DEBORAH AMOS, host:
Two Americans have won the Nobel Prize for physics. John Mather and George Smoot were instrumental in building a satellite that measured ancient radiation left over from the creation of the universe. The measurements confirm the Big Bang theory and helped explain why galaxies cluster together in outer space. Joining us now to discuss the prize is NPR's David Kestenbaum. Good morning.
DAVID KESTENBAUM: Good morning.
AMOS: David, what was this spacecraft that helped win these two men the prize?
KESTENBAUM: It was nicknamed COBE, which stood for the Cosmic Background Explorer. And it was actually an idea from the early '70s, and it was supposed to be launched on one of the space shuttles. But that was delayed by the Challenger disaster in 1986. And eventually, they had to launch it on a rocket in 1989. John Mather at Goddard Space Flight Center, one of the winners, is described as the true driving force behind the collaboration, which was over 1,000 people. And George Smoot, who's at the University of California Berkeley, was in charge of one of the instruments onboard.
AMOS: And so what did they find?
KESTENBAUM: They were studying very precisely the afterglow of the Big Bang. So this is radiation that was produced as part of the Big Bang and still around today. And it's getting cooler and cooler. And this - so it's billions of years old. And it really provided strong evidence that the Big Bang really happened, and it's the best description for what happened at the beginning of the universe because it was the only theory that could explain the precise pattern of radiation that they saw.
And literally, when they presented the results at a conference after they were published in 1992, they got a standing ovation. And the experiment also looked for hot and cold spots in the radiation in different parts of the sky, and they found them. And that is seen as evidence for why we have galaxies that kind of clustered together, and then you have big, open patches of the universe. And then you have galaxies that cluster together. So it gave an explanation for the sort of fundamental structure of the universe.
AMOS: But I've read that two other physicists already won the Nobel Prize in 1978 for discovering this radiation. So how did these two scientists push the science along?
KESTENBAUM: Right. So that was a - that's a great story, actually. That was Arno Penzias and Robert Wilson, and they discovered it in 1964. And they basically had this - they found noise in an antennae they were building, and they said what was that? And it turns out it's the same noise that's in your television when it's between stations. And it turns out that's the same noise from the beginning of the universe. And they originally thought it might be bird droppings or something, and then they finally discovered wow, this is left over from the Big Bang. And so this COBE, this satellite was able to measure it in very, very precisely and to look for actual differences in temperature - very small differences in temperature of the radiation.
AMOS: Wow. So the Big Bang is on your television set? That's amazing. You mentioned that this experiment was the work of over 1,000 people. So are the days of the eureka moment, are they over?
KESTENBAUM: I think in physics they may be rarer now because it's a very advanced, mature discipline. And scientists have always built on the work of other scientists. But now, trying to answer the big, big questions, the collaborations are often, you know, hundreds of people, if not more. And they require big, large, difficult experiments to do them. So, you know, it puts the Nobel Prize Committee in a bit of a bind because they have to then say, here are a thousand people, and is the leader the right person to pick? Or maybe the person who came up with the idea in the first place. It's a hard spot.
AMOS: Thank you very much for explaining that one to us. NPR's David Kestenbaum.