Right after the universe was born in the Big Bang it threw an epic "temper tantrum."

The universe rapidly grew from its "birth weight" of smaller than an atomic nucleus to an unobservable size, a University of Minnesota news release reported.

This period of expansion is dubbed the inflation epoch; the event generated particles and gravitational waves which created "gigantic ripples in the very fabric of space," the news release reported. This idea is called the theory of inflation; the theory had been extremely hard to prove up until this point.

The inflation theory predicts gravitational waves will leave their "signature" on the cosmic microwave background (CMB) radiation, a form of light left over from the Big Bang's afterglow. The researchers were able to detect this imprint using the BICEP2 telescope at the National Science Foundation's South Pole Station.

 "It's the smoking gun for inflation," University of Minnesota's Clem Pryke, an associate professor of physics said in a news release. "There's no other explanation for the gravitational waves [whose imprint] we're seeing."

The Big Bang is believed to have occurred 13.7 billion years ago, with inflation following immediately afterwards. It is believed to have started between 10 and 32 seconds after the Big Bang and lasted for only the same amount of time. In this short period of time it produced high-amplitude gravitational waves.

About 380,000 years later the universe had cooled down, allowing true atoms to condense and light to move around freely. That light has been stretched to microwave wavelengths, but can still be seen today as the CMB.

During this period of light expansion gravitational waves created a "curling pattern of polarization on the CMB," the news release reported. This pattern is called "B-mode" may be a "smoking gun" for ancient gravitational waves.

"We were looking for a needle in a haystack, but instead we found a crowbar," Pryke said.