The Emergence of Life and of Intelligence

[00:00:00] INTRODUCER:
Through a very generous gift of Charles M. Hitchcock, the late Charles M. Hip– Hitchcock, 65 years ago, this lecture series was established. And as those of you who’ve looked at your program noted, it was for, and to quote, “A professorship in the University of California for free lectures upon scientific and practical subjects, but not for the advantage of any religious sect nor upon political subjects.” And so I assume that, uh, Professor Hoyle will stay within the framework of the initial wis-wishes of the, uh, the donor.

Uh, this evening’s Hitchcock Lecture marks the sixty-fifth year in which distinguished scholars have presented their views to Berkeley audiences. And I’m sure that, uh, Professor Hoyle will be commenting upon some of the astronomers on this list. I might just mention the names of a few people who’ve gone through this professorship, those that might be familiar to those undergraduates here who are involved in scientific studies at the present time.

And scholars such as Thomas Hunt Morgan, Peter Debye, Robert Milligan, uh, Millikan, J.B.S. Haldane, Niels Bohr, John Northrop, Enrico Fermi, Wendell Stanley, Robert Oppenheimer, just to name a few, have been in this very distinguished, uh, chair. I believe that all have endeavored to discuss not just their technical fields, but the relationship of these technical fields to the society surrounding them and the impact that some of these discoveries in the fields in which they work have had. And in this sense, they’ve been popularizing their topic in the best sense of the term, not by descending to a puerile level, but by trying to communicate the meaning of what’s happening in various scientific areas.

Tonight, we have another illustrious name to add to this list of Hitchcock lecturers, and that is Sir Fred Hoyle. Uh, Professor Hoyle did his graduate work at Cambridge and is now from St. John’s College at Cambridge, England. He served as a university lecturer in mathematics at Cambridge from nineteen forty-five through fifty-eight.

Uh, he then became the Plumian Professor of Astronomy and Experimental Philosophy at Cambridge University, uh, in nineteen fifty-eight and remains in that position to the present time. During this period, he’s served in a number of visiting professorships in the United States and received a number of honors here. I just mentioned a few of these because the list is a very long one.

He was on– a staff member of the Mount Wilson and Palomar Observatories in nineteen fifty-six through fifty-eight. Uh, he was a visiting professor, uh, of astrophysics at, uh, Caltech and Pasadena. Uh, he’s recently been the Andrew D. White Professor at Large at Cornell University in nineteen seventy-three.

He was elected a Fellow of the Royal Society in nineteen fifty-seven, served as its vice president in nineteen seventy and seventy-one, and belongs to both the, uh, major American societies for science. That is an honorary member of the American Academy of Arts and Sciences in 1964, and is a foreign associate of the National Academy of Sciences, elected in 1969. His sci– And his– During his scientific career, he’s published a large number of papers of scientific interest, uh, great scientific interest in the fields of astronomy and astrophysics.

But perhaps of even more interest to this audience is the fact that Professor Hoyle has published rather extensively in the popular literature and occasionally published novels of considerable interest. I’ll just mention a few of these. Um, Nature of the Universe, nineteen fifty.

Decade of Decision, nineteen fifty-three. The Black Cloud, nineteen fifty-seven. Ossian’s Ride, nineteen fifty-eight, which my Irish colleagues in the English department tell me is a very fine example of an Irish myst-mystery story.

Uh, Of Men and Galaxies, 1964, Man in the Universe, 1966, Seven Steps to the Sun, 1970,

[00:04:06] PROFESSOR PARK:
Stonehenge to Modern Cosmology, 1973, and numerous other books and books in press. Uh, this evening, Professor Hoyle will lecture on the Emergence of Life and Intelligence, a title which interests me and many of my colleagues be-because we wonder just what the relationship is between those two things quite often. We all look forward to enjoying, uh, an enlightening evening, and I enjoy presenting to you Sir Fred Hoyle.

(applause and cheering)

[00:04:45] SIR FRED HOYLE:
Uh, thank you, Professor Park, for your kind introduction. You are indeed, uh, correct in drawing our attention to the many distinguished, uh, holders of the Hitchcock Professorship that is on the list at the back of your programs. And I may say how very honored I am, in– very honored indeed, to join this distinguished list.

Two of the members there were very well known to me, and I’m happy to be able to say that as a young man, I was able to count them among my most valued friends, and one was, uh, Edwin P. Hubble and the other, Walter Baade. Both were, um, very rather severe technical astronomers, um, particularly Walter, Walter Baade. And I, when I looked at their name on this list, I wondered with what sense of shock they might have thought that the next astronomer to be on the list, particularly Baade following him, would be speaking on the subject that, uh, Professor Park has referred to tonight, this mysterious subject of, uh, uh, the emergence of life and of intelligence.

Because only, uh, twenty years ago, when Baade gave his talk, this would have seemed pretty far out. Today, well, maybe it is far out still, but, um, owing to the accumulation of knowledge that has occurred over the past two or perhaps two or three decades, it no longer seems quite as far out as it formerly did. And at the end, I shall be telling you of proposals which have been very seriously worked out in great technical detail, which would have, I think, astonished, um, uh, the preceding generation, uh, just as much perhaps as the landings on the moon, uh, when they occurred would, uh, i- would have astonished people at the turn of the present century.

Now, there may be many forms of life of which we are totally unaware and of which we can only barely conceive. For example, you might speculate on the possibility of life being based on the property of nuclear matter. Life in an exceedingly dense state, something like a ton to a cubic centimeter.

But this, at our present level of knowledge, is more a matter for a science fiction story than for a lecture such as this. So what I propose to do tonight is to bypass all the strange things which might possibly exist. Rather, uh, will I seek to argue in terms that we can grapple with in, in a tolerable amount of detail.

And this implies that in just discussing the emergence of life, I’ll be meaning chemical life based on the properties of the carbon atoms. In contrast to the situation a few decades ago that I was mentioning a moment ago, uh, we believe today that we know quite a bit about the nature of this kind of life. We know that this kind of life is based on a complex of chemical reactions with substances called proteins playing a dominant role.

Now, although in dietary terms, we’re re- we- we’re required to have a daily intake of proteins in our food, it’s important to realize that we do this not for the sake of the ingested proteins themselves, but for the basic subt- substances out of which these proteins are themselves made up. What happens is the proteins we eat are first broken down into their constituents, known as amino acids, and these amino acids are then built within our own bodies into our proteins, the proteins required specifically by our kind of creature, the human being.

A dog proceeds similarly, using the same basic amino acids, but building them into the protein structures suited to itself. And so for all the animals, we all use the same basic amino acids, but we, we arrange them individually according to our separate needs. Now, how is this done?

How does each animal manage to build just what is right for itself? Nowadays, we even understand, thanks to modern biology, the answer to this crucial question, or at least a fair fraction of the answer. Each of us contains within ourselves a kind of vast chemical blueprint, which is simply copied time and time again as our kind of proteins are made in order to serve our separate bodily functions.

Now, I must, although this I’m, I’m talking biology And I shouldn’t as an astronomer, I’m going to stop now because it’s not my purpose t-tonight to develop the chemical basis of life in any real detail. What I’m concerned with in these introductory remarks is to emphasize that life is now seen to be based on a complex but well-ordered form of chemistry.

Which is to say, on the re- on the relations between various kinds of atoms. And the relations between atoms is described by physics, by methods that are well understood. Indeed, no very deep knowledge of physics, such as is required to grapple with modern problems of the inner structure of individual particles, is required in order to calculate how the atom of sodium and that of chlorine bind themselves to form the molecule of sodium chloride, the molecule of what we call common salt.

The relevant basis for such an understanding was discovered nearly fifty years ago in the work of Heisenberg and Schrödinger and in that of Wolfgang Pauli. It came already at the beginning of that revolution of physical thinking which became known as quantum mechanics. Yet although we believe we understand the basic principles on which molecules are constructed from atoms, it’s beyond our ability to calculate, starting from the basic principles, the detailed behavior of any but the simplest molecules.

It would be possible, for example, to calculate the properties of a molecule like sodium chloride and to do it with reasonable precision. But it would be quite beyond our powers to calculate the properties of a protein containing a thousand or more amino acids. The intricate maze of detail involved in such a calculation be– goes beyond our capacity, even when aided by the largest modern computers.

The world possesses a level of intricacy which we can’t remotely approach even though we believe, with good reason that we understand the principles on which the intricacy is based. All this is very odd and very interesting. By restricting ourselves to the study of very simple systems, we seem to be able to discover rules according to which the world is constructed on a much more complex scale.

Perhaps one might ask, our ability to follow through to an understanding of this more complex scale is a temporary handicap, one that will eventually be swept aside as science advances. For myself, I doubt that this will turn out to be so. I doubt that there is any simpler description of the whole universe than the universe itself.

The usual concept of the scientist that eventually he’ll be able to build a so-called model of the universe which will serve to describe with accuracy the behavior of the actual universe is, I believe, a chimera. What we can do, however, is to build models which give a satisfactory description of limited aspects of the universe. It’s when we come to demand full detail that the trouble arises.

We can manage to deal with a molecule of sodium chloride perfectly well, and in doing so, we gain insight into the general properties of proteins and of even larger biochemical structures than the proteins. But we fail in our endeavor to describe detail. In short, our brains permit us a perceptive view of the universe, but not a complete view.

Nor in my, in my opinion, will they ever permit us a complete view. Subject to this inherent limitation, it’s the purpose of my talk tonight to consider what can be said, firstly, about the emergence of life in the universe, and secondly, about the emergence of intelligence. Then by joining together what we learn about these two matters, I wish to go on at the end of my lecture to give some thought to what the outcome for life here on the Earth may turn out to be in the centuries and in the millennia that lie ahead of us.

Although I spoke of amino acids as being much less complex in their structure than proteins, and although the proteins themselves are much less complex than the remarkably long chain molecules which carry our genetic heritage, It’s important to realize that even amino acids are complex compared with the substances that life must have evolved from in the first place. There must have been molecules such as water, hydrogen cyanide, carbon dioxide, and ammonia, possibly. In fact, just the kind of molecule which astronomers have recently discovered to exist in vast quantities within the gas clouds of the Milky Way and of other galaxies.

And I’d like to show you a slide, or a few slides, uh, a series of slides, uh, emphasizing how just what the recent results have been. So could we, uh, show the, the first few slides? I’ll tell you when to stop.

This series of slides sh– uh, starts with one or two of the nearer galaxies to our own, but you must realize that, uh, there are vast numbers of galaxies, uh, way out in space, far beyond our own. Uh, and this is just one of a very, a very small number of nearby galaxies, the galaxy M33. Uh, in total, there are probably of the order of a thousand million galaxies within the range of what can be seen with a large telescope.

Could you have the next one, please? This is the, uh, another of the near, uh, another of the near galaxies. Uh, you can, with a, a reasonably practiced eye, tell that there are lots of, uh, gas and dust clouds in an object such as this, but perhaps it becomes more obvious if we nook– look at the next slide.

The next one, please. It’s pretty obvious when you look at a galaxy such as this. By the way, the, the, these things that you see around here, these are just, uh, these are just nearby stars.

It’s this thing we’re supposed to be looking at, and that’s very, very far away. I mean, some, uh, probably about ten million light-years in, in the case of this particular galaxy.

(clears throat)

So you can see that there are quite a lot of, of gas clouds, uh, uh, distributed on a vast scale throughou-throughout, uh, throughout the galaxies. When, when we look out from the interior of our own galaxy, of course we see the details of these gas clouds, And I want to show you now on the next slide, and on the next one or two slides, what these details look like. So here, uh, this is the so-called North American Nebula, and you get the idea of this.

We’re within our own galaxy now. You get an idea of the vast profusion of stars, how very many there are, and of the appearance of the, of, of the gas, glowing gas clouds, as you can see around here. The next one, please.

Here, this is the famous Horsehead, uh, Nebula. Uh, it’s standing on its head, as, uh, we’ve got it here. Uh, and again, you can see the, you can see the dust here blocking the light of stars that lie beyond it and, and then the glowing red cloud here.

The next one, please. Again, you get, um, you get the red light emitted by hydrogen atoms tending to dominate this, um… And these are the sort of, of clouds that one thinks, uh, are– stars are condensing at the present time, new stars.

The next one, please. Here, Trifid N-Nebula. Um, again, you get the impression of the dark clouds, and one, one is beginning to understand, uh, something of the constitution of these, the-these clouds and how the gas and the, the dust interrel-relate rather intimately to each other.

The next one, please. This is the, um, the famous, uh, nebula in the belt of the constellation of Orion, the Orion Nebula. And here, a-again, the gas is, is very clear from a picture such as this.

And this is just the sort of object that astronomers believe that, um, uh, stars are forming at the present time. But what has turned out in the last five years is that, uh, whereas we thought that such clouds were almost entirely very simple gases like, like hydrogen and helium, uh, mixed together with, um, with dust and with other materials like carbon, possibly in atomic form. What has e-e-emerged is that these clouds contain in large quantities, exactly the sort of molecule which it is a chemist’s dream to make into, uh, to, to, to produce life out of.

And I’m, I’m going to show you a technical table of these. So if you don’t worry about the details, but the, the, the, s-the sort of state of play, uh, is, is indicated here of the, of the molecules. Uh, many of these would not be very useful in a, in a dense condition.

Uh, this sort of molecule or that sort of molecule wouldn’t last very long. But here you’ve got ammonia, here you’ve got the hydrogen cyanide. Uh, somewhere or other we’ve got water and, and, uh, um…

Yes, here. And, um, the-these are precisely the molecules containing quite a lot of hydrogen. These are precisely the molecules that, uh, the chemists and biochemists have speculated, uh, would be just the right sort of molecule, um, with which to, to, to get to grips with the beginnings of the origin of life.

And the startling, somewhat startling thing has, has been the, the, the gradual piecing to Evid– uh, uh, piecing together of evidence, um, by very delicate modern radio techniques or in molecular wave techniques, ah, that these molecules exist in vast, vast quantities. Very well. I’ll have the, I’ll have the house lights then.

Thank you. What one can say is in, in view of this very widespread diffusion of the basic life-forming molecules everywhere in the galaxy and, and in other galaxies, one would naturally suppose that life is likely to be widespread throughout the universe. The basic physical laws which permit the chemistry of life are the same in other places.

I think I should leave that open, if you please, because we’re going to need it again. So we would rather expect that similar structures to ourselves can be expected simply because of the vast profusion of planets and stars. There are a hundred thousand million stars in our galaxy alone.

You’ve got an idea of this from looking at the very rich star fields that we saw a moment ago. And a large fraction of these hundred thousand million stars possess the characteristics which astronomers believe to be associated with the occurrence of planetary systems. In other words, there are strong reasons for thinking that a considerable fraction of the stars of our galaxy, perhaps 50% of them, possess planets moving around them.

So, in considering the emergence of life on a galactic scale, we have to think of something of the order of a hundred thousand million possible sites of a planetary type. Uh, of course, as I indicated right at the beginning, life might also arise in ways other than on planetary surfaces, in ways that we can scarcely imagine. But as I also said in the beginning, it isn’t, uh, necessary or it isn’t my concern tonight to speculate about these other possibilities.

I wish to keep as close as I can, uh, to what we know to be possible. Not all planetary systems will be suitable for the emergence of life. Among the planets of our own system, only the Earth is likely, with, uh, high probability to possess life.

Uh, let, let’s just take a glance at, uh, a few of the planets and, and compare them with the Earth. Could you have the next slide, please? Well, this is the planet Jupiter, as most of you will recognize.

And, uh, this is not, uh… It’s possible, But I think one has to go fairly far out into the realms of speculation to believe that, uh, that life is likely to exist. It’s true that, that the, that the correct form of molecule, uh, exists in the atmosphere of Jupiter.

Uh, there’s no difficulty about that. But the, the general, um, circumstances of the case, uh, don’t suggest that anything very much like life as we know it would exist in this particular case. Could I have the next slide, please?

Here you have Saturn, um, and, uh, once again, the situation is very much the situ– uh, as it, as it was for Jupiter. It’s po– it’s possible many people think that, uh, that, that life, even life based on the carbon atom, um, much in our style, might still be possible in these objects. But, uh, I s-I said, I think, with high probability, I don’t think anybody would really believe that with high probability, uh, life is likely to exist in, on Jupiter or Saturn or on Mars.

Could we have the next one, please? This is a, a photograph of Mars. All these, I should say, are, are taken from the ground with ground-based telescopes.

So you see that quite a lot can be seen even without going out into space. Uh, but for the last slide, the one of the Earth, of necessity, we have to go out into space.

(laughter)

So could we have the, the next slide, please? And this, as you can see, is so mani-manifestly different from the others as to bring home to us that had the Earth not been present in our system, had the Sun possessed eight planets without the Earth, then the solar system would very likely be sterile. And among other systems of planets, we must suppose then that some indeed will be sterile.

Could you have the lights up, please? So a quest– uh, a question that one very naturally asks is, what fraction of the total number of planetary systems, uh, is it likely to be that is sterile? But in one sense, the answer to this question is is uncertain, quite uncertain, and yet in another sense, the uncertainty is probably irrelevant to a more important question, one that we would really find more interesting, and

this and that’s this. Having allowed for all the astronomically and chemically unfavorable cases, does a large number of suitable sites for the emergence of life still remain? After all, we have a hundred thousand million possibilities to start with.

We can afford to be fairly prodigal. If only ten percent of these are astronomically suitable and only a further ten percent possess the appropriate chemistry, we still have as many as a thousand million favorite sites remaining. And it seems rather unlikely that the favorite fraction will be much less than this, much less than a thousand million favorite sites.

The first step toward the origin of life is comparatively well understood. This is a step which goes from the simple inorganic substances, uh, I don’t know, could, could we have the next slide, please? Um, I’m sorry to keep doing this and that, but…

These, these are the things that we saw exist everywhere. The first step is from these substances to building them into more complex ones. Substances containing a moderate number of atoms, say thirty to a hundred, like, rather like the amino acids.

The essential feature of this step is that it supplies a store of energy, which can then be used to drive more complex systems. The source of the energy seems as if it must come from the radiation incident on the planet from the primary star, just as, uh, everything on the Earth turns on radiation that’s incident on the Earth from the sun. Now, this first stage doesn’t seem too difficult to achieve.

And most workers, uh, who have studied this matter technically seem to have expressed little doubt that it would take place in, in quite a high proportion of all the cases. Well, so far so good. Y-yet with such an energy storage, that’s these things being built up into things like amino acids and perhaps simple sugars, we’re still very far from a synthesis of the exceedingly complex molecules on which life itself is based.

Now, much work is going on today investigating these further steps. The, the ones that must take place before the first self-replicating biological cell can arise. And until more is known about these further steps, it’s still too early to make a quantitative estimate of the probability of life emerging in a particular case.

There could be barriers requiring highly improbable circumstances which could eat into our thousand million available cases to quite a substantial degree. On the other hand, one can say it’s been the experience so far that estimates of probabilities always seem to rise, not fall, as more becomes known about the problems that are involved. This has certainly been the case on the astronomical side.

The evidence I showed you, wh-which you can actually see here concerning the molecular chemistry of dense interstellar clouds, shows the same thing on the chemical side. And my hunch would be that the same situation will arise also as more becomes known about the biological details. What at first sight seems to one incredible and unattainable becomes credible and attainable as our knowledge increases.

For this reason, I don’t think it an unreasonable speculation to suppose that life has arisen in many millions of cases, perhaps indeed in tens or even hundreds of millions of cases. And this would set the nearest planetary system to our own on which life has arisen at a distance of about a hundred light-years. Meaning that if we could exchange messages with intelligent creatures in such a system, the messages would take a few centuries to pass between us.

But this is to run quite a bit ahead of, of what I’m going to say in the rest of my talk. Let’s suppose we’ve given the first living cell. Much still remains to argue.

Particularly, much remains to argue before intelligent life can emerge. Even on the Earth, complex life forms, creatures aggregated from, uh, from out of many cells adding together were a long time in coming. Could I have the next slide, please?

(coughing)

This is a diagram, uh, illustrating the, the past history of the Earth, starting something like four thousand five hundred million years ago before the present and coming round in a circle until you arrive back at, at now. And these are the sort of creatures that have, uh, existed on the Earth over the various time spans. And you see that the, the opening, uh, of, of the drama, as it were, was consi– confined to bacteria, sing-single-cell bacteria, then followed the blue-green and then the green algae.

Uh, and then only when you come right over into this last little sector do you begin to get, uh, complex forms built out of many cells emerging. And this seems to indicate that until comparatively recently, a barrier of some kind existed on the Earth, a barrier which prevented more than single-cell bacteria, algae, and so on from existing. It’s interesting to speculate on what this barrier might have been.

I’m much impressed myself by a temperature correlation involving this, th-th-this evolution that you can see here on the slide. Strikingly, uh, the early forms of life were all high temperature forms. Bacteria can exist to the boiling point of water.

Blue-green algae, the next stage here, to about seventy-five degrees centigree– centigrade. The sort of things that, that were beginning to exist in here to about sixty degrees, suggesting that the Earth, in its early history, was too hot to permit any but simple cell creatures with highly– having highly protective cell walls from existing. Well, this idea fits this sort of data very neatly, um, it really leads to quite far-reaching astronomical consequences if, if one believes it, which are ha– which– consequences which are hard to reconcile with present-day astronomical theories.

So I just mentioned this in passing, But you can see what the evidence is for yourself. Could I have the lights up now, please? I wish to come now to the second part of my subject tonight, to the emergence of intelligent creatures.

For in a large measure, this is what we’re really interested in. On what fraction of planets, in how many of the many millions of cases can we expect not just life, but intelligence to have emerged? Indeed, our emotional attitude to life isn’t really a chemical matter at all.

Although the difference between a well-loved person being alive and being dead may turn on certain subtle chemical processes, this isn’t at all the way we feel about it. There’s something else involved. Most people who’d never dream of strangling a dog don’t hesitate to swat a mosquito.

Yet the chemistry of the mosquito is basically the same as that of the dog. The situation is that we distinguish between higher and lower animals according to the complexities of the nervous systems with which animals are endowed. I think we shall need, be needing the next slide in a moment, please.

A nervous system is basically electrical in its operation with an, with an animal being made up of two parts, which you can see here. I don’t think… Yes.

An animal is made up of a chemical part, a chemical, uh, replication plus electronics. And the more the elenic– electronic part dominates this summation that you can see here, the higher we judge the animal to be in the zoological evolutionary scale. The more the electronic system happens to match our own system, the better regarded the animal.

And indeed, among humans, the more similar the other person’s electronic system is to our own, the better regarded or the better loved the person. Similarity in the electronic part distinguishes the category of us from the category of them. And at a certain level of electronic complexity, we rather arbitrarily introduce the concept of intelligence, a level which we set a little below our own capacity.

We acknowledge a spark of intelligence in the dog, but the behavior of a cat strikes us as independent rather than intelligent. So that you see that essentially as a matter of definition, any creature endowed with a, an electronic system more complex than our own must be endowed with high intelligence. Animals aren’t regularly able to synthesize amino acids and sugars as plants do.

Animals must therefore acquire these substances is either by eating plants or by eating each other. Basically, all animals are scroungers, living on the stored chemical potentialities which others have first accumulated. It was precisely to assist in the process of scrounging that the electronic systems possessed by animals developed.

And since the better the electronic system, the better the scrounger. Biological operation, uh, biological, uh, evolution rather, has operated to increase steadily over many millions of years the level of complexity of animal electronics. And since we judge the level of an animal by the complexity of its electronics, it follows that the higher the animal, the greater the scrounger.

The electronic system in man has indeed become so subtle that our scrounging for energy in particular has now extended well beyond the eating of plants and of other animals. We scrounge extensively today on non-living materials. The discovery of fire made use of the decay products of trees as an energy source in wood.

The burning of coal and oil were further steps along the same path. Well, in the modern nuclear power plant, we’ve attained to the use of an entirely non-organic material as an energy source. This access to non-animal sources of energy has developed with increasing rapidity to a point where our modern society, um, in our modern society, we can clearly see that either some more restrained pattern of behavior must be applied in, in future years, or the evolution of our species will end itself in a catastrophic social explosion.

And it’s in these evidently crucial circumstances that we’ve begun to wonder how things may have fared with other creatures living on planets moving around other stars, and we’ve even begun to wonder about the possibility of communicating with such creatures. Interstellar communication, as we may call it, raises many problems, some technical, some of general interest. Let it be said immediately that the only feasible mode of communication known to us between creatures living on different planets moving around different stars would be by a radio link.

The optimum radio wavelength for such a, a link is around ten centimeters, a few inches. And if we could have the next slide. Here, you will see in the, in the next slide, this is a, a– not an actual thing.

It’s a kind of drawing of a vast array of nine hundred individual radio telescopes, each intended to have a diameter of a hun- A-about a hundred meters, essentially similar to the largest fully steerable radio telescope yet constructed at Bonn in Germany. The, the building of, of such an array has been seriously proposed. It is, uh, calculated that, uh, it will be possible wi-with it to receive messages, uh, transmitted at what we regard from our state of our present-day technology as, as a reasonable power level from creatures living on a, on a planet moving around any star anywhere in our galaxy with such a thing as this.

So such an array would give full expression to our present-day ability to construct an instrument capable of achieving inter-interstellar communication. And this proposal has been named Project Cyclops. And its cost has been estimated to be comparable with the cost of the Apollo program of landings on the moon.

That is the order of financial cost. Could you have the lights up, please, again? It’s worth mentioning that actual physical travel by men in space doesn’t seem to be possible to distant stars.

And even if it were possible, physical travel would take much more time than an, an interchange of messages through a project like this. The likelihood that physical travel to distant stars is impossible seems at first sight to be a decline in romantic possibility, a sort of loss of richness in the scheme of things. But a little thought will soon show you that precisely the opposite is true.

If physical travel from one planetary system to another were feasible, were feasible, then the first creatures to become technically capable of space travel will be likely to spread themselves everywhere throughout the galaxy. Just as science fiction writers are always imagining the human species to do. It would be only too likely that the galaxy would thus come to have only one form of intelligent creature, and this indeed would be a loss of richness.

But with space travel, physical space travel, not possible, creatures in one planetary system can’t interfere with the physical development of creatures in other systems. Many possibilities with great potential richness are then permitted. So this brings us to the question, are other intelligent creatures really likely to exist?

In the early part of my talk, we saw that there’s little, if anything, in our own planetary system that appears to be due to what we might call distant chance. To be sure, if we knew there to be only one other planetary system in our galaxy, the odds would be against it containing a planet like the Earth at an, at an appropriate distance from an appropriate central star with a similar rotation speed and similar physical properties and similar, similar chemical properties. But the chance of a favorable situation wouldn’t be all that small, perhaps one in ten, perhaps one in a hundred, but probably not much less than that.

And since we haven’t just one other planetary system to consider, but probably something like a hundred thousand million of them, we’ve no real difficulty on this score, as we already– or as I’ve already emphasized. So as we saw, the, there’s also a well-founded chemical logic in the form of life that we, uh, find here on the Earth, and i-it is so well founded, this logic, that one would expect a similar logic to quite likely have arisen in many places, perhaps many millions of places. But then, then you can go on and say, would such life become intelligent in the sense we’re now discussing intelligence?

Well, from our consideration of the nature of an animal, this, uh, business about the electronics, it seems very likely that, that electronic systems, uh, would develop for all animals everywhere. So the need to search for food, eyes would be a normal development, one might think. Animals with e– with eyes are then likely to prey on each other, with biological evolution forcing the development of what I might call in military terminology, weapon systems, claws, teeth, and ultimately a thinking brain, the most deadly weapon of all.

The logical sequence leading to the emergence of a thinking brain appears inevitable, and we can expect this to have happened quite generally. So I keep going through a series of questions, and so far I’ve been giving you positive answers, but I come now to what appears to be the most uncertain question of all. Given a suitable planet, given the origin of life, given the emergence of intelligence to a level at least equal to our own, for how long on the average can we expect such an intelligence to persist?

Even if intelligence arises in as many as a million cases in our galaxy, there’ll still be very few such cases around now at the present moment, unless high intelligence, once it arises, persists for more than ten thousand years. This is simply because the age of our galaxy, the time span over which intelligence emerges, is very long indeed, about ten thousand million years. And unless intelligence lasts once it arises, there’ll be very little overlap in time between its brief emergence on one planet and its emergence on another planet.

The thought that our capacity to execute a project of the technological quality of Project Cyclops might only last for a timescale of ten thousand years seems at first sight to be a pessimistic assessment of the future of the human species. But in view of the state of our present-day society, isn’t it rather an optimistic assessment? When one contemplates, and I’m quite serious now, the huge human populations that have grown with startling suddenness on a timescale of only a century, when one contemplates the excessive modern pressure on natural resources, it’s hard to summon much confidence in a future extending more than a few decades.

Devastating crises, one feels, must overtake the human species in a timescale no longer than a hundred years. We’re living today, not on the brink of social disasters as we often tend to think, but actually within the disaster itself. And that’s exactly what the news media are telling us every day.

We’ve seen that the phenomenon of intelligence is an outcome of aggressive competition. Intelligence and aggressiveness are coupled together inevitably from their biological association. An intelligent animal anywhere in the galaxy must necessarily be an aggressive animal and must necessarily become faced at some stage by the same kind of social situation as that which now confronts the human species.

Inevitably then, intelligence contains within itself the seeds of its own destruction. And my final question really is, can any solution be found to this inherent difficulty? The difficulty is quite inherent in the, in the whole nature of the, of, of the situation.

Well, we can approach this, this final question by considering what condition will be needed here on the Earth in order that our species may continue to maintain itself at a high technological level for a timescale signific-significantly longer than ten thousand years. A much lower population level will be needed, pressing only gently, if at all, on the resources of the Earth. It’s hard to see how our strident, competitive, present-day society could evolve in– smoothly in a more or less trouble-free way to the needed lower population level, or to see the persistently quarrelsome present-day human temperament changing voluntarily.

To achieve such a change psychologically as well as physically, an extensive selection of the human gene pool will probably be necessary. Some few individuals probably exist today with the necessary qualities. I won’t say who they are because I don’t know, but it’s from the progeny of these few individuals that the population of the future will be required to come, and the remainder of humanity bearing the characteristics of our aggressive past will be required to become as extinct as the dinosaurs.

It’s possible in the violent future which lies ahead of us that these things will come to pass, yet I regard it as much more probable that they will not do so. Inevitably, it seems to me that the human species must then relapse back to its primitive condition. It seems that our moment of intelligence, in a technological sense, will be exceedingly brief, and that our ability to give expression to Project Cyclops won’t last for more than a century or two, perhaps not more for– more than the next few decades.

I see the uncertainties which now lie ahead for the human species as being an inevitable obstacle in the way of the emergence of any long-term intelligence. And I see it as an obstacle every bit as formidable as the early physical problem of obtaining an appropriate planet moving around an appropriate star. And I see it as a barrier every bit as crucial as the origin of life itself.

I suspect many creatures reach our particular stage of development, but that only a few are able to go any further. Perhaps the chance of successfully surmounting the obstacle is as high as one in a hundred. Well, suppose each successful creature then has a lifespan as long as a hundred million years.

On these reasonably favorable assumptions, I would suppose, the number of long-term intelligent species in our galaxy at present alive wouldn’t exceed about a hundred. And it’s among these fortunate few that I’d expect interstellar communication to be taking place at the present time. The nearest of these, of these few will be likely to be distant some three thousand light-years away from us.

So I reach now toward the end of my last few sentences of what I want to say to you. It’s to be observed that for a species with a long-term future of a hundred million years ahead of it, a necessary interval of a thousand years or so between the transmission of a message and the reception of a response to it wouldn’t seem a serious impediment. There’d be ample time for many messages to be interchanged.

But in our human case, it’s unlikely that much popular or political support will be forthcoming for, uh, an enterprise such as Project Cyclops, which I showed you a few moments ago, once it’s understood that perhaps many centuries would be needed to obtain a positive result from it. Only if results could be promised in the short term would I expect such a project to receive popular, popular support. And this indeed I take to be clear evidence of the ephemeral nature of our modern society.

We have no faith in tomorrow. I would say, and this is– I want– the thought I want to leave you with, a species with a, with a real confidence in its future that really had– knew it had a future ahead of it, wouldn’t hesitate at all to give expression to a project as m-magnificent as, as, as that we’ve seen in Project Cyclops. Thank you.

(applause)

[00:53:47] PROFESSOR PARK:
That, uh, on that cheery note, we conclude the Hitchcock Lectures in its sixty-fifth year. Uh, I hope we have another sixty-five years. Thank you.

(laughter)

(applause)