The Man Who Inflated the Universe

Working late one night, Alan Guth struck upon a solution to the birth of the cosmos. Until then, he’d had trouble holding down a job.

ALAN GUTH still finds it amazing that he can understand anything about the first few moments of the Big Bang. But he shouldn’t — he was there.

About 13.8 billion years ago, when the universe was a hundredth of a billionth of a trillionth of a trillionth of a second old, it underwent an incredible growth spurt, doubling in size more than 60 times in a split second. This cosmic fireball quickly slowed, then — after about 380,000 years — cooled enough for electrons to combine with nuclei and form atoms. This liberated photons of light from surrounding interference and made the universe suddenly visible.

Somewhere between 150 million and 1 billion years later, gravity drove enough clumps of gas to collapse inward that they formed the first stars. The intense heat and pressure deep within these stars acted like thermonuclear furnaces, converting the only matter that existed — hydrogen, helium and lithium — into heavier elements like carbon, iron and nickel.

And Alan Guth.

Not the astrophysicist himself, who sits before me in a checked blue shirt, light green chinos and…