No matter how impressed or intrigued you were to hear that researchers had found the "smoking gun" for the universe's incredible Big Bang expansion, your reaction cannot compare to that of Andrei Linde.

The Stanford University physicist appeared overwhelmed and on the verge of tears after learning that a team of astronomers had detected the signature of primordial gravitational waves — a key prediction of the theory of cosmic inflation, which Linde helped refine in the early 1980s after it was originally proposed by Alan Guth.

Inflation is the mysterious force that blew up the scale of the infant universe from sub-microscopic to gargantuan in a fraction of a second. <a href="http://www.space.com/25075-cosmic-inflation-universe-expansion-big-bang-infographic.html">See how cosmic inflation theory for the Big Bang and universe's expansion works in this Space.com infographic</a>.
Inflation is the mysterious force that blew up the scale of the infant universe from sub-microscopic to gargantuan in a fraction of a second. See how cosmic inflation theory for the Big Bang and universe's expansion works in this Space.com infographic.
Credit: By Karl Tate, Infographics Artist

Study team member Chao-Lin Kuo, also of Stanford, brought the big news to Linde's front door, and a camera crew caught Linde's reaction on video.

"We didn't expect anybody," Linde said in a video released Monday (March 17) by Stanford. "Renata [Kallosh, Linde's wife] said, 'It's probably some kind of delivery — did you order anything?' Yeah, I ordered it 30 years ago. Finally, it arrived!"

On Monday, a team of astronomers led by John Kovac of the Harvard-Smithsonian Center for Astrophysics announced that they had found direct evidence of gravitational waves in the cosmic microwave background, the ancient light that began saturating the universe about 380,000 years after the Big Bang.

If the new results hold up, they confirm that the universe did indeed undergo a period of incredible inflation just after the Big Bang, exploding from mere quantum fluctuations into something of macroscopic size in just a few tiny fractions of a second.

"If this is true, this is a moment of understanding of nature of such a magnitude that it just overwhelms," Linde said.

"I always leave with this feeling — what if I'm tricked? What if I believe in this just because it is beautiful?" he added. "So this is really helpful, to have events like that — it's really, really helpful."

Then Linde turned to Kuo: "Thank you so much for doing it."

Follow Mike Wall on Twitter @michaeldwall and Google+. Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.