World Without Distance

Most of the Energy expended in the history of the world has been used to move things from one place to another. For thousands upon thousands of years, the rate of movement was very slow -- less than two or three miles an hour, the pace of a walking man. Even the domestication of the horse did not raise this figure appreciably, for though a racehorse can exceed 40 miles an hour for very short periods, the main use of the horse has always been as a show-moving beast of burden and a hauler of vehicles. The fastest of these -- the stagecoaches immortalized by Dickens -- seldom traveled at more than 10 miles an hour on the roads that existed before the 19th Century.

For almost the whole of human history and prehistory, therefore, men's thoughts and their ways of life have been restricted to the tiny band of the speed spectrum between one and 10 miles an hour. Yet within the span of a few generations, the velocity of travel has been multiplied a hundredfold; indeed, there are good grounds for thinking that the acceleration that has taken place round the mid--20th Century will never again be matched.

Speed, however, is not the only criterion of transport, and there are times when it is positively undesirable -- especially if it conflicts with safety, comfort or economics. As for as transportation at ground level is concerned, we may well have reached (if not passed) the practical limit of speed, and future improvements must lie in other directions. No one wants to travel down Fifth Avenue at the velocity of sound, but many New Yorkers would be very happy if they could always be sure of doing so at the speed of a stagecoach.

In the realm of slow speeds and short distances, I would suggest that the best personal transport vehicle man has ever possessed is the horse. It is self-steering, self-reproducing, never goes out of style -- and only a double-decker bus gives a comparable view of the scenery. I admit that there are some disadvantages: horses consume fuel even when not in use, are prone to embarrassing behavior and are not really very bright. But these are not fundamental limitations, for one day we shall be able to increase the intelligence of our domestic animals, or evolve wholly new ones with much higher I.Q.s than any existing now.

When this happens, much of the short-range transport -- at least in rural areas -- may once again be nonmechanical, though not necessarily equine. The horse may not turn out to be the best choice in the long run; something like a "compact" elephant might be preferable, because of its dexterity. (It is the only quadruped that can carry out delicate handling operations while remaining a quadruped.) In any event it should be herbivorous; carnivores are much too expensive to feed. and might take a fancy to their riders.

What I am suggesting is an animal large enough to carry a man at a fair speed, and intelligent enough to forage for itself without creating a nuisance or getting lost. It would report for duty at regular times or when summoned over a radio command circuit, and it could carry out many simple errands by itself, without direct human supervision. It seems to me that there would be quite a demand for such a creature; and where there is a demand, eventually there is a supply.

Turning from this biological wishful thinking back to the world of machinery, the only novel item in the short-range category is the conveyor. By this I mean all continuously moving systems such as escalators or the "moving ways" described by H. G. Wells in The Sleeper Awakes. The layout of a conveyor belt city would be somewhat dull and mechanical, for obvious engineering reasons, though it need not be as monotonously rectilinear as Manhattan. I suspect that the greatest difficulties in the way of its realization would not be technical nor economic, but social. The idea of free public transport, though it makes good common sense, will be anathema to a great many people. Already I can picture the violent campaign the unions would launch in favor of rugged individualism, against the horrors of socialized transportation.

Yet it is becoming obvious that vehicles -- except public-utility ones -- cannot be permitted much longer in urban areas. We have taken some time to face this fact; more than 2000 years have passed since increasing traffic congestion in Rome compelled Julius Caesar to ban all wheeled vehicles during the hours of daylight, and the situation has become slightly worse since 46 B.C. If private cars are to continue to operate inside the cities, we shall have to put all the buildings on stilts so that the entire ground area can be used for highways and parking lots -- and even this may not solve the problem.

Though it seems unlikely that pedestrian conveyors will ever be used except over short distances, there is some possibility that they may have wider applications. About 20 years ago, in a short story The Roads Must Roll, Robert Heinlein suggested that travel even over considerable distances would one day be based on the conveyor-belt system -- if only because the mounting carnage of the gasoline war rules out the continued use of automobiles. Heinlein developed, in his usual meticulous detail, both the sociology and the technology of the Rolling Road culture. He imagined vast multistrip highways, with central express sections traveling at a hundred miles an hour, complete with dining places and rest rooms.

The engineering problems of such a system would be enormous, but not insuperable (they could hardly be compared with those overcome in the development of nuclear weapons, though the capital sums involved would be even greater). It is my own feeling, however, that the mechanical difficulties would be so serious that their solution in terms of present-day technology would not be worth the trouble; Heinlein himself was careful to point out what might happen if a high-speed belt snapped with a few thousand passengers aboard.

The fundamental problem of continuously moving pedestrian conveyors is: how do you get onto them safely? Anyone who has observed a nervous old lady hovering on the brink of an escalator will appreciate this point, and I do not think that we can expect ordinary members of the public, possibly loaded down with shopping or infants, to cope with speed differentials of over five miles an hour. This means that a large number of adjacent bands will be required if we hope to build expressways traveling at 50 or more miles an hour at their centers.

The ideal moving road would be one that had a smoothly increasing speed gradient from edge to center, so that there were no sudden jumps in velocity. But a continuous speed variation right across the road would be quite annoying; it would be impossible to stand still, for one foot would creep ahead of the other. The solution would be to have fairly wide uniform velocity bands, which might be marked by colored lighting, separated by narrow transition strips where the speed increased rapidly but smoothly.

The whole concept is so beautiful, and such an improvement on the conventional scheme of moving belts, that it will be a great pity if it turns out to be totally impossible.

On the other hand, there may be still more advanced solutions to the problem of pedestrian traffic. If we ever discover a method of controlling gravity, we will be able to produce not only levitation but guided movement in any desired direction -- up or down or horizontally.

Because our generation has already known the "weightlessness" of sea and space, we should not find completely fantastic the picture of a city full of effortlessly floating pedestrians -- if one can still call them that. It is a little hair-raising, though, to realize what vertical transportation would imply in a structure the size of the Empire State Building. There would be no elevator cages -- just plain shafts, straight up and down for a thousand feet. But to their occupants, under the influence of a gravity field that had been artificially twisted through 90 degrees, they would appear to be horizontal tunnels along which they were being swept like thistledown before a gentle breeze. Only if the power failed would they come back to reality with, to put it mildly, a bump.

The motor vehicle, even if it is banned from the city, is likely to dominate the 10-100-mile range of transportation for a long time to come. Let us take a brief glance at its future. It will become much lighter -- and hence more efficient -- as materials improve. Its complicated and toxic gasoline engine (which has probably killed as many people by air pollution as by direct physical impact) will be replaced by clean and silent electric motors, built into the wheels themselves and so wasting no body space. This implies, of course, the development of a really compact and lightweight method of storing or producing electricity, much better than our present clumsy batteries. Such an invention has been overdue for about 50 years; it may be made possible either through improvements in fuel cells or as a by-product of solid-state physics.

These improvements, however, will be much less important than the fact that the automobile of the day after tomorrow will not be driven by its owner, but by itself; indeed, it may one day be a serious offense to drive an automobile on a public highway. I should not care to say how long it will take to introduce completely computerized motoring, but dozens of techniques already developed by airlines and railroads already point the way to it. Automatic blocks, electronic road signs, radar obstacle detectors, navigational grids -- even today we can visualize the basic elements required. An automatic highway system will, of course, be fabulously expensive to install and maintain, but in the long run it will be much cheaper, in terms of time, frustration and human lives, than the present manual one.

The auto-mobile of the future will really live up to the first half of its name; you need merely tell it your destination -- by dialing a code, or perhaps even verbally -- and it will travel there by the most efficient route, after first checking with the highway information system for blockages and traffic jams. As a mere incidental, this would virtually solve the parking problem. Once your car had delivered you to the office, you could instruct it to head out of town again. It would then report for duty in the evening when summoned by radio, or at a prearranged time. This is only one of the advantages of having a built-in chauffeur.

The story of the railroads, which have served mankind so well for almost a century and a half, is now entering its final chapter. As industry becomes decentralized, as the use of coal for fuel diminishes and nuclear power enables the factories to move nearer their sources of supply, so the very need for shifting megatons of raw materials over thousands of miles will dwindle away. With it will pass the chief function of the rail-road, which has always been the moving of freight, not of passengers.

Already some young countries -- Australia, for example -- have virtually by-passed the railroad age and are building transportation systems based on highways and airlines. In a few more decades, today's Pullmans and diners and' roomettes will be as much period pieces as the Mississippi paddle boats, and will evoke equal nostalgia.

Nevertheless, by a strange paradox it is quite possible that the heroic age of railroads still lies ahead. On airless (continued on page 94) World Without Distance (continued from page 70) worlds like the Moon, Mercury and the satellites of the giant planets, alternative forms of transport may be impracticable, and the absence of atmosphere will permit very high speeds even at ground level. Such a situation almost demands railroads -- using that term to mean any system employing fixed tracks. On rugged, low-gravity worlds there is a good deal to be said for cars suspended from overhead monorails or cables, which could be slung across valleys and chasms and craters, with complete indifference to the geography below them. A century from now, the face of the Moon may be covered with such a network, linking together the pressurized cities of the first extraterrestrial colony.

The end of the freight-carrying ships -- the tramps and the windjammers and the galleons and the quinqueremes which for 6000 years have carried the cargoes of the world -- is already in sight; in another century, only a few will be left as picturesque survivals in out-of-the-way places. After ages without a rival, the cargo ship is now challenged simultaneously on several fronts.

One challenge is from below the water. The submarine is a much more efficient vehicle than the surface ship, which wastes much of its energy on the production of waves. With the advent of nuclear energy, the high-speed, long-range submarine envisaged years ago by Jules Verne is at last practical, but so far has been developed only for military purposes. Whether the heavy initial cost, and the problems of underwater operation, will make the cargo submarine economical is another question.

The nemesis of the oceangoing freighter may not be the submarine, however, but the Ground Effect Machine, riding on a cushion of air over land and sea. In fact, the GEM may be the biggest thing in transport since the wheel was invented 6000 years ago.

How do we ride on a cushion of air? We need a reasonably flat surface and a slightly hollowed plate lying on top of it. If we blow into the plate with sufficient force, it will rise until the air spills out around the rim; and it will float above the ground, or the water. The bigger we make our "hovership," the higher it will ride off the surface below, and the rougher the terrain it can cross. For the first time it allows us to float really heavy loads in the air; since the efficiency of a GEM increases with size, there is no reason why hover-ships as large as today's oceangoing liners should not be built, if it proves desirable.

Probably it will not, for these vehicles would be so fast (cruising at one or two hundred miles an hour) that their cargo-carrying capacity would be equal to that of a conventional ship several times larger. And, as they could travel just as easily over land as over water, they could ignore all seaports and discharge their loads a thousand miles inland. The revolution in transport that they would bring about is so great that it would leave unchanged very few of today's trade routes, wipe out the Suez and Panama Canals, open up now-inaccessible areas of the globe and completely alter the pattern of world politics.

Though the GEM may liberate us from the tyranny of roads and enable us to move with a new degree of freedom over the face of the Earth, it has several disadvantages, some of which may be fundamental. It is noisy, stirs up clouds of dust or spray, can travel only across fairly level surfaces and can never rise more than a few feet from the ground. It will both exhilarate and tantalize us, for it will hint of better things to come.

It is in the air, and above it, at altitudes of somewhat more than a few feet from the ground, that we can look for the most revolutionary advances in the future of transport. One of them lies immediately ahead, in the perfection of VTOL (Vertical Takeoff and Landing) aircraft. Though the helicopter, for all its importance in more specialized fields, has had little effect on public transportation, this will not be true of its successors, the short and medium-range air buses of the near future. What form they will take, and what principle they will operate on, no one can foresee at the moment; but no one has any doubts that practical versions will soon be developed from one or another of the horrid-looking devices that are now laboriously heaving themselves off the ground with the aid of jets, rotors or tilting wings. We shall not have conquered the air until we can go straight up and come straight down -- as slowly as we please.

As far as intercontinental transportation is concerned, the battle is already over, the decision already made. Where speed is required, the airlines have no competition. Indeed, the ridiculous situation has now been reached where traveling to and from the airport, and getting through the Paper Curtains at either end, take longer than a transatlantic flight.

Nevertheless, aircraft speeds will increase very substantially over the next few decades. Undoubtedly we shall be able, within the next generation, to build "conventional" jet transports operating at speeds of one to two thousand miles an hour. This would mean that no journey on Earth could last for more than six hours, and very few would be of over two or three hours' duration. A worldwide pattern of long-distance mass transportation might develop, far more like today's bus and rail services than anything now offered by the airlines.

For ultra high-speed services, at several thousand miles an hour, it will be necessary to use rockets, and it seems unlikely that these can ever be economical on the basis of chemical propellants. Although we can now shoot a man around the world in 90 minutes, about a hundred tons of fuel have to be burned to do so. Even when rockets are fully developed, it is doubtful if the figure could be reduced to less than 10 tons per passenger. This is some 20 times the already impressive half-ton of kerosene per passenger consumed by the big jets of today on long-distance flight. (Of course, the rocket has to carry its oxygen as well -- the penalty it must pay for traveling outside the atmosphere.)

There are two lines of development that might make very high-speed transportation an economic possibility. The first is a cheap, safe and clean nuclear propulsion system, which would greatly reduce the propellent load. Such a system is far beyond sight at the moment, because it could not be based upon fission -- the only means currently available for releasing the energy of the atom. At the risk of making myself appear a reactionary old fogy, I do not believe that uranium- and plutonium-fueled devices should be allowed off the ground. Aircraft (here is a daring prediction) will always crash; it is bad enough to be sprayed by burning kerosene, but such disasters are at least local and temporary. Fallout is neither.

The only mobile nuclear power plants that can be tolerated in the air and nearby space must be free from radioactivity. We cannot build such systems at the moment, but we may be able to do so when we have achieved controlled thermonuclear reactions. Then, with a few pounds of lithium and heavy hydrogen as fuel, we will be able to fly substantial payloads round the world at up to orbital speed -- 18,000 miles an hour.

It has also been suggested -- and this is one of those ideas that sounds much too good to be true -- that fuelless aircraft may be developed which can fly indefinitely in the upper atmosphere, powered by the natural sources of energy that exist there. These sources have already been tapped in a number of spectacular experiments. When sodium vapor is discharged from a rocket at the correct altitude, it triggers a reaction between the electrified atoms which lie on the boundaries between air and space. As a result, a visible glow may spread across many miles of the sky. It is the energy of sunlight, which is collected by the atoms during the day and released when it receives the right stimulus.

Unfortunately, although the total amount of energy stored in the upper atmosphere is very large, it is also very dilute. Enormous volumes of rarefied gas would have to be collected and processed to give any useful result. If some kind of high-speed ramjet could scoop up the thin air, and release enough of its energy in the form of heat to produce and adequate thrust, then it could fly forever with not expenditure of fuel. At the moment this seems unlikely, for the drag of the air scoops would be much greater than the thrust that could be expected, but the idea should not be much be dismissed out of hand. A few decades ago we had no idea that such energy sources existed; there may be still more powerful ones yet to be discovered.

However, even if fuel were free and unlimited, there would still be obstacles at very high flight speeds. Circus performers can tolerate being shot from cannon, but paying passengers object to high accelerations -- and those are inevitable if we hope to attain really high speeds.

Let us look at a few figures. An acceleration of 1 g means that in each second speed is increasing at the rate of 22 miles per hour. At this rate it would take almost 14 minutes to reach orbiting speed (18,000 mph), and during the whole of that time every passenger would feel that he had another man sitting on his lap. Then (on the longest possible flight, half the circumference of the Earth) there would be 20 minutes of completely weightless flight which would probably be even more disconcerting. And after that, another 14-minute, 1-g period, while the speed was being reduced to zero. At no time during the trip could anyone claim to be comfortable, and for the weightless portion of the fight even the famous paper bag would be unusable. It might not be unfair to say that in round-the-world satellite transportation, half the time the toilet is out of reach, and the other half of the time it is out of order.

A close satellite orbit represents a kind of natural speed limit for travel round the Earth; once a body is established in it, it circles effortlessly at 18,000 mph, taking about 90 minutes per revolution. If you travel faster than 18,000 miles an hour, you must provide an additional downward force to keep yourself in orbit; Earth alone cannot do it. A situation thus arises -- which the pioneers of aviation could scarcely have imagined when they were struggling to get off the ground -- when a flying machine has to be held down to keep it at the correct altitude; without some tethering force, it will fly off into space, like a stone from a sling.

In the case of a vehicle circling the Earth at 25,000 mph, the extra force needed to keep it in orbit amounts to exactly one gravity. This might be provided by rockets driving the spacecraft toward the center of the Earth with an acceleration of 1 g. Yet it would get no closer, and the only difference between this powered trajectory and a normal free satellite orbit is that it would be quicker -- one hour instead of 90 minutes -- and that the occupants of the vehicle would no longer be weightless. They would, in fact, appear to have their ordinary weight, but its direction would be reversed. "Down" would be toward the stars; Earth would be hanging above the anxious astronauts, spinning on its axis every 60 minutes.

At greater speeds, still larger forces would have to be employed to keep the vehicle in its artificial orbit. Although there seems no possible use for such performances, which would require enormous amounts of energy, man's love of record breaking will presumably lead to ultrahigh-speed circuits of the globe as soon as they become technically feasible. Going round the world in less than 30 minutes would be a rugged proposition, as well as an expensive one. To do it in 15 minutes -- at 100,000 mph -- 30 gravities would have to be endured; this might be possible, if the occupant -- who would not take much active interest in the proceedings, anyway -- was totally immersed in water. I suggest, however, that such a performance would already have passed the limit of sanity. It is impracticable to make hairpin turns round an astronomical pinpoint like the Earth. Though men will travel round the world comfortably in 80 minutes, they will never do so in eight, with any means of propulsion known today.

That last clause is not just a cautious afterthought. One day, I suggest, we will have methods of propulsion fundamentally different from any that have ever existed in the past. All known vehicles, without exception, accelerate their occupants by giving them a physical push which they feel through their boots or the seats of their pants. This is true of oxcarts and bicycles, of automobiles and rockets. That it need not always be true is suggested by the curious behavior of gravitational fields.

When you fall freely under Earth's gravity, you are increasing speed at the rate of 22 miles per hour, every second -- but you do not feel anything at all. This would be true no matter how intense the gravity field; if you were dropped toward Jupiter, you would accelerate at 60 mph every second, for Jupiter's gravity is more than two and a half times Earth's. Near the Sun you Jupiter, you would accelerate at 60 mph every second, for Jupiter's gravity is more than two and a half times Earth's.Near the Sun you would increase speed at the rate of 600 miles an hour each second, and again you would feel no force acting upon you. There are stars -- White Dwarfs -- with gravity fields more than a thousand times as strong as Jupiter's; in the vicinity of such a star, you might add a hundred thousand miles an hour to your speed every second without the slightest discomfort -- until, of course, it was time to pull out.

The reason you would experience no sensation or physical stress when being accelerated by a gravity field of any intensity is that it would act simultaneously upon every atom of your body. There would be no push transmitted through you layer by layer from the seat or the floor of the vehicle.

You have doubtless realized where this argument is leading. If, as I have suggested above, we can ever control and direct gravity fields, this will give us far more than the ability to float around like clouds. It will enable us to accelerate in any direction, at a rate limited only by the power available, without feeling any mechanical stress or force.

Though we can manage quite well, here on Earth, without such sophisticated methods of propulsion, they will ultimately become available as a byproduct of space research. The rocket -- let us face it -- is not a practical method of getting around, as anyone who has ever stood in the open within a mile of a big static test will agree. We have to find something quieter, cleaner, more reliable -- and faster.

Men will always, I hope, be content to wander about the world at two or three miles an hour, absorbing its beauty and its mystery. But when they are not doing this, they will be in a hurry; and then they will be satisfied with nothing short of 670,615,000 miles an hour, which is the speed of light and the ultimate speed limit of the Universe.

Even this speed, of course, will be totally inadequate to meet the challenge of interstellar space, but as far as the Earth is concerned it would amount to instantaneous transportation. A light wave could circle the globe in a seventh of a second; and one day men may do the same.

There is another -- radically different -- way in which men have dreamed of instantaneous transport, or "teleportalion." The idea is very old, and is embodied in many Eastern religions. There must be millions of people alive at this moment who believe that it has already been achieved, by Yogis and other adepts, through the exercise of sheer willpower. Anyone who has seen a good display of fire-walking, as I have, must admit that the mind has almost unbelievable powers over matter -- but in the case of teleportation I beg to be skeptical.

Let us consider teleportation in terms of known and foreseeable science, not wholly unknown and hypothetical mental powers. The only approach to this problem seems to be through electronics. We have learned to send sounds and images round the world at the velocity of light, so why not solid objects -- even men?

It is important to realize that the above sentence contains a fundamental misstatement of fact, though I doubt if many readers would spot it. We don't, by radio or TV or any other means, send sounds and images anywhere. They remain at their place of origin, and there, within a fraction of a second, they perish. What we do send is information -- a description or plan which happens to be in the form of electrical waves -- from which the original sights and sounds can be re-created.

Now let us do some technological day-dreaming, following in the footsteps of a great many science-fiction writers. (Perhaps starting with Conan Doyle; see one of his lesser-known Professor Challenger stories. The Disintegration Machine, published in the 1920s.) Imagine a super-X-ray device that could scan a solid object, atom by atom, just as a TV camera scans a scene in the studio. It would produce a string of electrical impulses stating in effect: here is an atom of carbon; here a billionth of an inch farther to the right is nothing; another billionth of an inch along is an atom of oxygen -- and so on, until the entire object had been uniquely and explicitly described. Granted the possibility of such a device, it would not seem very much more difficult to reverse the process and build up, from the information transmitted, a duplicate of the original, identical with it in every way. We might call such a system a "matter transmitter," but the term would be misleading. It would no more transmit matter than a TV station transmits light; it would transmit information from which a suitable supply of unorganized matter in the receiver could be arranged into the desired form. Yet the result could be, in effect, instantaneous transportation -- or at least transportation at the speed of radio waves, which can circle the world in a seventh of a second.

The practical difficulties, however, are so gigantic that as soon as they are spelled out the whole idea seems absurd. One has only to compare the two entities involved; there is a universe of difference between a flat image of rather low definition, and a solid body with its infinite wealth and complexity of microscopic detail down to the very atoms. There are, very roughly, 5 x 1027 atoms in a human body, as compared with the 250,000 picture elements in a TV image. It takes a TV channel a 30th of a second to handle these; simple arithmetic shows that a channel of the same capacity would take about 2 x 1013, or 20,000,000,000,000 years, to transmit a "matter image" from one spot to another. It would be quicker to walk.

Though the above analysis is childishly naive (any communications engineer can think of ways of knocking five or six zeros from this figure), it does indicate the magnitude of the problem. It does not prove that it can never be done, but merely that it is far beyond the scope of today's science.

There is, however, one trend which may work against the establishment of a virtually instantaneous global transportation system. As communications improve, until all the senses -- and not merely vision and hearing -- can be projected anywhere on the face of the Earth, men will have less and less incentive to travel. This situation was envisaged more than 30 years ago by E. M. Forster in his famous short story The Machine Stops, where he pictured our remote descendants as living in single cells, scarcely ever leaving them but being able to establish instant TV contact with everyone else on Earth, wherever he might be.

In his own lifetime Forster saw TV perfected far beyond his imaginings of three decades ago, and his vision of the future may be, in its essentials, not so far from the truth. Telecommunication and transportation are opposing forces, which so far have always struck a balance. If the first should ever win, the world of Forster's story would result.

On the other hand, a transportation breakthrough like that which the rise of electronics brought to communications would lead to a world of limitless and effortless mobility. Gone would be all the barriers of distance that once sundered man from man, country from country. The transformation that the telephone has wrought in business and social life would be as nothing to that which the "teleporter" would bring to the whole of our civilization. To dismiss in a single sentence a possibility that would revolutionize (if not abolish) most of commerce and industry: imagine what would happen if we could transmit raw materials or manufactured goods instantaneously round the face of the planet! This would be billions of times less difficult, technically, than transmitting such fragile and complex entities as human beings, and I have little doubt that it will be achieved within a few centuries.

Through all the ages, man has fought against two great enemies -- Time and Space. Most of his civilization and his culture consist of his winnings in this ceaseless war. Time he may never wholly conquer, and the sheer immensity of Space may also defeat him when he has ventured more than a few light-years from the Sun. Yet on this little Earth, at least, he may one day claim a final victory.

I do not know how it will be done, and perhaps everything I have said may merely have convinced you that it is impossible. But I believe that the time will come when we can move from Pole to Pole within the throb of a single heartbeat.

It will be one of history's little jokes if, when we attain this power, we are no longer interested in using it.