In a potentially stunning new finding, astronomers say that they have seen evidence supporting a key element in the Big Bang theory: a hypothesized period of exponential expansion of the universe known as "inflation" — or, what one researcher calls, "the bang of the big bang." Inflation is believed to have happened in the early slivers of the second during which the universe began, and researchers now say that they have seen the first direct evidence of this expansion. "These results are not only a smoking gun for inflation," Harvard astronomer Avi Loeb says in a statement, "they also tell us when inflation took place and how powerful the process was."

The evidence, the researchers say, is a signal left by ancient gravitational waves that would have marked the universe as a result of the expansion. "Detecting this signal is one of the most important goals in cosmology today," John Kovac, leader of the collaboration between the Harvard-Smithsonian Center for Astrophysics and the BICEP2 telescope that made the findings, says in a statement. The signal they detected, known as B-mode polarization, was found using a small telescope in the South Pole and appeared as a curl in the cosmic radiation left over from the Big Bang.

Critically, this would also be the first imagery of gravitational waves. As Nature reports, that would make it the first evidence linking gravity to quantum mechanics, which currently explains each of the other fundamental forces. It's theorized that these forces were all combined in the earliest measurable phases of the Big Bang.

"We are convinced by all the studies we've done that this signal is real," researcher Clem Pryke, of the University of Minnesota, said during a presentation discussing the findings. "The most reasonable interpretation of this signal is that it is gravity waves ... and that those gravity waves come from the very tiny tiny fraction of a second just after the beginning." The researchers' findings still have to be confirmed by others, and Pryke says that many looking for the same gravitational signals are already in the works. "They will be confirming our results," he said, pausing to joke, "we hope."

Update: Scientists behind major theories don't necessarily expect to see them confirmed in their lifetime, but today, that may have happened for the physicists behind the theory of inflation. To celebrate, collaborating researcher and Stanford professor Chao-Lin Kuo went in person to surprise Andrei Linde, a major contributor to the theory after its introduction in 1980, with some champagne and news that evidence had been discovered supporting his work. While Kuo's quick delivery of the news may be incomprehensible to most of us, Linde immediately recognizes and is stunned by what he's hearing. "If this is true, it is an understanding of nature of such a magnitude that it just overwhelms," Linde says afterward. "Let's just hope that it is not a trick."