The Chicago lectures; Willard F. Libby, part 1

National Educational radio in cooperation with the University of Chicago presents a short series of lectures designed to initiate a new discussion on the nature of man his place in the universe and his biological intellectual and social potentialities. This lecture the first in the series is entitled man's place in the physical universe. The speaker is Willard F. Libby professor of chemistry and director of the Institute of geo physics at the University of California in Los Angeles. Here now is Professor Libby. The subject of man's place in the physical universe it seems to me can be attacked by examining first this present situation and environment and then considering his present role. And then finally his proper place. The present situation environment breaks down into three major categories as I analyze it. The first of these might be called The Nature of time. The idea of progress. The existence

of history. The notion that a beginning and then a time exist. We have a mission and that our accomplishment of it will fold up into the time unrolling. In the present from the past into the future it may surprise some of you in the audience to note that this is a major point. It's a strange property of the fundamental laws of physics that they are independent of the sign of time and would allow time to run either way. So we can imagine a type of universe in which the passage of time was a purely local matter and in which on the average

There was a steady state contest shouldn't which lasted indefinitely. Now there's one thing we know about our environment and that is that that is not so of our particular part of the universe. We know this by a number of physical measurements using radioactive time clocks. We believe that our earth. It is about 5 billion years old in the sense that this length of time is a lapse since it was assembled. We find this by reading the amount of lab made by decay any uranium and thorium radioactive isotopes. The amount of argon made by decaying radioactive potassium the amount of strontium 87 aided by decaying rubidium

all of these different clocks operate at different rates and yet they give the same reading for the total elapsed time within experimental error and we find that the oldest rocks on the Earth's surface major something like 3 billion years. Working with the media rights we find that the main group of meteorites. That fall in from outer space Major around five million years. So we have five billion years as a result of all figure for the time at which matter congealed from the solar nebula. And presumably this matter remnants of which exist in the main group of meteorites is the matter from which the Earth itself and the other

planets are made. Most of the evidence is pointing in one single direction namely. That our solar system and our star. Is somehow running down. And that there will come a time some billions of years in the future when the sun will no longer shine and the planets will fall into the sun. And we can now foresee an end to our epic. In other words all our indications or most of all that we know tells us that time is passing in one direction. That's very necessary to be careful in discussing such fundamental points as this one very necessary to stay close to fact or it's very easy

to turn off into fantasy and metaphysics on such a basic question where the human influence and prejudice may become determinative. I would say that we would be safe and making the following statement. Time is unit directional. In our part of the universe. This does not necessarily apply to other parts of the universe. Now having the idea of time and the notion. Of development and of history and the idea of progress we can better our drafts ourselves to the question What is man's place in the universe and what is his role in its unfolding. There's more to our environment than just the fourth dimension of

time. We've got to consider some of the plain physical facts which may or may not be taken for granted but which are of paramount importance in answering this question. And one is the uniqueness of man. It would seem from the evidence that we have. That life may be a natural chemical consequence of the development of our planetary environment and that in all probability life exists on many other planets and many other stars. This seems to be probable. Now let's look in a little more detail at the points that lead us to this conclusion. First there is something truly magic in organic matter

which allows it to proliferate in the X strawberry variety of ways we observe in living systems. We can only admire the structural beauty and the elements of symmetry in biological molecules and look on in amazement at the delicacy and fineness of adjustment of the structures which contribute to our very substance. It's of course an old argument as to whether a divine being lends this magic touch. It seems to me that at the moment there is not any scientists capable of doing the magical chemistry which the human body and the bodies. Of all animals and all living forms performer routinely We are now at the beginning of a time of true understanding of chemical biology and it may well be centuries before we arrive at the point of being able to make even the simplest form of living matter

synthetic. Yet there is a principle. There is a principle here which is difficult to state which you might call a principle of life in organic matter can be converted into organic living substance and vice versa. Carbon dioxide and water. Of the air. With a little of the salts from the sea and the soil. Together with sunlight make the green plants which in turn nurture the animal kingdom. How brilliant researchers have elucidated many steps in this magical mechanism but few would argue I'm sure. Against the thesis that there is no one alive today nor is there likely to be one in the next few generations who can set up the entire elaborate machine. How did this machinery start.

We know from some very important experiments which were done here at the University of Chicago twenty years ago by Dr. Stanley Miller then a graduate student professor Harold Yuri. The Enrico Fermi Institute and chemistry department at simple organic gases. Such as water ammonium methane when subjected to electric discharges produce some of those. Essential elementary molecules namely the amino acids on which life is built. These amino acids which are the building blocks for the proteins. Therefore can be understood as being present and ready for the magic wand or magic back to life giving touch which marks the

beginning of life. These foodstuffs are naturally present as a normal part of the evolution of the planet in our own laboratory at UCLA. We've been studying the fundamentals of the mechanism the Miller-Urey synthesis. And it is truly remarkable how the effect of radiations from the sunlight can take the simplest of materials such as methane. One of the simplest molecules C-h for and convert it and who. Has every hydro carbons of the general character of lubricating oil. No one would expect life to start on lubricating But in order to understand the million euro mechanism we've been restricting ourselves to this simple molecule and we see that the magical synthesis of Miller in your way does not require

electric discharge or lightning storms It merely requires sunlight sunlight of the ionizing variety sunlight of the kind which makes our radio waves bounce back from the top of the atmosphere. We've also observed that this same reaction will occur whatever the nature. Of the state of the methane molecule it will work. Even then the solid at very low temperatures the Hill during a long time ago made an incontrovertibly argument. That in the beginning of the solar system. There was a great deal of methane he said that the whole environment was in what is known as a reducing condition. We're in an oxidizing condition now on Earth because we have oxygen in our APIs fear. On the other hand Dr Yury made a persuasive argument that this

was a later development and that the remarkable Plimer ization reactions which would make the foodstuffs on which life developed were a normal event in the course of the formation of the planet. Now we're more certain of this now in fact I would say at the present that we are so certain that it is a rather than a firm prediction that the production of organic matter is an essential part of the creation of the planet itself and that we can expect that in the course of the collection of the dust to form bodies large enough to have gravity force enough to make further accretion possible. Some kind of magical blue was involved. And when we go to the moon we will find that there's a great deal of this residual organic matter on the moon. And I guess many of you know

that many of the meteorites which follow him have a great amount of extraordinarily complex organic materials present. All in all there's a little difficulty in saying that conditions probably developed on Earth which would support life. It's probable that the oceans were saturated with molecules which could at least be used by present forms of life. At the time that the atmosphere became oxidizing the earth is not quite heavy enough to remain reducing. I do John is a light molecule and gradually blows away because of the force of the sunlight and tearing it apart as it leaves the atmosphere becomes oxidizing and we approach our present condition. However the planet Jupiter is still in a reducing condition and we can well expect that the extraordinary organic molecules of

which we've been speaking are still being produced in large quantities on that planet. These conditions for life therefore are essentially a property of matter. At the same time however having the conditions for life not necessarily sufficient assurance that it will occur and few scientists have had the temerity to attempt to explain their magical transition from the animate to the animate in a scientific way. It's strange that many non scientists are inclined to suppose that scientists are complete agnostics in many cases. Seems to me very difficult to imagine scientists not having great respect for the beautiful larder seen in nature and for the magic which comes in organic matter when it springs alive. This is our

function here tonight to analyze social logical phenomena. But I think in passing one might know that in understanding how the whole stage can be nicely SAT or the waving of the life giving wand and the occurrence of the Americal or however you will describe it. We wait with bated breath for some understanding of how it happens. Incidentally very very few experiments are being done or have ever been done trying to generate life in the sense of taking inanimate matter and striking in the fire. I'm not suggesting this would be a good fruitful line of research but it's very interesting. It reverently few attempts have been made. It's not impossible to do. As you probably know life has a particular fingerprint on

the amino acids which constitute the proteins occur and what we call optically active forms that is they have a geometry which is specially appropriate and characteristic of terrestrial life. That is they will base a righthanded molecules in the sense of a screw that turned to the right. Advances forward now the mirror image would be the other form of molecule. Now as far as we know there is no life on Earth which crosses this line and apparently I say apparently it is largely not necessarily entirely your chance as to which type got started and control the development of

life on the earth. So if you generate light. You would likely 50 percent chance of making the other kind. And if you do then of course you will know that it wasn't contamination which is the great problem in this experiment. Incidentally the same technique will be usable when we go to Mars to see whether there's life there. I wonder why they may not be in the audience tonight. Some young man or woman who will think this experiment worth attempting. What an event it would be in man's history if this could be done. You see a sign this is open to suggestions of experiments and despite the and respect we have for the giver of life we might still be willing to test to see whether we ourselves might not have done it. Some may say this is sacrilegious and scold us for

attempting. Fortunately for mankind in the world I think we passed beyond the time in most societies at least when scientific experiments are forbidden because of religious or social logical considerations. As much debate as to whether social consciousness on the part of the scientists should dictate or control its line of experimentation and sinus and cells divide to some degree. But I think the majority of scientists believe that it should not and that trolls should always be the goal. That seeking the truth is his proper business and purpose. I personally would like to see this great experiment try with all the modern techniques now available. So the question of contamination could be handled and we could come face to face with the matter. Is the evolution of life a natural property

of matter which is giving birth. To a system of planets surrounding a star. To return to our broad job of the scribing man's present situation environment I have to add one other major fact about man before we can assess his role and establish his place in the scheme of things. This major fact is that man strangely enough is brand new and then he just becoming fully acquainted with his environment. All right ancestors if they be our ancestors that have been found in they all die by Burridge by Dr. LEAKEY. Our only sub two million years old and the evidence we have of early man do not reach beyond this relatively recent time.

That's by no means clear now how long we've been here but it's almost certain that our total span is miniscule as compared say to the dinosaur which lasted over a hundred million years. As a basic fact we arrived very recently. I've heard the statistics. Good authority that of all the man who ever lived a good fraction they're still walking around like 5 percent or 10 percent. Now this means that we're still discovering what the world is like and I'm just beginning to know. Understand ourselves. Certainly we're just beginning to get away from the earth into the space area to explore the rest of the solar system. But right here on Earth we have just barely begun to see what our own Earth is like and what we are like.

We have very distinct markers which we can use to go back in time and trace the development of man and thereby establish the recency of his advent. Man is the only animal that makes a fire because we go back in field archaeology and examine. We can use these telltale circular dark spots in the soil. If there are reasonable dimensions. Problem is to distinguish charcoal which is made by human campfires which from charcoal which is made by forest fires. And by using modern methods of dating we can determine when the fire was built and then coming down to more recent times. These earliest campfires go back about as far as we can go with the

radio carbon method about fifty thousand years in the area around the Mediterranean basin. But coming down the more recent times we have more recognizable artifacts so charcoal is a very common one even for the most recent cultures. We can in this way say that mankind is new. We know that he first arrived on the North and Central and South American continent. I say we know what the evidence is overwhelming that man first arrived here some 11000 years ago and then he arrived here probably from Asia by walking across the dried Bering Straits and down the West Coast in a pathway now submerged because of the fall the rise of sea level which attended the melting of the glacier which covered the continent at that time.

This perhaps is not so remarkable until you realize that we have 50000 year old man around the Mediterranean basin and we have all over the Americas. All kinds of other animals. So when this the Americas man is really brand new. He arrived full grown so to speak. We have skeletons of him and he would be indistinguishable essentially from the modern Indian in skills and intellectual capabilities are commensurate with those of modern man or war. We have basketry that he made which is truly remarkable. We have one deposit or cash of three hundred pairs of woven rope sandals. What your nine thousand years old. We have his arrowheads. We have the fact that he

moved rapidly to colonize all three of these giant continents. That is North America South America and Central America within 200 years. We have the fact that he lived off of mammoth bison and didn't bother with small animals. And in Europe going back 5000 years before this we have some of the finest artwork the world has ever seen and the colored paintings in the Lascaux cave. And yet just going a little back beyond this we come to a dark shadow. We really do not know our Cro-Magnon man came from. He appeared suddenly and he took over very very quickly. The most remarkable aspect of modern man is his newness. One of the most remarkable aspects. Now we can list at length months within our own lifetime adding further to

the statement that we're centrally waking up even our fathers and grandfathers knew only a small part of what we now know and I'm sure we all agree that our children and grandchildren will know far more than we do about the nature of our environment. The earth and the solar system and the laws of nature we have to take this as an important consideration. Hard gives you a feeling of the power of man and the understanding of what he can do in a very very short time.