James Peebles Interview: Conversations with History; Institute of International Studies, UC Berkeley

A Cosmologist’s Intellectual Journey: Conversations with James E. Peebles, Professor Emeritus of Cosmology, Princeton University; October 12, 2006 by Harry Kreisler

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Being a Scientist

I get the sense in your lecture and what you're saying now that this community that you're a part of -- and it may transcend the particular subfield within physics, it may include all of the sciences -- that there's a movement forward as the collaborations emerge, or the insights emerge, which then influence your own thinking. You suggested that in your dissertation.

Oh, yes, yes. We build upon previous work. It's so important that we have a basis of knowledge and understanding that we build upon, and (we hope) add to, for the next generation. By no means is any one individual -- one of my heroes is Bob Dickie, my teacher, but I have to admit he wasn't essential to the game. Others would have done what he did. What is essential is that institutional memory. I sometimes think of science as a craft in the sense that you learn it from the previous generation who learned it from their previous generation. I would hate to imagine doing science de nouveau. To start all over again would be to start all over again! We'd have to go through another Galileo, another Newton.

This touches on a question I always like to ask the scientists. That is, what are the skills that people should have, and also, what are the virtues that make for a good scientist?

In part, the most optimum skill is a function of time. As the subject evolves different skills are needed. I have the strong feeling, for example, that another respected figure, Fritz Zwicky, was just right for his time in astronomy when there were lots of new ideas poorly explored, but who might not have done so well today when we have a fixed set of ideas that we're trying to build upon. He was too independent minded, in a way. It's good to be independent, of course, but you have also to pay attention to what other people are thinking. He didn't like doing that. That was right for his time, now it's not.

Of course, there are surely general features that people should carry along and one of them is intellectual honesty. "Did I really say that?," you may ask yourself. "Oh, what a stupid thing to do." In life it's very difficult to say that sometimes, but if you're going to do well in science you'd better learn from your mistakes. So, that is one: introspection. Ask yourself, "Did I really mean that?," and "Is this observation really consistent with my fixed beliefs?"

There are many kinds of science, too. There is the deeply mathematical sort, like superstring theory. Those guys can't pay too much attention to the data because there isn't much that's relevant to their deep ideas. On the other hand, the kind of science I love doing is that which comes into pretty close contact with what people are measuring, and there I see a lovely interplay. What are the observations suggesting? What does the theory suggest? Are they really consistent?

Curiosity, of course, in any human endeavor surely, and interest in what's going on. Mathematics? I have never been a very good mathematician. I struggle with it. I hate it.

You must be speaking relatively!

I don't know, but it is true that I only do mathematics because it produces this wonderful interaction between theory and observation. If that weren't happening I would do something less difficult. What would it be? I don't know.

One of the themes that emerged in your lectures, and often in my discussion with scientists, is a willingness to collaborate but also compete.

Oh, yes. We're a nasty bunch. We try to get ahead of the other person. That's partly just human instinct, isn't it? You like to run faster than that friend next to you when you jog. Competition. It's not unhealthy. But cooperation -- we'll get nowhere without it. And so, yes, "I have to admit you have the better argument there, but I'm going to get you next time." Competition, very important though. Why? As I reach the golden years I feel less competitive but I still want to "beat up" that other person!

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