"Thomas A. Easton - Life is in the Stars" - читать интересную книгу автора (Easton Thomas A)

LIFE IS IN THE STARS
Thomas Easton
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To the writers and readers of science fiction, life is the material of fantasy and speculation: How did it
begin? Did it just happen? Did an alien astronaut once visit Earth and leave our ancestors in his litter?
Can it be made in the laboratory? If so, what Utopian or horrifying visions might it make possible? Is it to
be found on other planets of other stars? If it is, what forms might it take? When we reach the farther
depths of space, will we meet intelligence? Will these other beings be ones whom we can love, with
whom we can talk, from whom we can learn? Or will they be the stuff of nightmares?

To the biologist and chemist, life is a phenomenon of interacting chemical reactions, and what they call a
living system is characterized, like AchillesтАЩ ship, by a continual renewal of its substance. To them, life is a
question to be studied in the laboratory, and though they cannot answer all the questions of the
science-fiction world, they can say, тАЬYes, it may be possible to make life in the laboratory,тАЭ and, тАЬLife
probably does exist on other worlds.тАЭ Indeed, J. B. S. Haldane said in October 1963, тАЬSome of us, or
of the next generation, will try to make a living organism.тАЭ He could say this because we now have a
nearly completeтАФ in principleтАФ understanding of how life first arose on Earth. We can even justify the
claim that the chemistry of the universe is such that life is inevitable wherever certain broadly defined
conditions hold.

Furthermore, this inevitable life may be much like that found on Earth. The organic compounds of which
our worldтАЩs living systems are built consist mostly of the elements carbon, hydrogen, oxygen, nitrogen,
sulfur, and phosphorus, and these organo or bioelements are among the most abundant elements in the
universe. However, while life may be expected to developтАЬ around readily available materials, this does
not imply that there is anything necessarily inevitable about тАЭlife as we know it,тАЬ based upon water and
oxygen and proteins. There must, after all, be worlds where water cannot be liquid and where the
chemistry of life would have to be fitted to some other solvent. And even here on Earth there are a few
kinds of bacteria that do not use oxygen.

What does appear to be inevitable is that wherever water can be the solvent, life will be based upon
amino acids and their polymers, the proteins, for the experiments of those chemists interested in the
problem of the origin of life have strongly indicated that, early in the -history of any watery planet with
some energy supply, proteins will be formed in large enough quantity to support the development of life.
Accordingly, we can expect that on many of the ten billion Earth-like planets estimated to lie among the
billion billion planets of the hundred billion billion stars in the observable universe there is life whose
chemical basis is similar to that of our own. And a few of these planets are bound to hold intelligent life.

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Although the source of life has been a goal and obsession of philosophy and religion as long as man has
existed, it was not so very long ago that men believed that living animals could and did arise from dirt,
slime, the sea, and rotten meat without the aid of parents. It was even thought, quite seriously, that when
a sweaty shirt was put into a closed vessel with a handful of wheat grains, the vapors combined to form
full-grown mice, and that lambs were formed within certain fruit. It was not until the Seventeenth Century
that Francesco Redi demonstrated that maggots came from fly eggs rather than from rotten meat alone
and began the debunking of the myths. Other skeptical investigators soon reduced the question of
spontaneous generation to that of microorganisms, such as bacteria and molds, ruling it out for all higher
forms of life.
In 1864, however, Louis Pasteur provided strong evidence that spontaneous generation did not occur at