Inflation tries to explain some nagging problems left over from the Big Bang, which formed the universe in a sudden burst. Other space probes have shown that the geometry of the universe is predominantly flat, but the Big Bang said it should curve with time. Another problem was that opposite ends of space are so far apart that they could never have been near each other under the normal laws of physics, but early cosmic microwave background measurements show they must have been in contact.
So a few physicists more than 30 years ago came up with a theory to explain this: Inflation. That says the universe swelled tremendously, going "from subatomic size to something as large as the observable universe in a fraction of a second," Greene said.
Planck shows that inflation is proving to be the best explanation for what happened just after the Big Bang, but that doesn't mean it is the right theory or that it even comes close to resolving all the outstanding problems in the theory, Efstathiou said.
There was an odd spike in some of the Planck temperature data that hinted at a preferred direction or axis that seemed to fit nicely with the angle of our solar system, which shouldn't be, he said.
But overall, Planck's results touched on mysteries of the universe that have already garnered scientists three different Nobel prizes. Twice before scientists studying cosmic background radiation have won a Nobel Prize - in 1978 and 2006 - and other work on dark energy won the Nobel in 2011.
At the press conference, Efstathiou said the pioneers of inflation theory should start thinking about their own Nobel prizes. Two of those theorists - Paul Steinhardt of Princeton and Andreas Albrecht of University of California Davis - said before the announcement that they were sort of hoping that their inflation theory would not be bolstered.
That's because taking inflation a step further leads to a sticky situation: An infinite number of universes.
To make inflation work, that split-second of expansion may not stop elsewhere like it does in the observable universe, Albrecht and Steinhardt said. That means there are places where expansion is zooming fast, with an infinite number of universes that stretch to infinity, they said.
Steinhardt dismissed any talk of a Nobel.
"This is about how humans figure out how the universe works and where it's going," Steinhardt said Thursday. "And it's kind of a raucous time at the moment."
Efstathiou said the Planck results ultimately could give rise to entirely new fields of physics - and some unresolvable oddities in explaining the cosmos.
"You can get very, very strange answers to problems when you start thinking about what different observers might see in different universes," he said.