TOPICS > Science

Nobel Prize

October 8, 2002 at 12:00 AM EDT


RAY SUAREZ: This year’s Nobel Prize in Physics went to three astrophysicists. One of them, Riccardo Giacconi, is known as the father of x-ray astronomy. He is President of the Associated Universities Incorporated, a nonprofit company that operates astronomical observatories for the academic research community. He joins us now.

First of all congratulations. It must be quite a thrill to get that call.

RICCARDO GIACCONI: Yes, even though it was very early in the morning.

RAY SUAREZ: Now as the father of x-ray astronomy, you were guessing that if we looked for x-rays coming from space instead of just the light of the stars, we’d learn something?

RICCARDO GIACCONI: Well, let me put it this way. We were hoping to find x-ray star. We didn’t know for sure what they would be. We were lucky enough to see them, and what was really surprising was how bright they were in the x-rays. And that implied that they were different kind of stars than our own sun. In our own sun only a very small amount of light comes out in x-rays. In these objects that we found, most of the light comes out in x-rays.

RAY SUAREZ: So they’re really shining in effect but shining in a part of the light spectrum that we can’t see.

RICCARDO GIACCONI: That’s right. You’ve got it. We saw the first one in ’62 and then it was a question of how to explain this. There were many, many explanations. None of them worked out. What it turned out in the end was that these were not single stars. They were two stars in a binary system rotating around each other. One was a normal one. And the other one was a star at the end of its life. And when that happens, stars collapse and become very small, very dense, and they are either neutral stars or maybe if the implosion doesn’t stop, they become black holes. So that’s what was producing all of these tremendous x-rays that we were seeing.

RAY SUAREZ: Now, when you looked using these new instruments, new technologies, looked and saw this different view of the world, did it change the idea that we had of space as graceful, slow moving, sedate almost?

RICCARDO GIACCONI: Well, we had a, I think, a vision of evolution of stars as being a very, very slow process, which occurred with great majesty over very, very long times. I think that much of modern Astro Physics –particularly x-ray astronomy — has given up an impression of a universe which is completely different. It’s a place where stars die and enormous explosions as super novas where they pulsate very rapidly, where change is continuously occurring and huge energies are liberated, which essentially drive the evolution of the system. So it’s a rough place out there. I mean it’s very alive and very full of action.

RAY SUAREZ: And it’s a fast- moving place as opposed to that sort of slow and graceful world.

RICCARDO GIACCONI: Yes, well, of course — over enormous periods of time, but events can occur very, very fast. I think that what we are seeing is, well at first we saw these very bright objects, which were very strange but now we have extended x-ray observation to objects of all kinds in the universe. And with this telescopes that we have developed, we can see objects as far away as in any wavelength range. We see some of the most distant quasars, some of the most distant galaxies, some of the most distant clusters of galaxies and normal stars. We also resolved recently just with Chandra in the last year, the mystery, this fog this x-ray mechanism we couldn’t understand. Now we resolved these individual little objects.

RAY SUAREZ: Chandra is a data collection tool, an x-ray collection tool.

RICCARDO GIACCONI: It’s an observatory, which NASA sent very recently up.

RAY SUAREZ: When you send up something like Chandra, do you go up already knowing that there’s a piece of cosmic real estate you want to look at or do you just have Chandra look and tell you what it sees?

RICCARDO GIACCONI: Chandra is very difficult to get to observe. It’s very competitive. For every five proposals, four are turned down. So you only get a 20% chance to observe. I was lucky I got some time on this. To get a lot of time is very difficult. But you do point… you have to explain what you are trying to do and where do you want to point in the sky. And you start at that particular object or that particular patch as best as you can. To just wander around would be a very time consuming exercise.

RAY SUAREZ: What is there still to learn using the science that you helped pioneer?

RICCARDO GIACCONI: Well, x-ray astronomy is not alone in astronomy. I mean it’s working together with visible, live astronomy, radio astronomy and many other disciplines, neutrino astronomy. And what we have to learn is basically the same problem posed again and again and again. From initial chaos we have an ordered universe. We have stars, planets, living beings even. How did that come about? What is the connection between the original chaos, the formation of these large objects, the formation of stars, the formation of planets and so forth? We want to explain how it happened. By using x-rays, we find out in particular what happened during the big explosions. For instance, in our body, the hydrogen comes from the big bang. It was there initially but the iron could only be processed through stars and mixed in to the cosmic… with the inter-stellar matter to form the iron and the hemoglobin. And so we couldn’t exist without super nova explosions. We are children of both the big bang and super nova explosions, which happened later. We have very close. It’s not that indifferent to us, what happened.

RAY SUAREZ: So there’s a little bit of star in all of us, I guess.

RICCARDO GIACCONI: Absolutely. Absolutely.

RAY SUAREZ: Ricardo Giacconi, again congratulations and thanks for being with us.

RICCARDO GIACCONI: Fine, thank you.