Now let's take another look. Does it matter if I have a hemoglobin molecule here and I pull out this aspartic acid and I put in a glutamic? Does that make the molecule function less well? In most cases it doesn't. In most cases an enzyme has a so-called active site, which is generally about five amino acids long. And it's the active site that does the stuff. And the rest of the molecule is involved in folding and turning the molecule on or turning it off. And it's not a hundred places you have to explain, it's only five to get going. And 205 is an absurdly small number, only about 3 million. Those experiments are done in one ocean between now and next Tuesday. Now, remember what it is we're trying to do: We're not trying to make a human being from scratch, to have all the molecules of a human being fall simultaneously together in a primitive ocean and then have someone swim out of the water. That's not what we're asking for. What we're asking for is something that gets life going, so this enormously powerful sieve of Darwinian natural selection can start pulling out the natural experiments that work and encouraging them, and neglecting the cases that don't work.
So it turns out here, as in some of the arguments I was talking about yesterday, there is an important point that is left out in these apparent deductions of divine intervention by looking at the natural world. A very dramatic, strong statement of this sort has been made by the astronomers Fred Hoyle and N. C. Wick-ramasinghe. And their phrase, after a calculation in this spirit, goes something like this:
They say it is no more likely that the origin of life could occur spontaneously by molecular interaction in the primitive ocean than that a Boeing 747 would be spontaneously assembled when a whirlwind passed over a junkyard. That's a vivid image. It's also a very useful image, because, of course, the Boeing 747 did not spring full- blown into the world of aviation; it is the end product of a long evolutionary sequence, which, as you know, goes back to the DC-3 and so on until you get to the Wright biplane. Now, the Wright biplane does look as if it were spontaneously assembled by a whirlwind in a junkyard. And while I don't mean to criticize the brilliant achievement of the Wright brothers, as long as you remember that there is this evolutionary history, it's a lot easier to understand the origin of the first example.
I want to close on a beautiful little piece of poetry written by a woman in rural Arkansas. Her name is Lillie Emery, and she is not a professional poet, but she writes for herself and she has written to me. And one of her poems has the following lines in it:
My kind didn't really slither out of a tidal pool, did we? God, I need to believe you created me: we are so small down here.
I think there is a very general truth that Lillie Emery expresses in this poem. I believe everyone on some level recognizes that feeling. And yet, and yet, if we are merely matter intricately assembled, is this really demeaning? If there's nothing in here but atoms, does that make us less or does that make matter more?
Four
• Yiddish proverb •
If there is as a continuum from self-reproducing molecules, such as DNA, to microbes, and an evolutionary sequence continuum from microbes to humans, why should we imagine that continuum to stop at humans? Why should there be an open-ended gap in the spectrum of beings? And isn't it a little suspicious that the gap would begin with us?
It's of interest to me that our language has not really any appropriate terms for such beings. The theological languages have terms like angels and demigods and seraphim and so on. Even here it's interesting that the theological expectations of beings superior to humans generally represent a hierarchy of power but not of intelligence. And here again I think it is clear that we have imposed human values onto the universe. Certainly on this planet it is not apparent that there are beings more intelligent than humans, although a case can be made for dolphins and whales, and in fact if humans succeed in destroying themselves with nuclear weapons, a case could be made that
I would like to describe a famous case of the search for extraterrestrial intelligence-the search for beings more advanced than we-a case that failed. I want to explore why it failed, what lessons we can learn from this failure, and then move on to the modern search for extraterrestrial intelligence. I hope to stress where we have to be extremely careful, where we must demand the most stringent and rigorous standards of evidence precisely because we have profound emotional investments in the answer. Later I will attempt to use those skeptical strictures to apply more directly to the more conventional God hypothesis.
I suppose an equally good epigram for this subject is the following sentence said by John Adams, second president of the United States, but long before he was that. As a lawyer and advocate, he argued in defense of the British soldiers who were being tried at the Boston Massacre trials in December 1770. And he did this not because he was in favor of the British cause. He wasn't. He defended those he opposed because he believed that the truth should be pursued above all other considerations. He said, 'Facts are stubborn things; and whatever may be our wishes, our inclinations, or the dictates of our passions, they cannot alter the state of facts and evidence.' Well, sometimes they can, but we hope they can't.
The year is 1877, let us imagine. The motion of the Earth around the Sun and Mars around the Sun has brought Mars and the Earth close together, as they tend to be at intervals of roughly seventeen years.
An Italian astronomer named Giovanni Schiaparelli, looking through a newly completed and fairly large aperture telescope in Italy, was glancing at Mars and suddenly saw the surface of the planet reveal a profusion of intricate, fine, linear detail that a later observer described as being like the lines in a fine steel etching. Schiaparelli promptly called these lines
Lowell was convinced that Schiaparelli was right, that the planet was covered by a network of intersecting single and double straight lines, that these lines passed over enormous distances and therefore could correspond only to engineering works on the most massive imaginable scale. Other observers also found the canals; that is, drew them. Photographing them was much more difficult. The argument was that atmospheric 'seeing' was unreliable, due to the intrinsic turbulence and unsteadiness of the Earth's atmosphere, which generally prevent you from seeing the canals. But every now and then, by chance, the atmosphere steadies, the turbulent eddies of air are not in your line of sight to Mars, and just for a moment you can see the planet as it truly is with this network of straight lines. And then another bit of atmospheric turbulence comes by and the planetary image becomes shimmery and the details are lost. Lowell reasoned that a photograph, which involves a time exposure that adds up the rare moments of good seeing with the much more plentiful moments of bad seeing, would not reveal the canals. But the human eye can remember those instants of excellent seeing and reject the other moments, much more common, when the image is fading and blurring and distorting. And this is why, he argued, experienced observers skilled in drawing what they see at the telescope could obtain results that the photographic emulsion could not.
There were other astronomers who, for the life of them, couldn't see the straight lines, but there was a range of explanations: They were not in the best sites for their telescopes. They were not experienced observers. They were not adequate draftsmen. They were biased against the idea of canals on Mars.
Lowell and Schiaparelli were by no means the only astronomers who could find the canals. Astronomers all over the world saw them, drew them, mapped them, named them. And there were literally hundreds of individual canals
