Now, as it happens, the denser places, we proved, have enough gravity to sort of make the Big Bang radiation lose a little bit of energy coming out of the gravitational field. So what we see is that the dense regions look faint to us, because the photons have lost energy coming out, so that’s what we measure, and COBE made a map of that.

NTB: Having established that the Big Bang did occur, do we know what caused it and how long ago, approximately, it occurred?

Dr. Mather: Well, we do know when it happened. It was 13.7 billion years ago, plus or minus a little bit. And no, we don’t know what caused it. We have lots of stories about it, but I don’t think any of them can be proven.

NTB: Are you continuing to do research in that area?

Dr. Mather: Not me personally. Other people do, of course. One of these days we hope to have a theory of nature that explains the quantum mechanics of gravity. So far, we don’t have one. A lot of people have tried, but we don’t have one that works, so we don’t know. We would need such a thing in order to understand the Big Bang itself, or so we think.

NTB: Your work in this area resulted in you sharing the 2006 Nobel Prize for Physics with your research partner, George Smoot, from the University of California. Can you describe for our readers how it felt winning the most prestigious prize in science?

Dr. Mather: Well sure. It was a tremendous recognition for me personally, for the work that we’d done and, I think, for the whole COBE team, which was a very large team. It was very important to them, too. Somewhere, back then, we knew our work was important, and now the entire world knows that our work was important.

NTB: That’s a good way to sum it up. Are you the only NASA scientist ever to win a Nobel prize, or have there been others?

Dr. Mather: Well, I’m the only civil servant. We’ve had other space scientists win it. Riccardo Giacconi was the father of X-ray astronomy and was also the director of the Space Telescope Science Institute for quite a few years, and he did win the prize (physics – 2002).

NTB: You currently chair the science working group of the James Webb Space Telescope (JWST). Tell us about that project. What will that telescope do that its predecessors couldn’t do?

Dr. Mather: Well, the short version [of that answer] is that it’s bigger, more powerful, and cold so that it can observe infrared radiation, which comes from two quite different but important places. One is the most distant objects in the universe. We get the infrared radiation from them because of the expansion of the universe; that makes a red shift.

The other major place is things that are a lot colder than stars, like planets and people, emit infrared radiation but not very much visible light. So we can study places where planets are being made, where stars are being made out of the cold material of space. That’s the major difference you get with infrared technology.