‘We are speaking always of two forms of life, what we might call the lowest possible level of reproductive existence and sentient beings who might be much like ourselves. Let’s keep those two goals constantly in mind.
‘We start with certain demonstrated knowledge that our predecessor investigators could not have had. We know there is no kind of life of either category on the Moon. We suspect the same of Mars. We have good reason to believe that sentient life exists nowhere in the planetary system and certainly not on the Sun. It is highly probable that even the lowest imaginable forms do not exist on planets like Jupiter, Saturn and Uranus. So let’s not have any serious proposals regarding humanoids coming at us from Mars or Jupiter. They’re not there and probably never were.
‘That throws us into our Galaxy and out into the other galaxies, and to keep our thinking in focus I have prepared this simple sheet, which I hope you will keep with you during our discussion. It lists twenty stars and other celestial objects, and indicates rather nicely, I believe, the specific problems we face in either traveling to those distant objects or exchanging messages with them. Please, please, as we conduct our discussions, keep these data in mind.’
The sheet he distributed was arranged in neat columns, as any work he did would be, and it contained startling information. Six of the more interesting targets were:
In presenting the table he apologized to his science colleagues: ‘I very much wanted to give these big numbers as powers of 10, but I was afraid this might prove difficult for our many lay participants. To acquaint them with the proper system, the star Altair, a member of our Galaxy, is 9.385 × 1013 miles distant, which is read 9 plus thirteen additional digits, most of them zeros.
‘Because Professor Pope is with us, I’ve started with the star Altair, a name he made famous during his solitary ride. If you can get hold of an old Apollo, John, you can travel to your favorite star in 428,000 years, one way. And when you get there you can tell us about it, but your radio message will require 16 years to reach us, but even so, you’re lots better off than I am. As those of you who have worked with me know, I have for some years been enamored of NGC-4565, and if I send a message there right now, you and I will have to wait 40,000,000 years for a reply. So let’s not talk glibly about easy trips or quick message exchanges with celestial objects—’
‘Unless,’ one of the younger men interrupted, ‘we travel by time warp.’
‘Exactly! We’ll discuss that tomorrow,’ Mott said.
A NASA man laid out the conventional wisdom: ‘Our Galaxy contains about four hundred billion stars. There appear to be something like one hundred billion other galaxies besides our own. That means that we may have as many as four followed by twenty-two zeros of stars around us. And each of those stars could have nine planets accompanying it, the way our Sun does, which would make thirty-six plus twenty-two zeros of planets, and if each planet had a dozen or more moons like Jupiter and Saturn, we have a fantastic number of locations on which extraterrestrial life might exist. But Dr. Kelly has something to say about that.’
Now came the first striking bit of speculation: ‘Suppose we look at the forty billion trillion possible stars and begin to cut away to see if we can bring this number down to an understandable figure. In a hundred stars taken at random, seventy will be double, triple or more complex. Only thirty will be single stars like our Sun. There is good reason to assume that no double star or triple can have planets, for the close passage of such masses would quickly destroy any planets. So right at the start we cut our number of possibles by seventy percent.
‘I want to call your attention to a remarkable analysis by Michael Hart, which I’ve mimeographed for you. Hart shows that if the Earth had been only a little closer to the Sun, a greenhouse effect would have occurred four billion years ago which would have made life as we know it impossible. And if the Earth had been only one million miles farther away from the Sun, runaway glaciation would have frozen the world shut. So we see that accurate placement of the planets we’re looking for is also of vital importance.’
‘Sir,’ came a strong voice from one side of the conference hall; it was Reverend Strabismus in the first of his many interruptions. ‘Why are you surprised at the accurate placement of our Earth? Surely God intended it to be exactly where it is. He took all your calculations into consideration.’
‘Some agency certainly did,’ the speaker said without halting in his explanation, ‘and unless a similar accuracy was exhibited in placing all the other planets we’re to discuss, life of any kind might be impossible.’
‘Life would be possible anywhere if God willed it,’ Strabismus said and sat down.
The speaker used half a dozen criteria with which to whittle away that huge number of forty billion trillion, and in the end he had his remaining number so small that he ended with a brief statement which awed his listeners: ‘The factors which operate against billions of possible sites for human habitation are so tremendous that I could be persuaded that Earth is so astonishingly peculiar that sentient life has developed only here.’
‘That’s what we’ve been saying since the Book of Genesis,’ Strabismus said.
‘There’s a minority report on that,’ came a stern voice from the rear. ‘I give my paper tomorrow at eleven.’
Mott now called on a man from Cal Tech, who developed an amazing theme, one which shone like a light in a dark valley once it was enunciated: ‘We shall be talking about enormous spans of time, and it’s essential that we keep one fact in mind. No matter how many or how few other civilizations we postulate, they must be scattered at random over vast ages. It is extremely unlikely that if a planet like ours exists in Andromeda, and has developed sentient beings somewhat like us—’
‘They will be like us,’ Strabismus interrupted, ‘for they will have been made in the image of God.’
‘It’s extremely unlikely,’ the man from Cal Tech continued, ‘that they will be at the same cultural level as we are. The laws of chance dictate that they will be everywhere else. Perhaps they matured a billion years ago and are now in sad decline, unable to communicate even with themselves. Perhaps they’re just beginning and won’t develop radio communication for another four billion years. It took us that long. So in everything we do during these next weeks we must visualize a situation like this.’ And he covered the board with a series of vertical chalk lines, some near the top, some toward the bottom, but almost none overlapping. It was like a forest of telephone poles scattered upright in the sky, each in its own ambience, each at a different height, unrelated to the others.
‘Here’s an inhabited planet in Andromeda, way up here on the scale. Here we are down here in the first blush of morning. Gentlemen, remember that although this Earth has existed for about four and a half billion years, and human beings for a few million, we’ve been able to send comprehensible signals into space for only about forty-five years. Suppose Andromeda had wanted to communicate with us two billion years ago. There was no one here to listen, and even a hundred years ago when people were here, they hadn’t mastered the techniques of listening.’
The concept was so challenging, and so concisely presented, that Reverend Strabismus asked quietly, ‘We know that the universe could not have existed in the time period you suggest. The Bible explains all that. But do you think, Professor, that even today the kind of imbalance you suggest—one civilization up here, one down there, with no chance of communication—could that exist right now?’
‘I’m convinced it does.’
‘Thank you for making something clear which was not clear before.’
‘I’m not sure the various applications are clear to me,’ the Cal Tech man said.
With these conservative caveats the first day ended, and dinner was spent in furious discussion, with younger scientists warning that on the morrow they were going to tear the place apart with some contemporary thinking; these cowboys of outer space held a rump session starting at ten-thirty that night to lay plans for the pres
entations they would make regarding the future of space communication, when their radical new procedures would be applied.
The second day started like a typhoon in the Pacific, building intensity with each hour until entire island structures were endangered. A delightfully brash young man from MIT said, ‘I want you to disregard all the frightening statistics Dr. Mott handed you yesterday in his golden sheet, because he refused to take into account time dilation. For you non-scientists that’s a major consequence of Einstein’s Theory of Relativity. It means this. That time aboard the spacecraft is radically different from time as seen by those who remain behind on Earth. If Professor Pope, whom Dr. Mott mentioned yesterday, should want to fly to the nebula in Orion, it would take him only thirty years of elapsed time, but the people on Earth would have spent thirty-one hundred years.’
Mott heard two science-fiction writers: ‘We explained all that forty years ago. They’re just catching up.’
Another main speaker said, ‘I visualize travel by as many as four hundred persons in a single spaceship that accelerates to the speed of light within one hour, then moves into a time warp that will enable the crew to take the ship to any spot within the Galaxy within a mortal lifetime.’
‘How soon do you think such travel possible?’
‘By the year 2050, but incoming voyagers from the Galaxy might get here before we leave.’
Strabismus was delighted to hear such speculation, for it reminded him of those early days his Universal Space Associates peddled little green men. ‘I was right all along,’ he muttered to himself, ‘just ahead of my time.’ His old interests awakened, he listened with acute attention as radio experts predicted that if intra-galactic communication ever did reach Earth, it would probably arrive on the 1420-1662 megahertz band: ‘This occupies the space between the spectral lines of water’s components, hydrogen and the hydroxyl radical. For that reason we call it the Water Hole, around which creatures of space will congregate socially the way animals in a prairie gather at their water hole.’
Strange, strange, Strabismus thought. If I’d settled down at either Yale or New Paltz, I could have been one of the scientists here today. I know more than any I’ve heard so far, except maybe Mott. He listened attentively as a different speaker elaborated: ‘We’ve done much work at the Water Hole already. We’ve sent thousands of messages out, and we’ve spent many hours listening with our great ears at Arecibo, and based on those solid beginnings, men like Sagan and Oliver are proposing interesting new attacks. Everything we do is based on the assumption that somewhere other intelligences are ready, perhaps even eager, to communicate with us.’
On the third day a pair of Drake’s students from Cornell
explained to the laymen in the group the frightening equation covering the probability of life on some other planet in the Galaxy:
When it was placed on the blackboard the non-scientific members groaned, but the speaker quickly explained: ‘This proves how arcane we can be. All it means is that the first N represents the number of civilizations in our Galaxy capable of communicating with us right now. That’s the figure we must have to make our discussion reasonable. The second N is a figure we seek to make our discussion practical. N* is a very large number representing all the known stars in our Galaxy. Some experts say one hundred billion, some say four. In our example I’ll take four. The next six letters with their subscripts represent fractions, with each subscript standing for a crucial word or concept. When you multiply the very large number by the six fractions, you get a constantly diminishing number of possible civilizations. First fraction: the portion of stars which have planetary systems, and we heard yesterday that this fraction must be considerably smaller than one-half, more likely one-quarter. Second fraction: the portion of planets with an ecology able to sustain life, perhaps one-half. Third fraction: the portion of the eligible planets on which life actually does develop; the biologists believe it must be almost nine-tenths. Fourth fraction: what portion of those with life develop intelligent forms? Given enough time, we think it could be one-tenth. Fifth fraction: the portion of civilizations with intelligent life which learn to communicate outwardly, maybe one-third. Sixth fraction: that gripping question we discussed yesterday, what is the longevity of a technical civilization?
‘We must evaluate this question of longevity with all the philosophical resources at our command. The only hard evidence we have is our own experience on Earth. Four and a half billion years old. Technically competent to communicate forty-five years. Likely to blow itself into extinction at any moment. So the last gloomy fraction must be 45/4,500,000,000 or 1/100,000,000. Let’s face facts and multiply our equation:
This means that among the myriad stars of our Galaxy, there are probably not more than fifteen with whom we could converse.’
When some had expressed awe at the small number, others at the fact that there might be even one other intelligent society, the speaker said dryly, ‘Of course, that’s just our own Galaxy. Since we know of one hundred billion other galaxies, there could be more than a trillion civilizations spread around out there. Enough to occupy us for a while.’
The two big fights that preoccupied the commission, one mind-expanding fun, the other so fundamental that it threatened to destroy the workshop, began on the fourth day. The first pitted the old-timers, who were pessimistic about the possibility of interstellar travel and communication, against the avid youngsters, who predicted both.
‘We have the technological principles right now to fly a spaceship into the Galaxy,’ one young man claimed.
‘Of course we do,’ a cautious old-timer agreed. ‘And have you calculated the amount of energy needed to do such a job? I have. Enough to illuminate the United States for the next fifty thousand years.’
‘We’ll devise new systems of propulsion,’ the young man said.
‘You solve every objection I bring up by a “new this” or a “new that.” ’
‘That’s how we solved the objections you made forty years ago!’
Mott took no sides in this debate, but he had always attended to the quiet sardonic guesses of salty Freeman Dyson of Princeton, and if Dyson now argued that both communication and travel might be practical sooner than some thought, he was inclined to go along, but after one evening session, when debate had sizzled, he walked alone under the Vermont stars and acknowledged that he had for some time been harboring a thought which stunned him when said aloud: ‘Perhaps we are unique. Perhaps we’re the only planet that developed life. Perhaps …’
A voice hailed him: ‘That you, Mott?’ It was Strabismus. ‘The ideas thunder at you like railway trains,’ he said.
‘That’s why we hold these sessions.’
‘Cold turkey? What’s your personal guess as to how many others there might be?’
As they walked side by side through the starry night Mott answered honestly: ‘I was just about to concede that Earth might be unique—’
‘But you didn’t?’
‘No, Strabismus. I think all our fractions were far too conservative. My calculations permit about two million societies with whom we could interact.’
They looked for a light, and when they found a lamppost Strabismus took a scrap of paper from his pocket. ‘My fractions are bigger, too. I come up with about a million.’ He folded the paper, returned it to his pocket, and said, ‘But these are figures for those in the know. The general population, it would only confuse them.’
‘And you intend to keep them confused?’
‘I intend to work with them as I find them.’
‘You mean use them.’
‘They want to be used.’
‘We’ll resume in the morning!’
Like many great conflagrations, the fundamental fight began with a fire so small that a child could have extinguished it, and when it started, no one could have foreseen its destructive potential. It centered on the fraction f1, the portion of eligible planets on which life actually develops, for what started out to be a
problem in biology quickly became a question of metaphysical and religious values. The scientist who presented the basic data used an unfortunate term; he said that life would evolve compulsively whenever the primordial soup had the right components, temperature, pressure and general surroundings, and he believed that these rules must prevail throughout the universe, so that the genesis of life was possible in billions of imagined situations.
The religionists and some of the lay observers found this phrase primordial soup wildly offensive and withdrew any conciliatory gestures they may have made during the first days of the conference. One fiery Baptist, the Reverend Hosea Kellog of the Red River Bible University, shouted, ‘Man was placed on this Earth by the personal intervention of God, as a man entire, and not as a cauldron of bubbling chemicals.’ Quickly the debate ran wild, leading to this improbable exchange:
‘Are you claiming, Reverend Kellog, that God saves only those who accept Jesus Christ? And all the rest are condemned to eternal hell?’
‘That’s what the Bible says.’
‘Does this mean that all Jews are so condemned?’
‘Especially the Jews. They had a chance to accept Jesus and they denied him. They stand condemned.’
‘And all the people in Asia who never heard of Jesus? And all those in Africa? And all the Unitarians in this country, and the non-believers?’
‘They are all condemned.’
‘And the millions who died before Christ appeared? They could never have known him. Are they, too, in everlasting hell?’
‘They are.’
Even Reverend Strabismus found such doctrine too extreme, and he surprised the assembly by refuting it: ‘My Bible preaches hope for all. I was a Jew but saw the light, and I’m convinced that God welcomes me into His heaven. But this does not mean that I condemn the other Jews in this assembly or in this nation who have not seen the true way. If God is big enough to have set in motion the kind of universe we’ve been describing, He’s big enough to find a place in it for a handful of Jews and Buddhists.’
Space: A Novel Page 91