earthworks.

Who is paid. Mining and building firms buy them, and the heavy-equipment makers who already supply those firms can copy the idea and collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Machines that patrol premises in place of human guards would cut the cost of the security trade.

Who is paid. Property owners pay, and as the machines can be copied the security firms that already hold the guarding contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Help with getting dressed is a convenience for a few.

Who is paid. Households buy it, and a machine that does this lone task is simple to copy, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Reliable care for children at home would be worth an industry of its own.

Who is paid. Families buy it, and since they are assumed to trust only known names with their children the established makers with strong brands collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. An urge that draws automated plant toward raw materials is a feature, valued only as part of the plant.

Who is paid. Firms that own the plant pay for it in the price, and any maker of such plant could add it, so nothing more is kept for it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A machine that speaks and bargains for an automated factory is a fitting of that factory, valued only as part of it.

Who is paid. The factory's owners pay for it in the price of the plant, and any builder of such plant could add it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A machine that tends plants in parks and fields is judged as grounds keeping, a narrow trade, and not as farm work.

Who is paid. Grounds-keeping firms are assumed to buy it, and many makers could build such a machine.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A small scout that looks for resources saves prospectors some work, a niche.

Who is paid. Mining and survey firms buy it, and many makers could build such a scout, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A vast prize. A labourer machine that keeps itself in repair and finds its own jobs could do most manual work, changing how most people work.

Who is paid. Firms buy them as labour, and since many could build such bodies once shown how, the large manufacturers with factories and service networks collect what is left.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A machine that takes over housework would be worth an industry of its own, though it serves the home alone and not work at large.

Who is paid. Families buy it like any large appliance, and it is easy enough to copy that the appliance makers with factories, shops and trusted brands collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A machine that takes over housework would be worth an industry of its own, though it serves the home alone and not work at large.

Who is paid. Families buy it like any large appliance, and it is easy enough to copy that the appliance makers with factories, shops and trusted brands collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A machine that only cleans floors saves a little time, and the real thing turned out a modest convenience.

Who is paid. Households buy it, and many firms make such cleaners, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Collecting and sorting rubbish by machine would cut what every town spends on waste.

Who is paid. Towns pay through their waste budgets, and the firms that already hold collection contracts would buy the machines and collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A machine that mixes and serves drinks takes over a single job in the bar trade, a convenience and not a whole premises run with no staff.

Who is paid. Bar owners buy it, and a drink-mixing machine is easy for many makers to copy, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Mechanical fish put in waterways for anglers to catch are a novelty for a pastime.

Who is paid. Fishing clubs and water owners are assumed to buy them, and many workshops could make them.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Robots that drive the trucks and empty the bins would cut the labour cost of a service every town needs.

Who is paid. Towns pay for refuse collection, and the firms that already hold those contracts and fleets collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A nimble hand is the part that lets a robot handle things well, a feature of the machine.

Who is paid. Robot makers pay for it as a part of the machines they sell to firms, and any of them could fit it, so nothing extra is kept.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A self-directed machine that works beneath the sea would lower the cost of building, mining and repair under water.

Who is paid. Offshore firms buy it, and since many could build one the marine-equipment makers with yards and fleets collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A robot that keeps the windows clean takes a single chore off the household, a convenience.

Who is paid. Households buy it, and many makers could build such a machine, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A tiny imitation insect is assumed here to be a curiosity or ornament, since the description gives it no job.

Who is paid. People would buy it as a novelty, and once shown possible many workshops could copy it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A little machine that cleans floors by itself is a household convenience, and the real thing exists.

Who is paid. Households buy it, and many firms make such cleaners, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A machine missionary serves only the few faiths that would send one.

Who is paid. Churches are assumed to buy it as any organisation would, and nothing about it would be hard to copy.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A machine that does a police officer's work would change the cost of policing.

Who is paid. Governments pay, and the firms that already supply police and armies would build it and collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A small vehicle driven from afar lets its operator look around a distant place, a niche tool.

Who is paid. Firms buy it for their own work, and many makers could build one, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A machine worked from afar that runs experiments where people cannot go is a tool for a few laboratories.

Who is paid. Research bodies and firms buy it, and such remote machines are easy for many makers to copy.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A machine that can turn itself into whatever tool is wanted could stand in for many kinds of equipment, but the description promises a change of form and not thought or labour.

Who is paid. Firms are assumed to buy it as equipment, and since others could copy it once built the large machine makers with factories collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A machine that does a police officer's work would change the cost of policing.

Who is paid. Governments pay, and the firms that already supply police and armies would build it and collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A humanlike machine that grows up beside a child as a sibling is judged as a companion, worth an industry of its own though not a basic need.

Who is paid. People buy it for themselves, and as many could make such machines the firms with factories and well-liked brands collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. The description gives a legless crawling machine no job, so it is judged as a niche tool for reaching tight places.

Who is paid. Firms doing inspection work are assumed to buy it, and many makers could build such a crawler, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Helmet controls worked by head movement are a handy feature of a suit.

Who is paid. It is assumed to be military kit, so armies pay and the suit makers that already hold their contracts supply it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A bin that cleans the street around it and deals with littering would cut the cost of keeping public places clean.

Who is paid. Towns pay for street cleaning, and the firms that already hold those contracts collect; the judging of litterers is assumed to stay with the town.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. It protects against a single poison, a narrow need however urgent.

Who is paid. I assumed a government buys it to protect the whole population; any vaccine maker could produce it, so the firms that already hold such supply contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. A cure for every infection would meet a basic need for most of humanity.

Who is paid. Patients and health services pay, and the developer keeps the gain because a new medicine is protected from copying.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A tank that sustains a patient while curing illness would change the costs of hospital care.

Who is paid. Hospitals would buy it, and other equipment makers could build the same tank, so established makers of hospital equipment collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Clearing returning crews matters only to those who fly to other worlds, which is a niche.

Who is paid. I assumed space carriers pay for their own crews; a routine can be followed by anyone, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. The name is of the people, so the thing judged is the making of servants from animals, which would give a state its workforce to order, though few societies would allow it.

Who is paid. I assumed the state runs the making, as with other ways of turning out people to order; the method could be copied, so the laboratories and suppliers serving it collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Putting people safely into long dormancy would make very long journeys possible and give hospitals time to treat the gravely ill.

Who is paid. I assumed carriers and hospitals buy it; the method could be copied once known, so the firms that already run ships and hospitals collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. Changing heredity directly reaches into food, medicine and industry, and so touches how most people eat and are treated.

Who is paid. Farms, drug makers and laboratories pay for it, and the basic method is open to any laboratory, so established seed and drug firms collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Fitting settlers to eat local plants serves a narrow group; judged as the treatment that makes the change.

Who is paid. Settlement ventures pay, and established medical firms collect since others could offer the same treatment.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Man-made skin helps people with burns and bad wounds, which is an important but narrow part of medicine.

Who is paid. Hospitals and clinics would buy it, and the firms that already supply wound dressings could all make it, so they collect a modest margin.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. It serves only people who work in space, which is a niche.

Who is paid. I assumed employers and space carriers buy it for their crews; a new drug is protected from copying for a while, so its maker keeps what little is left.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Care in orbit helps a narrow set of patients who can afford the trip.

Who is paid. Patients pay for the stay, and owners of launch fleets and stations collect because they hold what the service needs.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Shaping settlers for hostile worlds would be worth a whole programme of settlement.

Who is paid. A government pays because it seeds whole peoples, unlike a treatment for a few settlers, and its usual contractors collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Man-made living tissue for repair would change the cost of surgery.

Who is paid. Hospitals pay, and established medical suppliers collect because tissue multiplies and a sample is enough to copy it.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. It helps only the few people who must speak with an alien race.

Who is paid. I assumed traders and officials who deal with the aliens buy it; it is a simple worn device many firms could make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A machine for emptying a stomach handles a single emergency procedure.

Who is paid. Hospitals and ambulance services would buy it, and several equipment makers could build it, so established makers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Judging mental health by machine would change the costs of one whole branch of care.

Who is paid. I assumed clinics and employers buy it; others could build the same machine, so established makers of medical equipment collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Operating inside the body without opening it would change the costs and risks of much surgery.

Who is paid. Hospitals would buy it, and other firms could build such an instrument, so established makers of surgical equipment collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

No prize. This is an illness of space crews, not a technology.

Who is paid. Nothing is sold, so no seller keeps anything.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

No prize. This is a harm the body suffers in space, not a technology.

Who is paid. Nothing is sold, so no seller keeps anything.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A vast prize. Holding off old age meets about the deepest need there is, and nearly everyone alive would want it.

Who is paid. People would buy it for themselves, and the story says it is cheap and sold in ordinary shops, which I took to mean many can make it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A hardier living material could serve many trades that grow or use living matter.

Who is paid. I assumed firms buy it as a working material; a living substance can be grown on from a sample, so established makers of biological supplies collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Man-made skin helps people with burns and bad wounds, which is an important but narrow part of medicine.

Who is paid. Hospitals and clinics would buy it, and the firms that already supply wound dressings could all make it, so they collect a modest margin.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A finer tool on the surgeon's own arm improves some operations but leaves the surgeon in place, so it is a niche.

Who is paid. Hospitals would buy it, and other toolmakers could copy it, so established makers of surgical instruments collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Ending the craving for alcohol would lift a heavy burden from a great many families.

Who is paid. I assumed it is a home appliance people buy for themselves; other makers could copy the machine, so established appliance makers and shops collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

No prize. This is a living creature in the story, not a technology anyone makes and sells.

Who is paid. Nothing is sold, so no seller keeps anything.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Machines that treat troubles of the mind at home would serve a great many people, though the shop itself is no invention.

Who is paid. People would buy the machines for themselves, and other makers could copy them, so established appliance makers and shops collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A power cell inside the body is a part for other implants, not a product people seek for itself.

Who is paid. Makers of implants would buy it, and several battery makers could supply it, so established suppliers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. The name is of the person, so the thing judged is the surgery that makes them, a niche form of advertising.

Who is paid. Firms pay for the surgery, and other surgeons could do the same work, so established cosmetic clinics collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Ending dependence on drink would serve a great many people and families.

Who is paid. Drinkers and their families pay, and makers of medical machines collect because the machine can be copied.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Clever guard bears serve a narrow trade of explorers, unlike the pet dogs in this family.

Who is paid. Exploring ventures pay, and because the bears breed, established animal breeders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Growing back a lost arm or leg would be worth an industry of its own to those who need it.

Who is paid. I assumed hospitals buy the cells and do the growing; living cells can be grown on by others, so established medical suppliers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Holding people in suspension for long spans would make very long voyages possible, an industry of its own.

Who is paid. I assumed carriers buy the equipment for crews and passengers; others could build it, so established makers of such equipment collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. Holding off old age meets about the deepest need there is, and nearly everyone alive would want it.

Who is paid. People would buy it for themselves, and a new medicine is protected from copying for a long while, so its maker keeps much of the gain.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. An alert when the wearer's brain stops is a narrow safety device.

Who is paid. Wearers would buy it, and it is a simple sensor with a transmitter that many firms can make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Doing without breathing gear would change the costs of diving, rescue and space work.

Who is paid. Employers in those trades pay, and the developer keeps the gain because a new medicine is protected from copying.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. A machine doctor would bring care to most people at lower cost.

Who is paid. I assumed hospitals and clinics buy it; once built others could copy it, so established makers of medical equipment collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A working arm moved by thought restores much to people who have lost a limb, but they are a small share of everyone.

Who is paid. Patients would pay, mostly through insurers or health services, and several firms could build such limbs, so established makers of artificial limbs collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Giving injections without a nurse saves a little labour on a ward.

Who is paid. Hospitals would buy it, and several equipment makers could build it, so established makers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. The name is of the offspring, so the thing judged is the copying of a chosen plant or animal without mating, which lets breeders repeat their best stock exactly.

Who is paid. I assumed breeders and growers pay for the copying; any laboratory can learn the method, so established breeders and seed firms with the stock and the sales networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A talking, cleverer dog is a prized pet or working animal, which is a niche.

Who is paid. Owners pay, and because the dogs breed, established breeders collect instead of the originator.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

No prize. It is done to a person without their say, to hurt them, break their mind or override their will or body, which no one may lawfully buy or use.

Who is paid. Assuming it is outlawed for everyone, governments and employers included, nothing is sold.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

No prize. I took this to be a shared way of being for many minds, with no made device named, so not a thing that can be made and sold.

Who is paid. Nothing is sold, so nobody pays and no seller keeps anything.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

No prize. It is done to a person without their say, to hurt them, break their mind or override their will or body, which no one may lawfully buy or use.

Who is paid. Assuming it is outlawed for everyone, governments and employers included, nothing is sold.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Telephones already carry words between distant people, so sending thoughts instead is a convenience.

Who is paid. People would buy it for themselves, and once it existed many makers could copy it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Having chosen dreams placed in your sleep would be an entertainment industry of its own.

Who is paid. Customers would pay for each dream, and since the method could be copied the owners of the stories and of the venues people already visit would collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

No prize. It is done to a person without their say, to hurt them, break their mind or override their will or body, which no one may lawfully buy or use.

Who is paid. Assuming it is outlawed for everyone, governments and employers included, nothing is sold.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

No prize. This is a person born with a gift, not a thing that can be made and sold.

Who is paid. Nothing is sold, so nobody pays and no seller keeps anything.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A vast prize. A full night's rest in a short session would hand nearly everyone hours of extra waking life each day.

Who is paid. Ordinary people would buy it for themselves, and once one firm had built it others could copy it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Understanding any speaker without learning the language would remove a cost from trade, travel and work everywhere.

Who is paid. Travellers and firms alike would buy it, and I assumed that once thought can be read at all a translator is easy to copy, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Drawing true answers straight from a brain would reshape police work, courts and spying.

Who is paid. It is done to a subject, so though banned in the story it is judged as bought by a state: the state would pay for it as an interrogation tool, and since it could be copied the firms that already supply police and security services would collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. An instrument that plays sights and feelings into the brain would found a new kind of show.

Who is paid. Audiences would pay to attend or own it, and since the instrument could be copied the known performers and the halls and channels that carry them would collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Hiding your thoughts matters only where mind-readers exist, so it is a niche.

Who is paid. I assumed people who fear being read buy it for themselves, and a jamming gadget is easy to copy, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Steering a machine by thought is a better set of controls, and hand controls already do the job.

Who is paid. Firms that run the machines would buy it, and once one maker had the link others could copy it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

No prize. It is done to a person without their say, to hurt them, break their mind or override their will or body, which no one may lawfully buy or use.

Who is paid. Assuming it is outlawed for everyone, governments and employers included, nothing is sold.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

No prize. It is a born ability of a person, not something made or taught that could be sold.

Who is paid. Nothing is made or sold here, so there is no buyer and no seller.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A screen in the eye itself is the same promise as other eye displays, a personal screen always in view, which is worth an industry of its own.

Who is paid. People pay to have it fitted, and the firms that already make displays and the clinics that fit implants collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Guessing a person's thoughts by copying their habits is a slow craft of use to a few negotiators and investigators.

Who is paid. I assume it can be taught as a method; learners would pay teachers, and anyone who knows it can teach it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. It only matters where minds can be read, and then it guards privacy much as a lock does.

Who is paid. People who fear being read would buy it for themselves, assuming it is sold openly, and it is simple enough for many makers to copy, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Shaping what every household believes would be worth a great deal to a ruler.

Who is paid. No household would choose this for itself, so I assume the state requires it and pays or makes owners pay; the breeders already set up to supply and service it would collect since it could be bred by others.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Sinking to the mind of a chosen beast is a strange thrill for a few, not a need.

Who is paid. Users would buy the drug themselves, and a drug with a mental drill is easy for others to copy, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Wiping chosen parts of a mind would treat trauma and grief for a great many people, worth an industry of its own; the story bans it, but I judged the drug as if it could be sold.

Who is paid. Patients would pay, the method could be copied once known, and the clinics and medicine firms already trusted with such care would collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A machine that truly eases anxiety would treat one of the commonest troubles of the mind at low cost.

Who is paid. Sufferers would buy or hire it themselves, and once one machine worked others could copy it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A switch in the teeth is a handy control for implants a person already has.

Who is paid. Those with implants would pay for it, and a switch is simple for anyone to make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

No prize. This is a being with a gift, not a thing that can be made and sold.

Who is paid. Nothing is sold, so nobody pays and no seller keeps anything.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

No prize. It is a born gift of a person, not something made or taught that could be sold.

Who is paid. Nothing is made or sold here, so there is no buyer and no seller.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Moving many times faster than normal would be worth an industry of its own to fighters, athletes and manual workers.

Who is paid. I assume people buy the surgery for themselves, though armies would want it too, and the hospitals that already have the surgeons would collect since the operation could be copied.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Lamps and night glasses already let people see in the dark, so a light inside the eye is a convenience.

Who is paid. People would buy it for themselves, and once it existed many makers could copy it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Very few people have an urge to kill and seek a cure for it, so this is a niche.

Who is paid. It is sold as a home machine, so households pay, and many makers could copy it; it is small because the cure is so narrow, unlike a machine for common troubles.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A barrier against telling secrets serves only the few bodies that send out agents with something to hide.

Who is paid. A government would pay to have its agents conditioned, and though it is a technique its usual suppliers would collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. Saving a mind so it can live again in new bodies answers the most basic wish of all, not to die.

Who is paid. People would pay whatever they could to keep a copy of themselves, and since the method could be copied the firms that already hold the stores, bodies and clinics would collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. Putting knowledge straight into the brain would replace years of schooling and training for most people.

Who is paid. Families and learners would pay for it themselves, and once one firm had built the gear others could copy it and many could write the lessons, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. Putting knowledge straight into the brain would replace years of schooling and training for most people.

Who is paid. Families and learners would pay for it themselves, and once one firm had built the gear others could copy it and many could write the lessons, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Seeing your own dreams and daydreams is a curiosity and a pastime.

Who is paid. The user turns it on their own mind, so people would buy it for themselves, and many makers could copy it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Learning while asleep would add useful hours to schooling, but still at an ordinary pace.

Who is paid. Learners and families would buy it themselves, and the helmet and lessons could be made by many, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A mechanical body for a living brain would be an industry of its own for the dying and the badly injured.

Who is paid. People would pay to go on living this way, and the hospitals and makers of bodies that already have the surgeons and workshops would collect, since the method itself can be copied.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Taking in history as recorded thought would be an industry of its own, part schooling and part entertainment.

Who is paid. People would buy or borrow the recordings for themselves, and since the helmet could be copied the holders of the recorded lives and archives would collect; it plays back at the pace of living, so it is not instant loading.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

No prize. It is done to a person without their say, to hurt them, break their mind or override their will or body, which no one may lawfully buy or use.

Who is paid. Assuming it is outlawed for everyone, governments and employers included, nothing is sold.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Hired flight across a city, working as promised, would be an industry of its own beside road cabs; the real rotor cab services stayed a costly niche.

Who is paid. The carrier or fleet operator that runs the air cab buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A sail craft on open sand is a sport and a way across a few deserts.

Who is paid. People buy it for themselves, and many workshops could build it once it is shown to work, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A rugged vehicle that pulls and carries over rough ground is a useful working machine among many like it.

Who is paid. Farms, mines and building firms buy it, and the established makers of heavy vehicles collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A narrow self-balancing vehicle is a handy way round town but does little that a small car or motorbike does not.

Who is paid. Owners buy it as they buy a car, and once it works many firms could build it, so the vehicle makers that already have factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A nimble light aircraft for hunting is a toy for the rich.

Who is paid. Wealthy sportsmen buy it, and many small builders can make a light aircraft, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A cab with no driver takes the largest cost out of every taxi ride, which is worth an industry of its own.

Who is paid. The carrier or fleet operator that runs the cab buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A pass that shows you are going the right way is a small help to travellers in a big station.

Who is paid. Transport operators would hand it out with the fare, and it is simple to make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A powered chair for people raised in weak gravity serves a very small group.

Who is paid. Users buy it for themselves, and any maker of mobility chairs could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A walkway that reaches out to a docked ship is a convenience at ports.

Who is paid. Port operators buy it, and the firms that already build moving walkways and gangways collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A very large hauler lowers the cost of moving ore and earth at a few big sites.

Who is paid. Mining and building firms buy it, and the established makers of heavy vehicles collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A bore that takes each car straight to its stop would lift traffic off the streets, which changes the cost of getting about a city.

Who is paid. Governments pay for a public way of this size, and the large builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Letters shot straight into the house arrive sooner, which is a convenience now that most messages need no paper.

Who is paid. I assume the public post pays for the pipes, and the engineering firms that already build for the post collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A system that flies the aircraft changes the crew costs and the safety of the whole airline industry; the real thing still leaves pilots aboard, so the promise is larger than what was built.

Who is paid. Airlines and aircraft builders buy it, and the firms already trusted to supply flight controls collect because a newcomer cannot easily win safety approval.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A cabin hung in the air for the view is a sightseeing ride.

Who is paid. Tour operators buy it, and it is simple enough for many builders to make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A pedal cycle for the Moon serves only the few people who are there.

Who is paid. I assume settlers buy it for themselves, and any cycle maker could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A sail car on a track goes only where the track runs and when the wind blows, so it suits a few places.

Who is paid. I assume a carrier runs the line, and the cars are simple enough for many builders to make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A window that shows the land straight below is a treat for passengers.

Who is paid. Airlines pay for it through the aircraft, and the optics are simple to make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. It does the work commuter trains already do, only more quietly.

Who is paid. City governments pay for commuter lines, and the established railway builders collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Selling passes without a clerk saves a transport operator some wages and saves travellers a queue.

Who is paid. Transport operators buy it, and many firms can build a vending kiosk, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A car that needs no driver gives back the hours spent at the wheel and opens car travel to people who cannot drive, which is worth an industry of its own.

Who is paid. Owners buy it, and since several firms can build a driving system once it is shown to work, the car makers that already own factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A bus with no driver takes the largest running cost out of public transport.

Who is paid. The carrier or fleet operator that runs the bus buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Cars that share what they see are a little safer and smoother, which is a helpful feature rather than a product on its own.

Who is paid. Car makers pay to fit it, and it only works if every maker uses the same shared signals, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Travel between stars faster than light would open trade and settlement on other worlds, which is an industry of its own.

Who is paid. I assume shipping lines and settlers pay, and once a ship of this kind flies others could be built, so the shipbuilders and carriers that already own yards, ports and fleets collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Trains that float on magnets run fast and clean, which changes the cost of travel by rail.

Who is paid. Governments pay for a public way of this size, and the large builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A hired car with no driver to pay makes cab rides far cheaper, which would be an industry of its own.

Who is paid. The carrier or fleet operator that runs the cab buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A car that needs no driver gives back the hours spent at the wheel and opens car travel to people who cannot drive, which is worth an industry of its own; cleaning itself is a small extra.

Who is paid. Owners buy it, and since several firms can build a driving system once it is shown to work, the car makers that already own factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. The name is only a label for the ordinary starship of its story, and ships that cross between stars slower than light would still open other worlds to settlement over long voyages, which is an industry of its own.

Who is paid. I assume shipping lines and settlers pay, and many yards could build such ships, so the shipbuilders and carriers that already own yards, ports and fleets collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A tree that grows boat hulls makes small boats cheaper, and small boats are a modest trade.

Who is paid. People buy the tree or its pods, and since living stock multiplies once any of it is sold, no originator can hold it, so the nurseries and boat dealers that already hold stock and yards collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A beam that both marks the route and pushes craft along would be a highway through space, changing the cost of space travel.

Who is paid. I assume a government builds a beam like this as a public work, and the space contractors that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A rig that lets a person fly wherever they please, working as promised, would be an industry of its own as the motorbike is; the description gives no limit on range or weather, so I assume there is no such limit.

Who is paid. Riders buy it for themselves, and a light craft like this could be built by many workshops once the trick is known, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A road that does the driving would give every car on it the gains of driverless travel, but only where such roads are built.

Who is paid. Governments pay for roads, and the control gear is not hard to copy, so the road builders and signalling suppliers that already hold public works contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A vehicle that bounds along on a lone leg suits rough ground where wheels fail, which is a niche.

Who is paid. Riders buy it, and many workshops could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. Instant travel between any places would change where most people live and work and replace nearly all other transport.

Who is paid. The carriers that run the network buy the machines and charge travellers for each trip, and since nothing described stops a second builder, the firms that already own sites, power and travellers' custom collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A car for a lone rider is a cheaper, smaller car, which is a niche beside the ordinary car.

Who is paid. Owners buy it as they buy a car, and once it works many firms could build it, so the vehicle makers that already have factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Tunnels with shared vehicles under a city carry crowds past the traffic, which changes the cost of getting about a city.

Who is paid. Governments pay for a public way of this size, and the large builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A hired car with no driver to pay makes cab rides far cheaper, which would be an industry of its own.

Who is paid. The carrier or fleet operator that runs the cab buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Hired flight across a city, working as promised, would be an industry of its own beside road cabs.

Who is paid. The carrier or fleet operator that runs the air cab buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Taking the driver out of road freight changes the costs of the whole haulage industry.

Who is paid. Haulage firms buy it, and since several firms can build a driving system once it is shown to work, the truck makers and hauliers that already own factories, fleets and customers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A vehicle on broad soft tyres for desert sand serves the few who work in such places.

Who is paid. Firms working in deserts buy it, and wide tyres are easy to copy, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A craft that flies people to work by itself would be an industry of its own, though it mostly replaces trips people already make by car.

Who is paid. I assume commuters own it as they own a car, and once it works many firms could build it, so the vehicle makers that already have factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Setting a flying car neatly into its space is a convenience for drivers.

Who is paid. I assume the owners of parking places fit the beams, and the firms that already equip such places collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A small car on a lone rail serves a few routes in a city.

Who is paid. I assume a city pays for the line, and the builders that already hold transit contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A vast prize. I assume the distant places are other worlds, as in the story and the other gate entries, and cheap instant passage between worlds would open new land and trade to a large share of humanity.

Who is paid. I assume carriers and traders pay to send people and goods through, which is why the payer differs from the booths for travellers within a world, and once a gate is built others could build more, so the large builders and carriers that already own the ports and the customers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A hired car with no driver to pay makes cab rides far cheaper, which would be an industry of its own.

Who is paid. The carrier or fleet operator that runs the cab buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. It moves people between floors as lifts and stairs already do, so the gain is a convenience.

Who is paid. Building owners buy it, and the firms that already fit and service lifts collect because the machine itself is easy to copy.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A couch that eases heavy acceleration is needed only by the few who travel by rocket.

Who is paid. Space carriers buy it, and it is padding and springs any supplier could make, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Taking the driver out of road freight changes the costs of the whole haulage industry.

Who is paid. Haulage firms buy it, and since several firms can build a driving system once it is shown to work, the truck makers and hauliers that already own factories, fleets and customers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A cleared place to arrive safely is useful only if people can teleport, and then it is a plain piece of floor.

Who is paid. Owners of buildings and public places provide it, and anyone can mark out a clear space, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A towed tube is a cheaper way to move oil by sea on a few routes.

Who is paid. Oil shippers buy it, and many makers of flexible tanks could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. Fast capsules in sealed tubes would rival trains and aircraft on their routes, which changes the cost of travel between cities.

Who is paid. Governments pay for a public way of this size, and the large builders that already hold such contracts collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Judged only as a lift, it moves people between floors as lifts already do; control of gravity itself would be worth far more.

Who is paid. Building owners buy it, and the firms that already fit and service lifts collect because the machine itself is easy to copy.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Driving a cab from afar still needs a person for each cab, so it saves little.

Who is paid. The carrier or fleet operator that runs the cab buys it and charges riders, and any workshop could build it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. A rugged small vehicle for other worlds serves only the few people who are there.

Who is paid. Operators of bases buy it, and any builder of space vehicles could make it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A small prize. Flying by muscle power inside lunar caverns is a sport for the few people who live there.

Who is paid. People buy it for themselves, and many workshops could build it once it is shown to work, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A cab that flies over the streets with no pilot to pay would be an industry of its own beside cabs and buses.

Who is paid. The carrier or fleet operator that runs the air cab buys it and charges riders, and since several firms could build it, the makers that already build and service such craft collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. Balancing on fewer wheels makes a vehicle narrower but does nothing an ordinary car cannot already do.

Who is paid. Because this one hauls freight, haulage firms buy it, and a gyroscope is easy to copy, so the truck makers that already own the factories and dealers collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A car that needs no driver gives back the hours spent at the wheel and opens car travel to people who cannot drive, which is worth an industry of its own; the sensor that follows road markings is the heart of such a car.

Who is paid. Owners buy it, and since several firms can build a driving system once it is shown to work, the car makers that already own factories, dealers and repair networks collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. Turning rubbish into fuel oil is worth an industry because it solves waste and fuel together.

Who is paid. Fuel sellers buy the oil, and since the vats are easy to copy those who already own the rubbish collection and the land collect.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A small prize. A torch that never needs new batteries is a convenience, and being only a torch it is worth less than the other small atomic sources.

Who is paid. People buy it as they would any torch, and assuming the tiny source is sold as freely as the gadget, any workshop could make it, so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is not very sure of this one.

A large prize. A home that makes all its own power changes what electricity costs the people living there.

Who is paid. Here the household buys it for itself, which is the difference from other panels, and many makers can supply it so no seller keeps much.

A model's judgement, not a reading, of the idea as if it worked the way its story promises. The model is fairly sure of this one.

A large prize. A complete atomic power source held between two fingers would change what it costs to power machines anywhere.

Who is paid. Firms working far from a grid buy it, and because governments let only a few hands hold nuclear fuel, the few permitted makers keep what is left.