'Puny human brains' and the beginning of time

Scientists released new evidence Monday that showed cosmic inflation, proof of the first moments of time after the Big Bang. Clem Pryke, an experimental cosmologist at the University of Minnesota and one of the principal investigators on the team that made the discovery, joined The Daily Circuit Wednesday to discuss the research. Highlights from that conversation:

What the scientists found:
"Our telescope is a specialized radio telescope at the National Science Foundation's South Pole research facility. What we did was make a very high-sensitivity map of a small region of the sky in polarization. So we're measuring the polarization of the cosmic microwave background which is light which comes to us from about 400,000 years after the beginning ... What we see written in that pattern from 400,000 years is the kind of telltale signature of gravitational waves which were launched into the fabric of space-time in that very first instant of creation."

What moves faster than light?
"The expansion of space-time itself is effectively faster than the speed of light. As we know from Einstein's theory, nothing can move through space faster than the speed of light, but in the general relativity theory it's OK for the fabric of space-time itself to expand faster than the speed of light. So these are mind-boggling ideas. But what that kind of hyper-expansion does is, it launches disturbances of all kinds into the fabric of space-time, including these gravitational waves, which we can then see the imprint of a little later, at 400,000 years."

The quest for a unified theory:
"You know the universe is expanding. And as it expands, it cools. So logically if you go back in time it must have been hotter and denser. And that's what the Hot Big Bang Theory is. And this result is kind of pushing that to its ultimate conclusion, winding the clock back to the point where the energy scale was fantastically high. In fact so high that the four forces of nature, which are distinct in the contemporary universe, were hypothesized to be unified together, to be merged together. And so at that energy scale, quantum mechanics and general relativity, the theories of the very small and the very large, were actually merged together into a grand, unified theory — we think. Right? So people have been questing for such a theory for a long time, and even the smartest people alive have not managed to come up with one so far. But this result has implications for that quest, because it gives us direct insight into the physics of this fantastically high energy scale."

'Our puny human brains':
"The Big Bang is the creation of space-time. It's an explosion of space-time, if you want to think about it that way. It's unfortunate that our puny human brains are three-dimensional, and we can't think in this warped four-dimensional space-time. But people always want to think ... if it's an explosion, it must have been exploding into something, right? And that's because we're locked into this three-dimensional thinking that we evolved on the plains of Africa because it was perfectly appropriate."

The case for multiple universes:
"The inflation theory [describes] a little subatomic speck of space-time which hyperinflates. And so you can ask, Well, what space-time was that speck preexisting in? And it is possible to think about there being some pre-space, which had many bubbles, some of which inflated a lot, some of which inflated a little. And these are called multiverse theories. Now personally, as an experimentalist, I don't want to hear about any theory that has no testable consequences in our universe. Because it seems to me the word 'universe' means 'that which we can observe,' and if we can't observe it, it's not really science. It's metaphysics. But it is possible that there were a multitude of universes, of different inflationary bubbles, and we're just one of them. ... I don't like these theories, so unfortunately for me, it actually does give them greater credence. Because if inflation happened in one subatomic speck of space — one quantum fluctuation blew up — then why not others, right?"

LEARN MORE ABOUT THE DISCOVERY:

• Scientists Discover Major Evidence for Big Bang
Evidence was found in detecting the gravitational waves or ripples in space-time that were put forth nearly 14 billion years ago when the universe burst into existence.. (The Takeaway)

• A big-bang theory gets a big boost: Evidence that vast cosmos was created in split second
A team of astronomers led by John Kovac of the Harvard-Smithsonian Center for Astrophysics announced that it had detected ripples from gravitational waves created in a violent inflationary event at the dawn of time. "We're very excited to present our results because they seem to match the prediction of the theory so closely," Kovac said in an interview. "But it's the case that science can never actually prove a theory to be true. There could always be an alternative explanation that we haven't been clever enough to think of." (Washington Post)

• Space Ripples Reveal Big Bang's Smoking Gun
If corroborated, Dr. Kovac's work will stand as a landmark in science comparable to the recent discovery of dark energy pushing the universe apart, or of the Big Bang itself. It would open vast realms of time and space and energy to science and speculation. (New York Times)