The George C. Marshall Institute






A Conversation with Dr. Frederick Seitz

September 3, 1997

Dr. Seitz is former President of the National Academy of Sciences, past President of the American Physical Society, President Emeritus of Rockefeller University and Chairman of the Board of the George C. Marshall Institute. The interview took place on September 3, 1997 in Dr. Seitz's office at Rockefeller University.

GCMI: Why did you become a scientist?

Seitz: It just seemed to come naturally. My father was deeply interested in science and was well-read, although circumstances never gave him an opportunity to become a professional. He was one of those individuals who spent his spare time as a young man not in a bar but in going to scientific lectures.

GCMI: Where is the place for the amateur scientist today, given the complexity and expense of science?

Seitz: Well a lot of them do things like join astronomy clubs. Some of them build telescopes. Some of them discover comets.

GCMI: So you think there is still a role for the amateur?

Seitz: Yes. But it's easy to be sent in the wrong direction today.

GCMI: Such as?

Seitz: I carry on correspondence with some very nice people, but they participate in all kinds of confusions, especially as regard to the nature of the atom.

GCMI: Many laymen picture atoms as a little solar system. That's not quite it, I guess.

Seitz: That was Bohr's original proposal. Rutherford had found experimentally that the atom contains a positively charged nucleus that contains most of the mass and is very small compared to the size of the atom. Bohr found that if he assumed an inverse square law of attraction between an electron and the nucleus and introduced restrictions referred to as quantization you could describe the discrete energy states of the hydrogen atom. The model assumed that the electrons in the atom moved in planetary orbits about the nucleus. The model became very popular for descriptive purposes, but it worked only for hydrogen. In the 1920s, Einstein found a paper written by a French physicist, Prince de Broglie, suggesting that if light could behave like both a particle and a wave the same should be true for electrons. Einstein proposed that a fellow physicist, Erwin Schroedinger, look into this matter. Schroedinger generalized de Broglie's concept and in the process developed the famous Schroedinger wave equation. In parallel and independently of this, Werner Heisenberg followed another lead and developed what has become to be called matrix mechanics which contains within it the concept known as the Heisenberg uncertainty principle. The two developments were different approaches to the same theory.

The world of sub-atomic particles is a different world from the one we think of everyday, but it's the real world nevertheless. Our everyday world is a kind of extrapolation of it, to large bodies. The uncertainty principle still bothers people, but there is no getting around its validity on the atomic scale.

GCMI: Physicists always try to rely on real-world analogies, but what you're suggesting is there's almost no real world analogy to suggest to the layman what is happening in the sub-atomic world.

Seitz: Please understand there's no gap between Newton's Laws and recent discoveries in quantum physics. You obtain Newton's laws if you go to sufficiently large bodies and start applying the quantum laws. Experiments carried out at the micro level have been used to test these concepts and the results may seem unbelievable but they are real.

GCMI: Would you explain what is unbelievable.

Seitz: We encounter real paradoxes. People find it hard to comprehend that a particle can behave like a particle?we think perhaps of a baseball or a golf ball?and yet have wave properties at the same time. And yet that's the way it is. I grew up with those things. A generation older than mine found it harder to go along with these discoveries. I guess the younger generation more or less take it for granted, although we've always had people in each generation who have been trying to disprove it, and some of them very good scientists. But in the last ten years, some ingenious experiments have verified the paradox.

GCMI: What's been the most surprising discovery by science during your career?

Seitz: That is hard to say. Let me put it this way: the physicist is a very special breed of animal. Surprises are part of the game.

Ocean floor spreading, for example ? I happen to live on both sides of that discovery. The real driver, Harry Hess, was a geologist?He noted that there were no rocks in the ocean floor older than 100 million years whereas the earth is 4.5 billion years old, so he said something has to be moving, and it must be the ocean floor. Now that concept had been proposed earlier by Wegner early in the century. However, the geologists of his day ran him out of court. Experiments prove, however, that both Wegner and Hess were right. Another example, of course, is the gradually growing proof that at one time the universe was very tiny and expanded as if by an explosion ? the Big Bang Theory. I would say that new concepts such as those have come less by surprise, and more as a source of enlightenment?.

GCMI: Could you tell us a little about your latest book?

Seitz: It will be called The Electronic Genie: The Tangled History of Silicon in Electronics. Actually, I think that the publisher doesn't like the word "tangled" so we may drop it.

GCMI: What is the conclusion that you've drawn from this history?

Seitz: Well, it gives a perfect example how, over a long time, things that people learn purely out of curiosity can have a revolutionary effect on human affairs. It's an almost ideal example. People didn't get interested in crystals in a formalistic way until the 1700s. A French scientist, Just-Hauy started studying the angles along which crystals fracture and found that they were always the same for a given mineral. Discoveries went on from there.

GCMI: The popular understanding is that the computer revolution was largely driven by entrepreneurs in garages and you're reminding us that there are scientific heroes in this story.

Seitz: Take Ferdinand Braun, for example, the man who discovered rectification in crystals. Later he received the Nobel Prize along with Marconi. He had three great discoveries. One was crystal rectification, which is the seat of the useful properties of semiconductors. He invented the electron tube that today is the basis for that employed in television sets. And then he's the one who, after Marconi got stuck and couldn't transmit more than fifteen kilometers, noted that the circuitry Marconi was using was wrong?.

Silicon, as used in electronics, emerged to our attention in a very strange way. In the 1890s the metallurgists started alloying steel with various metals and someone discovered that elemental silicon, which up to that time had been a chemist's curiosity, was a cheap effective alloying agent. So it was soon being produced in practical quantities. As wireless telegraphy evolved, interest developed in rectifying the signal. The signal is received at a very high frequency. If rectified, one obtains a continuous pulse like a bump instead of something that just jiggles at high frequency. So it will make a more pronounced signal in an earphone. Silicon was found to be the best rectifier. And that fact has tracked right through the whole history of its use in electronics?..

GCMI: Let me go to another area. What has been the most significant change in the American scientific community during your career?

Seitz: Well, first, there's been the growth in size of the scientific community in the United States. In the last century, people had only very peripheral interest in science. It picked up about the turn of the century when in order to fit into the ongoing pattern of world commerce we developed the Bureau of Standards. In the meantime, the National Academy of Sciences and the Smithsonian, which had been created mid-century, were of interest to a few specialists.

During World War I, we were cut off from some major sources of chemical supplies and thrown on our own. Chemistry soon became a rapidly growing field. Physics was mainly in the background, being led by a few individuals having a great time, but largely ignored. World War II changed all that, of course. Indeed, the nature of the scientific community changed. Many individuals who previously would not have thought science offered a good career entered the field.

There has been at least one negative consequence of this growth. It has contributed to a politicization of many fields of science. Budgets are getting almost beyond national capability as perceived in Washington?.

I am very much worried about gene research; notice the reaction to the recent stories on cloning. Immediately after sheep had been cloned, individuals on the Hill and the President were making television statements about morality and the need for legislation to limit cloning. Cloning was bound to come and eventually we will see human cloning.

GCMI: Is the concern that the most beneficial kinds of research won't get done because the most politically attractive research will get the funding instead?

Seitz: That's right. Here is an example. I'd love to know more facts about halogen compounds that come out of volcanoes. If I went to a federal agency and asked to get funded for such a study, they would probably throw me out. Why? Because looking at this question assumes the need to look further into issues related to possible sources of presumed depletion of ozone. It would also suggest that the concept that man-made CFCs are the greatest threat to the ozone layer may not tell the whole story.

GCMI: Do you have the outlines of a solution?

Seitz: A cure? I don't know. The trouble is that you won't get the scientists to agree on a course of action. It is almost instinctive in science to accept contrary views, because disagreeing gives you guidance to experimental tests of ideas - your own and those offered by others?.

GCMI: A few final questions. Do the recent discoveries in physics that we discussed in the beginning of our talk undermine or support a faith in God?

Seitz: We are immersed in a mystery so great that it's utterly beyond me. Clearly, something quite big is going on that we are not as yet and may never be privy to.

GCMI: Are there things that science should not investigate?

Seitz: I can't imagine any such thing. I regard knowledge to be neutral. The use to which knowledge is placed is a different matter.

GCMI: Thank you for your time.

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