The Meaning of Inflation

When we hear about inflation, we naturally assume it means that prices are going up. Because that’s what economists have taught us to think. But talk to a physicist, and you will soon learn that inflation has an entirely different meaning.

Inflation, for physicists, is an extension of the Big Bang theory. And the reason it is important is that it helps answer some of the difficult questions the theory raises, like how is it possible that the Universe has an even temperature?

If you’re like me, you probably learned about the Big Bang theory in school. And if you asked me what it meant just a few weeks ago, I would have confidently told you that it is the scientific explanation for how the Universe began.

But if you asked me today, I would start by telling you that the Big Bang theory is still a theory. And as Stephen Hawking puts it, a theory is just a model of the universe.

“Any physical theory is only provisional, in the sense that it is only a hypothesis: you can never prove it.” – Stephen Hawking

So when astronomers at the South Pole discovered faint spiral patterns from the polarization of microwave radiation left over from the Big Bang, it generated a lot of excitement in the scientific community.

In Ripples From the Big Bang, Dennis Overbye explains how the team, led by John M. Kovac of the Harvard-Smithsonian Center for Astrophysics, found evidence to support the theory of inflation, which explains how the universe expanded so uniformly and so quickly in the instant after the Big Bang 13.8 billion years ago.

Overbye says that if the chain of evidence and reasoning holds up, it could lend support to the fervently hoped-for unification theory of Einstein’s gravity, which shapes the universe, and quantum theory, which governs the behavior of atoms inside it. And, he says, the discovery suggests that gravity, too, might ultimately be described by the same weird quantum rules as those that describe the other forces.

Photo credit: NASA

Photo credit: NASA

Don’t miss the graphic in this article that really helps explain it all.

[UPDATE: In a remarkable coincidence (spooky entanglement?) I just read an article in LiveScience that said three physicists were awarded the prestigious Kavli Prize in Astrophysics today (May 29) for their work on cosmic inflation. Congratulations to Alan Guth of MIT, Andrei Linde of Stanford University, and Alexei Starobinsky of the Landau Institute for Theoretical Physics in Russia.]

–DJ