by Isaac Asimov
Can this sort of thing come to pass?
Perhaps.
In the preceding pages, I have talked of world population and rate of population increase as of 1970. That is because since that date the rate of increase seems to have slowed. Governments have increasingly come to realize the enormous danger of overpopulation and are increasingly aware that no problem can be solved as long as the population problem is not. Increasingly, population planning is encouraged, and China (which, with its 1-billion population represents nearly one-quarter of the world’s people) is, at the moment, strongly pushing the one-child family.
The result is that the world population increase has declined from 2 percent in 1970 to an estimated 1.6 percent in the early 1980s. To be sure, the world population has increased to 4,500,000,000 by now, so that a 1.6 percent increase represents 72,000,000 additional people each year—if anything, a trifle more than the yearly increment in 1970. We have not moved far enough, in other words; but we are moving in the right direction.
What’s more, we are witnessing a steady strengthening of feminism. Women realize the importance of taking an equal role in every facet of living and are increasingly determined to do so. The importance of this development (aside from the simple justice of it) is that women engaged in the work of the world will find other ways of reaching self-fulfillment than in their traditional roles of baby machine and household drudge, and the birth rate is more likely to stay low.
To be sure, the movement in the direction of population control, essential though it would seem to anyone capable of a moment’s thought, is not without its opponents. In the United States, an active group opposes not only abortion but also the kind of sex education in schools and the availability of contraceptive devices that would make abortion unnecessary. The only way of legitimately lowering the birth rate, in their view, is by sexual abstention, something that no sane person would suppose that people can be talked into. This group calls itself the “Right to Life,” but a better name for people who do not recognize the dangers of overpopulation would be the “Right to Fatal Stupidity.”
Then, too, in 1973, the Arab nations, which control most of the world’s oil supply, effected a temporary oil blockade to punish Western nations which, in their view, were supporting Israel. This policy, and the several years thereafter when the price of oil was steadily increased, served to convince the industrial nations of the absolute necessity of energy conservation. If this policy continues—and if to it is added a resolute determination to replace the fossil fuels, as far as possible, with solar power, nuclear fusion, and renewable energy sources—we will have taken a giant step toward survival.
There is also increasing concern over the quality of the environment. In the United States, the administration of Ronald Reagan, which came into power in 1981, put into action many programs that favor business over the humanitarian ideals that had been practiced since the days of Franklin D. Roosevelt’s “New Deal” a half-century before. In this, the Reagan administration felt it had the support of the majority of the American people. However, when the Environmental Protection Agency was put into the hands of those who felt that profits for a few were worth the poisoning of many, there arose a howl of protest that forced a reorganization of the body and an admission that the Reagan administration had “misread its mandate.”
Nor ought we to underestimate the effect of advancing technology. There is, for instance, the revolution in communications. The proliferation of communications satellites may make it possible in the near future for every person to be within reach of every other person. Underdeveloped nations can leapfrog over the earlier communications networks’ necessity of involving large capital investments and move directly into a world in which everyone has a personal television station, so to speak, for receipt and emission of messages.
The world will become so much smaller as to resemble in social structure a kind of neighborhood village. (Indeed, the phrase global village has come into use to describe the new situation.) Education can penetrate every corner of the global village with the ubiquity of television. The new generation of every underdeveloped nation may grow up learning about modern agricultural methods, about the proper use of fertilizers and pesticides, and about the techniques of birth control.
There may even be, for the first time in Earth’s history, a tendency toward decentralization. With ubiquitous television making all parts of the world equally accessible to business conferences and libraries and cultural programs, there will be less need to conglomerate everything into a large, decaying mass.
Computers and robots (which will be discussed in the next chapter) may also have a salutary effect.
Who knows, then? Catastrophe seems to have the edge, but the race for salvation is perhaps not quite over.
LIVING IN THE SEA
Assuming that the race for salvation is won; that the population levels off and a slow and humane decrease begins to take place; that an effective and sensible world government is instituted, allowing local diversity but not local murder; that the ecological structure is cared for and the earth systematically preserved—what then?
For one thing, humanity will probably continue to extend its range. Beginning as a primitive hominid in east Africa—at first perhaps no more widespread or successful than the modern gorilla—hominids slowly moved outward until by 15,000 years ago Homo sapiens had colonized the entire world island (Asia, Africa, and Europe). Human beings then made the leap into the Americas, Australia, and even through the Pacific islands. By the twentieth century, the population remained thin in particularly undesirable areas—such as the Sahara, the Arabian Desert, and Greenland—but no sizable area was utterly uninhabited by humans except for Antarctica. Now scientific stations, at least, are permanently established even on that least habitable of continents.
Where next?
One possible answer is the sea. It was in the sea that life originated and where it still flourishes best in terms of sheer quantity. Every kind of land animal, except for the insects, has tried the experiment of returning to the sea for the sake of its relatively unfailing food supply and for the relative equability of the environment. Among mammals, such examples as the otter, the seal, or the whale, indicate progressive stages of readaptation to a watery environment.
Can we return to the sea, not by the excessively slow alteration of our bodies through evolutionary change, but by the rapid help of technological advance? Encased in the metal walls of submarines and bathyscaphes, human beings have penetrated the ocean to its very deepest floor.
For bare submergence, much less is required. In 1943, the French oceanographer Jacques-Ives Cousteau invented the aqualung. This device brings oxygen to a person’s lungs from a cylinder of compressed air worn on one’s back and makes possible the modern sport of scuba diving (scuba is an acryonym for “self-contained underwater-breathing apparatus”). This makes it possible for one to stay underwater for considerable periods in one’s skin, so to speak, without being encased in ships or even in enclosed suits.
Cousteau also pioneered in the construction of underwater living quarters in which people could remain submerged for even longer periods. In 1964, for instance, two men lived two days in an air-filled tent 432 feet below sea level. (One was Jon Lindbergh, son of the aviator.) At shallower depths, men have remained underwater for many weeks.
Even more dramatic is the fact that, beginning in 1961, the biologist Johannes A. Kylstra, at the University of Leyden, began to experiment with actual water-breathing in mammals. The lung and the gill act similarly, after all, except that the gill is adapted to work on lower levels of oxygenation. Kylstra made use of a water solution sufficiently like mammalian blood to avoid damaging lung tissue, and then oxygenated it heavily. He found that both mice and dogs could breathe such liquid for extended periods without apparent ill effect.
Hamsters have been kept alive under ordinary water when they were enclosed in a sheet of thin silicone rubber through which oxygen could pa
ss from water to hamster and carbon dioxide from hamster to water. The membrane was virtually an artificial gill. With such advances and still others to be expected, can human beings look forward to a future in which we can remain underwater for indefinite periods and make all the planet’s surface—land and sea—their home?
SETTLING IN SPACE
And what of outer space? Need we remain on our home planet, or can we venture to other worlds?
Once the first satellites were launched into orbit in 1957, the thought naturally arose that the dream of space travel, till then celebrated only in science-fiction stories, might become an actuality. It took only three and a half years after the launching of Sputnik I for the first step to be taken and only eight years after that first step for human beings to stand on the moon.
The space program has been expensive and has met with growing resistance from scientists who think that too much of it has been public-relations-minded and too little scientific, or who think it obscures other programs of greater scientific importance. It has also met with growing resistance from the general public, which considers it too expensive, particularly in the light of urgent sociological problems on Earth.
Nevertheless, the space program will probably continue, if only at a reduced pace; and if humanity can figure out how to spend less of its energies and resources on the suicidal folly of war, the program may even accelerate. There are plans for the establishment of space stations—in effect, large vehicles in more or less permanent orbit about the earth and capable of housing sizable numbers of men and women for extended periods—so that observations and experiments can be conducted that will presumably be of great value. Shuttle vessels, quite reusable, have been devised, work well, and are the essential preliminary to all this.
It is to be hoped that further trips to the moon will eventually result in the establishment of more or less permanent colonies there that, we may further hope, can exploit lunar resources and become independent of Earth’s day-to-day help.
In 1974, the American physicist Gerard Kitchen O’Neill suggested that a full settlement need not be made on the moon, which could be reserved as a mining station alone. Although life began on a planetary surface, it need not confine itself to one. He pointed out that large cylinders, spheres, or doughnuts could be placed in orbit and set to rotating quickly enough to produce a centrifugal effect that would hold people to the inner surface with a kind of pseudogravity.
Such settlements could be built of metal and glass, and the inside lined with soil, all from the moon. The interior could be engineered into an Earthlike environment and could be settled by 10,000 human beings or more, depending on the size. Its orbit could be in the Trojan position with respect to the earth and the moon (so that Earth, moon and settlement would be at the apices of an equilateral triangle).
There are two such positions and dozens of settlements might cluster at each. So far, neither the United States nor the Soviet Union seem to be planning such structures, but the sanguine O’Neill feels that if humanity plunged into such a project wholeheartedly, it would not be long before there were more human beings living in space than on Earth.
O’Neill’s settlements, at least at first, are planned for the lunar orbit. But can human beings penetrate beyond the moon?
In theory, there is no reason why they cannot, but flights to the next nearest world on which they can land, Mars (Venus, though closer, is too hot for a manned landing), will require flights not of days, as in the case of the moon, but of months. And for those months, they will have to take a livable environment along with them.
Human beings have already had some experience along these lines in descending into the ocean depths in submarines and vessels such as the bathyscaphe. As on those voyages, they will go into space in a bubble of air enclosed in a strong metal shell, carrying a full supply of the food, water, and other necessities they will require for the journey. But the take-off into space is complicated enormously by the problem of overcoming gravity. In the space ship, a large proportion of weight and volume must be devoted to the engine and fuel, and the possible “payload” of crew and supplies will at first be small indeed.
The food supply will have to be extremely compact: there will be no room for any indigestible constituents. The condensed, artificial food might consist of lactose, a bland vegetable oil, an appropriate mixture of amino acids, vitamins, minerals, and a dash of flavoring, the whole enclosed in a tiny carton made of edible carbohydrate. A carton containing 180 grams of solid food would suffice for one meal. Three such cartons would supply 3,000 calories. To this a gram of water per calorie (2½ to 3 liters per day per person) would have to be added; some of it might be mixed in the food to make it more palatable, increasing the size of the carton. In addition, the ship would have to carry oxygen for breathing in the amount of about 1 liter (1,150 grams) of oxygen in liquid form per day per person.
Thus the daily requirement for each person would be 540 grams of dry food,
2,700 grams of water, and 1,150 grams of oxygen. Total, 4,390 grams, or roughly 9½ pounds. Imagine a trip to the moon, then, taking one week each way and allowing two days on the moon’s surface for exploration. Each person on the ship would require about 150 pounds of food, water, and oxygen. This can probably be managed at present levels of technology.
For an expedition to Mars and back, the requirements are vastly greater. Such an expedition might well take two and a half years, allowing for a wait on Mars for a favorable phase of the planetary orbital positions to start the return trip. On the basis I have just described, such a trip would call for about 5 tons of food, water, and oxygen per person. To transport such a supply in a space ship is, under present technological conditions, unthinkable.
The only reasonable solution for a long trip is to make the space ship self-sufficient, in the same sense that the earth, itself a massive “ship” traveling through space, is self-sufficient. The food, water, and air taken along to start with would have to be endlessly reused by recycling the wastes.
Such closed systems have already been constructed in theory. The recycling of wastes sounds unpleasant, but this is, after all, the process that maintains life on the earth. Chemical filters on the ship could collect the carbon dioxide and water vapor exhaled by the crew members; urea, salt, and water could be recovered by distillation and other processes from urine and feces; the dry fecal residue could be sterilized of bacteria by ultraviolet light and, along with the carbon dioxide and water, could then be fed to algae growing in tanks. By photosynthesis, the algae would convert the carbon dioxide and nitrogenous compounds of the feces to organic food, plus oxygen, for the crew. The only thing that would be required from outside the system is energy for the various processes, including photosynthesis, and this could be supplied by the sun.
It has been estimated that as little as 250 pounds of algae per person could take care of the crew’s food and oxygen needs for an indefinite period. Adding the weight of the necessary processing equipment, the total weight of supplies per man would be perhaps 350 pounds, certainly no more than 1,000 pounds. Studies have also been made with systems in which hydrogen-using bacteria are employed. These do not require light, merely hydrogen which can be obtained through the electrolysis of water. The efficiency of such systems is much higher, according to the report, than that of photosynthesizing organisms.
Aside from supply problems, there is that of prolonged weightlessness. Astronauts have survived half a year of continuous weightlessness without permanent harm, but there have been enough minor disturbances to make prolonged weightlessness a disturbing factor. Fortunately, there are ways to counteract it. A slow rotation of the space vehicle, for instance, could produce the sensation of weight by virtue of the centrifugal force, acting like the force of gravity.
More serious and less easily countered are the hazards of high acceleration and sudden deceleration, which space travelers will inevitably encounter in taking off and landing on rocket Rights.
The
normal force of gravity at the earth’s surface is called 1 g. Weightlessness is 0 g. An acceleration (or deceleration) that doubles the body’s weight is 2 g, a force tripling the weight is 3 g, and so on.
The body’s position during acceleration makes a big difference. If you are accelerated head first (or decelerated feet first), the blood rushes away from your head. At a high enough acceleration (say 6 g for 5 seconds), this means blackout. On the other hand, if you are accelerated feet first (called negative acceleration, as opposed to the positive headfirst acceleration), the blood rushes to your head. This is more dangerous, because the heightened pressure may burst blood vessels in the eyes or the brain. The investigators of acceleration call it redout. An acceleration of 2½g for 10 seconds is enough to damage some of the vessels.
By far the easiest to tolerate is transverse acceleration—that is, with the force applied at right angles to the long axis of the body, as in a sitting position. Men have withstood transverse accelerations as high as 10 g for more than 2 minutes in a centrifuge without losing consciousness.
For shorter periods the tolerances are much higher. Astounding records in sustaining high g decelerations were made by Colonel John Paul Stapp and other volunteers on the sled track of the Holloman Air Force Base in New Mexico. On his famous ride of 10 December 1954, Stapp took a deceleration of 25 g for about a second. His sled was brought to a full stop from a speed of more than 600 miles per hour in just 1.4 seconds. This, it was estimated, amounted to driving an automobile into a brick wall at 120 miles per hour!