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Nobel laureate John C. Mather spoke Tuesday at the School of the Art Institute of Chicago about the Big Bang and the James Webb Space Telescope, an international endeavor.


Are you made of exploded stars? A Nobel laureate has the answer

by Zack Aldrich
Nov 02, 2011


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Zack Aldrich/MEDILL

"As our imagination increases, our ambitions increase," Nobel Prize astrophysicist John Mather said. "The James Webb telescope is the latest in a series of increased capabilities, and I think astronomers, anyway, have at least a century’s worth of amazing ideas to go that are already thought of."

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Astrophysicist and Nobel laureate John C. Mather, 65, spoke Tuesday at the School of the Art Institute of Chicago. He was invited as part of a Brinson Foundation initiative to show the link between art and science. After speaking with Medill Reports, Mather gave a lecture vindicating the Big Bang theory, a scientific model positing that the universe expanded from a very hot state.

His work on the Cosmic Background Explorer satellite, which measured the color of heat radiation produced in the Big Bang, earned Mather the Nobel Prize in Physics in 2006. He is a senior astrophysicist for NASA and a senior project scientist for the James Webb Space Telescope, a 2018 space telescope project to examine what happened in the cosmos in the years after the Big Bang.

Q: What is learned from measuring the color of heat radiation from the Big Bang?

A: The idea is that the early universe is so hot and so dense that quickly things come to equilibrium, a kind of pressure cooker phenomenon where everything’s the same temperature, at least locally. There’s only one possible prediction for the spectrum of this heat radiation. You spread out the light, like with a prism, and see how bright it is at each different color. If it doesn’t follow the right curve, then the Big Bang theory is wrong. We took a small object with us called a blackbody calibrator that emitted just the way the early universe should look to us. When we moved the object into the apparatus, it looked just the same as sky. So, we very immediately concluded, ‘Yeah, the Big Bang is right.’

Q: Now that we’ve given credence to the Big Bang theory, how did all these elements come together to sustain an environment for human life?

A: The universe begins its expanse, and we end up with hydrogen and helium after the first three minutes. Then it keeps on cooling down and finally becomes transparent when the hydrogen and helium nuclei latch onto electrons. That’s after about 400,000 years. Then, another few hundred million years pass and the first stars turn on. They immediately burn out in a few million years and they liberate the chemical elements that fill up the rest of the universe. We’re made out of carbon, oxygen, nitrogen and such, and those are manufactured in stars that blow up. So, as soon as that first generation of stars exists, it’s conceivable that there could be life.

Q: What is the purpose of the James Webb Space Telescope?

A: It’s an international partnership doing this. It’s not jut NASA. Europeans and Canadians are both chipping in a lot, and the Europeans are even providing the rocket to launch it. When it’s up there, we would like to see how the Milky Way comes to be. Our Milky Way galaxy is 100 hundred billion stars orbiting around a common center. We think from looking at pictures of early galaxies that this probably happens by small little protogalaxies colliding and joining together in a rather chaotic but beautiful process. So the next thing people probably want to do is to look for the formation of stars like the sun, which is still happening nearby in dust clouds — which the infrared capabilities of the Webb telescope can observe. Quite recently, it’s been discovered that there is a comet that has the same isotope composition of water or hydrogen as the Earth oceans do, and this was the first we ever found one that matched. We’re also going to work on the dark matter and the dark energy, trying to understand how ordinary stars behave and how they come to an end. All the stars come to an end. Even the sun will come to an end.

Q: What was Einstein’s biggest mistake?

A: When he wrote his theory of general relativity, he applied it to the universe. And he said, ‘Well, everyone knows the universe is not expanding, so it’s pretty obvious to us that the universe must be static.’ Then, later on [American astronomer Edwin] Hubble showed that the universe actually is expanding. Now, we have revived [Einstein’s] idea because measurement shows the universe is accelerating. To tell you the truth, his little fudge factor that he put in worked perfectly to describe this acceleration, so maybe he was right again after all. Maybe it’s not a fudge factor. Maybe it’s something real, but we call it ‘dark energy,’ which means we don’t know what it is.

Q: How do we reconcile faith and religious doctrine with science of the Big Bang?

A: When [Belgian priest and physicist] Georges Lemaître met the pope, Georges Lemaître had worked out this Big Bang story, and the pope supposedly said to him, ‘Doesn’t your work support the biblical story?’ And George Lemaître … said, ‘No, it doesn’t.’ So, currently the pope’s position on science has been more like, ‘There are two different realms, and science and religion shouldn’t tread on each other’s territory.’ So, the Church is not expert on the physical universe and scientists shouldn’t claim to be expert on the moral universe. I think that’s fair. By the way, the pope has an observatory … and the modern calendar was worked out by a Vatican astronomer. [It was named in 1582] for the pope of the day, Pope Gregory XIII.

Q: NASA launched its final shuttle this summer. In what direction would you like to see the space program go?

A: I think with robotic explorers, we can cover the surface of Mars, we can dig up the ground, we can look for signs of life. Eventually, we would be able to send robots to Mars to prepare a house for astronauts if we ever get ready to send them. Long before that, we should be able to bring back samples of Mars for analysis here. We’ve already figured out how to do it more or less. The modern generation that's growing up with a computer in every crib is going to be quite comfortable with sending robots to do stuff. People still want to go into space too, though. I think a million people showed up to watch John Glenn go into space. They voted with their feet and spent something like a billion dollars of their own money to see this happen. People definitely care about space exploration.