The following questions and answers were compiled by Wired from John Mather '68's "Ask Me Anything" (AMA) chat on Reddit.

Redditor: Why is looking at the stars a scientifically meaningful thing to do?
John C Mather: Looking at the stars was the beginning of quantitative science, and still propels new advances in technology as well as fundamental discoveries about our history and our place in the universe. People want to know how we got here, are we alone, and where we are going. Astronomy answers part of that.

What is the most commonly-held misconception people have about space?
I think people have a really hard time grasping how empty outer space is, in the sense of immense distances between objects, and immense time spent going from one to another. There's a lot of talk about space aliens, as though it were physically possible for them to get here from somewhere else, and (sorry to say this) talk about human travel out of the solar system. We just don't live long enough to do that.

Where do you see your field of research in 20 years?
I think we will be swimming in oceans of pictures and data and new discoveries from JWST and other new equipment. Our ground-based telescopes will be about three times larger than they are today and some of them may have the capability to directly image exoplanets using extreme adaptive optics.

What do you think is the most exciting thing that the JWST can show to us?
We don't know how many planetary systems might be hospitable to life, but JWST could tell whether some Earth-like planets have enough water to have oceans.

Of all the different scientific fields, why did you choose physics?
It was the one with the greatest unsolved problems! When I was a student, we didn't know much about the elementary particles, but we had a chance to learn so much. Then, it turned out I had a good mind for physics and math, and it was a lot of fun learning how to think about the mysteries, like relativity and quantum mechanics.

Did your Nobel Prize-winning work come about by accident, and was winning it a surprise?
The Nobel work came by a roundabout path. My thesis project at Berkeley was chosen because it was exciting and I liked the professors. Then it failed to function and I thought I would give up on the cosmic microwave background radiation. Then, I was a postdoc doing radio astronomy and Nasa asked for satellite proposals; that was 1974. I said, my thesis project failed, but it should have been done in outer space. So we wrote a proposal and it was chosen.

About the Nobel, a lot of people thought the COBE [Cosmic Background Explorer Satellite] was Nobel-quality work, but I thought, the competition is fierce, and only people like Einstein get on the list. So it was a lovely surprise!

What's the next big step in terms of space research?
Good question! The James Webb Space Telescope is the next big thing in astrophysics, and the Decadal survey produced by the National Academy of Sciences says the next thing after that should be the WFIRST, an wide field infrared survey telescope. Now that the NRO has donated two sets of optics to NASA, perhaps one set will become WFIRST. We also have in mind plans for the next great X-ray observatory, and a search for gravitational waves using a space interferometer. I think we have at least a century of amazing ideas to carry out.

John Mather '68 graduated from Swarthmore College with a major in physics and minors in mathematics and astronomy. He recieved his Ph.D. in physics from the University of California at Berkeley. He was awarded an honorary Doctor of Science Degree from Swarthmore in 1994 and is a member of the National Academy of Sciences. In addition to winning the Nobel Prize in Physics in 2006, he has recieved a multitude of awards from organizations including NASA, the American Astronomical Society and the American Institute of Physics, and the Optical Society of America.