Alan Guth
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.
If there's no limit to how big the entropy can get, then you can start anywhere, and from that starting point, you'd expect entropy to rise as the system moves to explore larger and larger regions of phase space.
The Big Bang theory says nothing about what banged, why it banged, or what happened before it banged.
Now, what space ultimately is - I should confess, I think most physicists believe - we don't yet know.
If we assume there is no maximum possible entropy for the universe, then any state can be a state of low entropy.
If you consider the universe one second after the Big Bang, the expansion rate would have to have been just right to an accuracy of 15 decimal places, or else the universe would really not work.
I'm pretty slow at writing papers.
It's not a coincidence that the Bible starts with Genesis. Most people really want to know where we came from and where everything around us came from. I like to strongly push the scientific answer. We have evidence. We no longer have to rely on stories we were told when we were young.
I'm a cosmologist. All I do is cosmology.
From a theoretical point of view, it is very hard to imagine how gravity could avoid being quantized.
When one studies the properties of atoms, one found that the reality is far stranger than anybody would have invented in the form of fiction. Particles really do have the possibility of, in some sense, being in more than one place at one time.
Space is certainly something more complicated than the average person would probably realize. Space is not just an empty background in which things happen.
Our best theory of describing space at a fundamental level is probably string theory.
My parents were not at all involved in science. In fact, neither of them went to college.
I had considered MIT a place where brilliant people came.
In high school, I was the best broad jumper on our team, and I kind of thought that when I got to MIT, I'd probably still be the best broad jumper, 'cause why do broad jumpers come to MIT? But it turned out to actually be the other way around. There was another person in my class who could jump about 3 feet further than I could.
It is rather fantastic to realize that the laws of physics can describe how everything was created in a random quantum fluctuation out of nothing, and how over the course of 15 billion years, matter could organize in such complex ways that we have human beings sitting here, talking, doing things intentionally.
If you bang two electrons together with enough energy, you produce protons. If there are no independent laws, then all the properties of protons must somehow be 'known' by the electrons. By extension, every elementary particle must carry around enough information to produce the entire universe. I find that difficult to believe.
If laws are just properties of objects, how can those laws continue to operate when the object is not really there?
It was sort of assumed, from the time I was born, really, that I would go to college. That's sort of the way that Jewish families in New Jersey handled things; that was the norm.
I think I always wanted to go into physics. What always fascinated me about science was the desire to understand what underlies it all, and I think physics is basically the study of that.
I do worry about the fact that science is becoming a slower process as society is becoming less patient.
I am not aware of any sensible theory of how classical gravity could interact with quantum matter, and I can't imagine how such a theory might work.
From the time I was a student, I think I was very confident in my raw abilities. I would think that, given a problem, I was as likely to solve it as anybody. But that's not enough in science to succeed, really.
To a theoretical physicist, there is no greater joy than to see that this curious activity we call calculation - the depositing of ink on paper, followed by throwing away the paper and depositing new ink on more paper - can actually tell us something about reality.
The idea of combining the physics of modern particle theory with cosmology was very young when I started working on cosmology.
Reformed Jews don't have to quite believe in God.
If one just tried to invent a universe on one's own, it would probably end up being a much less colorful and interesting universe than the one that we live in.
Relativity can, for instance, explain that the universe had once been clumped into a dense fireball. But it can never explain how matter actually behaved.
We don't have a solid theory of how the universe originated, but that doesn't mean we have to invoke a deity.
The question of the origin of the matter in the universe is no longer thought to be beyond the range of science - everything can be created from nothing. It is fair to say that the universe is the ultimate free lunch.Collection: Lunch
Despite its name, the big bang theory is not really a theory of a bang at all. It is really only a theory of the aftermath of a bang.Collection: Names
It’s hard to build models of inflation that don't lead to a multiverse. It’s not impossible, so I think there’s still certainly research that needs to be done. But most models of inflation do lead to a multiverse, and evidence for inflation will be pushing us in the direction of taking [the idea of a] multiverse seriously.Collection: Thinking
It's actually safe to create a universe in your basement.Collection: Safe
The recent developments in cosmology strongly suggest that the universe may be the ultimate free lunch.Collection: Lunch