Astrophysics

Could you explain to us exactly what an astrophysicist does?

There are lots of things. Astrophysics means applying physics to astronomical phenomena. If you try to relate what is observed in the universe to what one can understand on Earth, one tries to use the physics one learns from terrestrial study and apply it to astronomical phenomena. How does one do that? I can give you an example: you can imagine doing some experiment on the earth in which you make molecules of some kind, just create them, and you understand the mechanism by which they are created. There's a variety of possible mechanisms which you actually study. You can study it from an experimental point of view, and also by theoretical work, too; there are theories of these reactions that one can hope to work out. Given what one knows about the astronomical environment, you can try to marry the two, merge the two, so you can say what is actually happening in some astronomical circumstance.

So it's both experimentation in the laboratory but also a study of the stars themselves and of the universe.

It certainly merges the two. It's both the experimental and also theory. It's not just the measurements, but calculations, as well as the development of theories, and so on. Then one tries to merge that knowledge, use that knowledge to interpret the remote observations and astronomical events by [phenomena] like the color of a star. You know, stars have ages. When we put them in a sequence, we know their lifetimes, and why they behave the way they do. The observations are properties of stars, which one then tries to understand in terms of the processes of that we have studied on the earth.

Are there special skills that this kind of scientist has to have or acquire? Obviously, mathematics is very important, or at least it made your transition smoother.

It's absolutely essential. Without mathematics, you can't do astronomy, not today.

One of the positions that you've held as a scientist is editor of the Astrophysical Journal Letters, which is very important in the field. How did you come to occupy that position and what is involved in that set of tasks?

Well, firstly, the Astrophysical Journal Letters is the leading journal in the world in astronomy for cutting-edge research. The actual length of papers in the Letters -- the letter is just a paper. The Letters historical origin began as letters, but it developed into being simply brief papers, four pages in length at most. It's there to publish work that will have an immediate impact on what is going on elsewhere, and so it's supposed to be cutting edge. It's an express journal.

I agreed to be editor of it. My interest has evolved from atomic, molecular, and optical physics. I still do atomic, molecular, and optical physics, but it evolved from that to the study of the upper atmosphere, to the study of the atmospheres of the planets, to this larger astronomical domain. I felt I needed to learn a lot of astronomy in a hurry. I decided that's what I was going to do. That was, perhaps, thirty-five years ago. I looked to do astronomy, and so I thought, "If I take the editorship of this journal, I'll have to read all these papers. It will force me to, instead of just putting them aside and saying I'll read them later." It forced me to actually read them all, then and there. So I agreed to edit the journal.

I intended to do it only for two or three years while I caught up in astronomy. I was coming into astronomy, as I said, rather late; I never took a graduate course in astronomy. I thought that in two or three years I would be more or less up-to-date. I would know what the exciting things were that were going on astronomy, and I could then, hopefully, make some contribution myself. In fact, I ended up doing it for thirty years.

That position must have given you a real perspective on what it takes to nurture an intellectual community in a particular field. Do you have any thoughts you would share with us about the arduous process of nurturing and maintaining a scientific community like you are doing in this role?

I didn't particularly have that in mind as a purpose, though I suppose it did occur. I certainly took it as my responsibility to assist authors in getting their papers into a stage where they were publishable. And, certainly, I made choices as to what was interesting and what was not -- or what was not immediately interesting. It's not that it wasn't interesting, but just that this journal was for work that would have an immediate impact.

So I'm not sure how to answer your question. Certainly I was in a position and tried to help people, and to say at least what I thought was interesting. But in a way that was determined more by the papers that were submitted than it was by me. The papers that are submitted are all sent to referees, and the referees' comments are a major influence on what is actually published. In that way, I was really not making decisions myself; I was reflecting the wishes, the will, of the community. But I suppose in some sense, in my responses, I had something to do with molding that community. I don't want to use that word, really, but something of that kind.

I guess it gave you an insight into the personalities and difficulties of scientists trying to move science along.

Yes. I've often said that I took the job of editorship in order to learn astronomy. I did, and it worked. I really did read those papers. But at the same time, I learned more about people than I did about astronomy. It's interesting to see how people respond to criticism. Some are happy with it, take account of it and improve their work because of it, others just get angry. I tried to tell them, "Don't be angry. This referee report is saying something useful to you. Respond to it."

Not everyone has the opportunity that you had to get an education through editing a journal like this. So I'm curious about your thoughts about science education today, especially teaching undergraduates as you do at Harvard and introducing them to the subject matter. Is that an easy thing to do? So many people seem to be fascinated by the universe and what astronomy might teach them.

Well, I think so. I think intrinsically it's such an interesting subject, and they come interested already. So you don't really have to persuade them to pay attention, if you like, that this is an interesting topic. They're there because they've already made that determination. So the classes are always quite involved from the beginning. Of course, you try not to be boring. It's not that simple to use the mathematics to apply physics to a astronomy. They have to know the math, they have to have some mathematical skills, which sometimes they're not very happy about, and they have to know some physics. So it's not all exciting stuff; finally the application is. I certainly would be much happier teaching astronomy than anything else.

Do you find that the students are prepared to enter into this kind of work? I'm curious as to your sense of science education in this country.

Mathematical skills have declined considerably. I've been teaching in the United States since 1967, thirty-six years, and I have to say that the mathematical skills have declined. The students are not so well trained as they once were. These are very bright, very intelligent people, and they're not very good at mathematics, except those few exceptionally talented ones. On the other hand, they write well -- they write better than they used to.

Astronomy, or the stars, the universe, is something that recurs again and again in literature and in art. There's a universal appeal of the subject matter. Is that important? I guess what I'm curious about is how a scientist moves from there to an understanding of what it is that has so fascinated people ... explaining what has fascinated great authors and great artists.

I don't think the literature influences people to do astronomy very much. It may a little bit. I think it's just looking at the stars. That's what's so awe-inspiring, and generates an interest in people who want to understand a little better just what is going on. Of course, there are many popular articles. Astronomy attracts a number of very good authors who write in a very interesting way. I don't mean professional astronomers, I mean just science writers. Astronomy is a subject I think they do rather well.

Why is that? Is it just because what they see in the skies is so overwhelming in terms of its impact?

Some of the ideas are so extraordinary, they stretch the mind and make you wonder. I think it's the sense of wonder that these extraordinary things can be happening.

In the beginning of your lecture on the comets, you made references to literature, and you showed a work of art from many centuries ago in which there is a comet. I'm curious as to what extent you read a lot of literature on the side, or your art appreciation affects your work or what you want to look at, and then vice versa, does your work in astrophysics lead to a new appreciation of the art or the literature?

As far as reading literature is concerned, it's something that I do, and it's certainly always intriguing when it happens to have some astronomical connotation. So, certainly, from that point of view ... you mentioned my talk, and that was fun to discover in the literature these old references to comets. But it's not that doing science drives me into a particular literature. It's rather more accidental. Of course, if I discover it, then I will pursue it. But, certainly, the literature is a very ... that's what everybody does, you read.

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