Features

Dr. John Mather, Chief Scientist for the Science Mission Directorate

NASA Headquarters, Washington, DC

ImageUsing NASA’s Cosmic Background Explorer (COBE) satellite to measure microwaves and infrared light that originated with the formation of the universe, Dr. John C. Mather helped verify the validity of the Big Bang theory. Recently named to head up the Office of the Chief Scientist for the Science Mission Directorate at NASA Headquarters in Washington, DC, Dr. Mather was a co-recipient of the 2006 Nobel Prize in Physics.

NASA Tech Briefs: Why don’t you start out by telling us a little bit about your background and what led you to pursue a career at NASA.

Dr. John Mather: Okay. I finished my graduate school at Berkeley measuring the cosmic microwave background radiation from the Big Bang in 1974. That experiment was difficult to do, so I thought I’d try radio astronomy and I got a post-doctoral position at NASA Laboratory, the Goddard Institute for Space Studies in New York City. In that same year, NASA issued an A.O. (Announcement of Opportunity) for satellite proposals and I told my post-doctoral advisor, Patrick Thaddeus, that my thesis project would’ve been better in space. So he said, “Get together a team and call up these people to write a proposal.” That was what turned into the COBE satellite.

NTB: The COBE satellite, which stands for “Cosmic Background Explorer,” was designed to study radiation patterns from the first few moments after the universe was formed. Tell us about your involvement with that project.

Dr. Mather: Well, I was the project’s initiator, from the conversation I had with my post-doctoral advisor. I was one of the leaders in writing the first proposal. In 1976, I moved to NASA’s Goddard Space Flight Center in Greenbelt, MD, to, I hoped, become the Study Scientist for the project, which I did. I was also chosen by Headquarters to be the principal investigator for one of the three instruments, which is the one basically that’s the follow-on to my thesis project.

NTB: One of the things you learned from that project is that all of the universe’s radiant energy was released within the first year after the Big Bang occurred, correct? Why is that significant?

Dr. Mather: Well, it means that the Big Bang theory is an excellent description of the early universe and that it was all pretty simple. We had imagined that maybe it was possible that the fundamental nature of matter is a little bit weird and that, say, elementary particles like protons are unstable and would decay and liberate energy after the Big Bang. That’s an example of a wild idea that turned out not to be true. But there were plenty of other wild ideas and bad theories to explain the bad data that had been taken before we flew the COBE satellite.

NTB: One of the phenomena that the COBE satellite uncovered was slight temperature variations in the light detected from the early universe. These variations, it’s claimed, indicate density differences that eventually resulted in stars, planets, and the galaxies. Can you explain, in simple terms, how that whole relationship works? How do temperature differences indicate the formation of stars and planets?