Alan Guth on Space

ALAN GUTH ON SPACE

Posted: November 10, 2011

Physicists have a hard time answering questions as basic as something like "What is space?" Space is certainly something more complicated than the average person would probably realize. Space is not just an empty background in which things happen. In the context of general relativity, space almost is a substance. It can bend and twist and stretch, and probably the best way to think about space is to just kind of imagine a big piece of rubber that you can pull and twist and bend. And that's a pretty good model for what space is like in the context of general relativity.

Now, what space ultimately is—I should confess, I think most physicists believe—we don't yet know. Our best theory of describing space at a fundamental level is probably string theory. But exactly how space even emerges from string theory is something that people don't understand very well. So I think if you come back and ask the question "What is space?" 10 years from now, you'll get a very different answer.

AUDIO

Produced by

David Levin

Original interview by

Rush DeNooyer

IMAGE

(Alan Guth)

© WGBH Educational Foundation 2011

Major funding for "The Fabric of the Cosmos" is provided by the National Science Foundation and the Alfred P. Sloan Foundation.

Additional funding for this program is provided by the Arthur Vining Davis Foundations.