We shouldn’t be obsessed with finding a theory of everything, says Lisa Randall, one of the world’s most prominent theoretical physicists. Her recent books are Knocking on Heaven’s Door and Higgs Discovery: The Power of Empty Space.
Valerie Jamieson and Richard Webb: Doesn’t every physicist dream of one neat theory of everything?
Lisa Randall: There are lots of physicists! I don’t think about a theory of everything when I do my research. And even if we knew the ultimate underlying theory, how are you going to explain the fact that we’re sitting here? Solving string theory won’t tell us how humanity was born.
VJ & RW: So is a theory of everything a myth?
LR: It’s not that it’s a fallacy. It’s one objective that will inspire progress. I just think the idea that we will ever get there is a little bit challenging.
VJ & RW: But isn’t beautiful mathematics supposed to lead us to the truth?
LR: You have to be careful when you use beauty as a guide. There are many theories people didn’t think were beautiful at the time but did find beautiful later—and vice versa. I think simplicity is a good guide: The more economical a theory, the better.
VJ & RW: Is it a problem, then, that our best theories of particle physics and cosmology are so messy?
LR: We’re trying to describe the universe from 1027 meters down to 10-35 meters, so it’s not surprising there are lots of ingredients. The idea that the stuff we’re made of should be everything seems quite preposterous. Dark matter and dark energy—these are not crazy ingredients we’re adding.