The Science that Imitates Nature’s Mechanisms A Eur

游客2024-06-04  11

问题                          The Science that Imitates Nature’s Mechanisms
    A European industrialist not long ago became very suspicious about American purposes and intentions in certain areas of scientific research. He learned by chance that the United States was signing contracts with scientists in England, France, Italy, Germany, Belgium, Sweden, Uruguay, Chile, Argentina, Australia, and other countries, calling for research into such matters as the function of the frog’s eye and the learning ability of the octopus.
    It seemed to the industrialist that such studies could not possibly have any practical value. He seriously believed that the United States was employing the foreign scientists to do meaningless work and occupy their time, while American scientists were busy in the really important areas of science. He was unaware of the fact that the United States was spending much more money at home than abroad for similar studies.
Nature does things better than people
    Actually, the research he questioned involves a field of science so new that most people have never heard of it. Named bionics in 1960, this science is the study of living creatures, a study in search of principle applicable to engineering. Nature has operated a vast laboratory for two billion years, and bionics probes the secrets of the marvelous "special-purpose" mechanisms that have developed.
    Take the frog’s eye for example. A frog eats only live insects, and its eye instantly spots a moving fly within reach of its tongue. You can surround a frog with dead (therefore motionless) flies, and it will never know they are there.
    If we can completely understand the mechanic of the frog’s eye, we can develop a "map reading eye" for missiles and a "pattern--recognition eye" for our basic air defense system called SAGE (semi-automatic ground environment). SAGE is badly overworked. Its international network of radar "EYES" supplies a tremendous mass of unimportant details about meteorites, clouds, flights of ducks, geese, and friendly planes, and it sometimes gets confused. Until we can build a mechanical frog’s eye into SAGE, it will remain somewhat inefficient.
Military and civilian uses
    The frog’s eye holds promise in civilian life, too. For example, at most major airports the airtraffic problem--with 20 million flights per year to handle--has reached a critical stage. We must develop better devices for monitoring and controlling air traffic.
    Special-purpose mechanism as exciting as the frog’s eye can be found throughout nature. The bat is under study because the bat’s sonar is much more efficient than man-made sonar. By bouncing supersonic squeaks off objects around him, the bat flies about with remarkable skills. A bat can fly through a dark room strung with dozens of piano wires and never touch a single wire.
    The mosquito is under study because we need to solve the problem of Static that lessens the efficiency of our communications systems. A mosquito, simply by vibrating its wings, can set up a hum that will cut through any interfering noise (man or nature can create loud whistles or thunder, for instance) and give a message to another mosquito 150 feet away.
Electrical system
   Theoretically at least we should be able to copy these mechanisms found in nature, for all biological organisms-from mosquito to frog to man--are in part actually electrical systems. The sense organs that "connect" all animals to the outside world are merely transducers--instruments like a microphone, TV camera, or phonograph pickup arm--which convert one form of energy into another. A microphone, for example, converts sound into electrical signals which are carried to a loudspeaker and converted back into sound waves. Similarly, the nerve cells of a man’s ear convert a cry for help into electrical pulses which are sped over his nervous system to the brain. The brain receives the signal, and then sends an answering electrical-pulse message to his legs, where it is convened into muscular energy when he starts running toward the cry.
   We have been slow to profit from this close analogy between a biological organism and an electronic system. It was only in the early 1950’s that we consciously began to unite biologists with physicists, chemists, electronic experts, mathematicians, and engineers in a team to solve the mysteries of biological machinery. The first formal bionics meeting--called by the U. S. Ak Force--was held in 1960.  A year later there were 20,000 biologists at work in research laboratories in the United States more than double the number employed ten years earlier.
Electronic and nonelectronic
   A bionicist can, of course, copy much in nature without resorting to electronics. For example, an airplane wing that gives unique stability to a small plane was introduced by the Cessna Company in 1960; the wing tips of a seabird served as the model. An artificial gill to extract oxygen from water and throw off carbon dioxide like a fish’s gill is being studied by the Navy for use on submarines. For the Navy, too, the U. S. Rubber Company is making tests of a rubber "skin" for boats and submarine hulls, modeled on the elastic skin of a dolphin.
   But the greatest advances in bionics unquestionably will be electronic in nature. Already an instrument laboratory has developed an "eye" that can peer through a microscope and distinguish certain kinds of diseased ceils from healthy cells. General Electric Company has an experimental eye, the Visilog, that operates on the principle used by the human eye in judging distance as a solid surface is approached.
   We humans judge out rate of approach by the changed occurring in the texture of a surface as our eyes get closer and closer to it. This explains why we sometimes fail to see a glass door, but we always stop short of a brick wall. General Electric’s eye calculates the rate of approach to any textured surface and contains a device to slow the approach speed. It is being developed, hopefully, to pemit a planned moon-probe rocket to make a soft landing on the moon’s surface. A small variety of Visilog may be created for the blind.
Ears, nose, and brain
   The owl’s ears are fascinating to many bionicists, for the owl has uncanny directional hearing. He can hear a mouse chewing and fly down on it, even though it is hidden from sight under a pile of leaves. For those engaged in designing sensitive mechanic ears for listening to enemy sonar, owl research may indeed have value.
   Nor is the nose being ignored. Many male creatures find their way to their mates by following an odor given off by the female. To explore mechanical scent detection, the Armor research Foundation has developed a synthetic nose which can, it is believed, detect scents in vapors at a ratio of one particle to a million. The Foundation thinks that it can be used in early detection of food spoilage, and to warn industrial and military personnel of the presence of poisonous vapors.
   Finally, the bionicist is extremely interested in the one general mechanism that serves the entire animal kingdom--the brain. The brain makes all animals unimaginably efficient, like small-size computers. "Actually, though," says Dr. Warren S. Moculloch, one of our great computer-scientists, "computers are nothing more than stupid beasts, they haven’t the brains of
an ant. And they can’t do the job that must be done."
   Hopefully, bionicist is extremely interested in the one general mechanism that mimics the brain. But as long as the tiny brain of a pigeon continuous to baffle science, there seems little likelihood of understanding the secrets of the human brain during this century. Yet, even if the bionicist never attains this goal, he will make many discoveries that once seemed impossible to us. Even in our lifetime he may be able to build machines that will be intelligent enough. [br] The U. S. Rubber Company is making tests of modeling the elastic skin of a dolphin for _____.

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答案 boats and submarine hulls

解析 文章第十一段中提到美国橡胶公司通过模拟海豚的弹性皮肤来尝试为船只和潜水艇做橡皮船体。
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