WAVES COULD BE BIG BANG’S SMOKING GUN
Gravitational waves hailed as ‘smoking gun’
Scientists at the South Pole used special telescopes to detect primordial gravitational waves — ripples in the fabric of space and time — which hold clues to the nature of the universe. The ripples have never been seen directly until now.
In an achievement hailed as astounding, scientists have detected ripples made in the fabric of the universe just after the Big Bang, providing definitive evidence that the universe underwent a fast and incomprehensibly massive growth spurt in its earliest infancy.
If the findings are confirmed, they could very well earn the Nobel Prize for the team behind the research, says astrophysicist Xavier Siemens of the University of Wisconsin-Milwaukee.
“This is an amazing discovery,” he said. To find such strong evidence of these waves “is really just astounding.”
If the data are correct, “it’s a really profound discovery for cosmology,” says Cornell University cosmologist Rachel Bean. “It’s a phenomenal announcement.”
In the thinnest sliver of a second after the Big Bang, the universe was smaller than the end of your pinky finger. To explain its current state, scientists have posited an event called “inflation,” when space expanded violently, and almost instantaneously, by roughly 100 trillion trillion times, said cosmologist Daniel Baumann of the University of Cambridge. That should have magnified tiny ripples in the universe called primordial gravitational waves, which in turn left a stamp on light created some 13.5 billion years ago.
That light still pervades the cosmos today as a faint glow in- visible to the naked eye called the cosmic microwave background. A team of U.S. scientists announced Monday that they’d used a telescope in Antarctica to detect a telltale “curl” in the microwaves’ orientation — a pattern that’s the fingerprint of gravitational waves.
Albert Einstein predicted the existence of such ripples a century ago but thought they might be too faint to be detected.
Overturning expectations, the researchers said the evidence for the patterned microwaves was much less subtle than had been predicted.
“This has been like looking for a needle in a haystack,” the University of Minnesota’s Clem Pryke, a co-leader of the BICEP team, said in a statement, “but instead we found a crowbar.”
The findings are being hailed as the “smoking gun” of the inflation theory, which some scientists have scorned as inadequate. These results should help remove the last traces of doubt that inflation is the best way to explain the current status of the universe, scientists said.
Until now, “there was always this nagging doubt in me” about inflation, Baumann said. But “once (the new finding) is con- firmed, I do believe it’s the smoking gun.”
Outside scientists are eager to see the new results confirmed by separate experiments.
“Having confirmation is going to be important,” Siemens said. “But … these are very careful and smart people that produced these results.”
The results, from what’s known as the BICEP2 experiment, also provide the first data on what space was like at an extremely early age. Until now there had been lots of theories on the traits of the infant universe, but no direct evidence. Scientists had long hoped that primordial gravitational waves would allow such insights.
“That’s always been the promise,” says experimental physicist Gregory Harry of American University, also a member of the LIGO collaboration, a group of scientists searching for gravitational waves.
“Here BICEP has done it. They’ve got data from the very earliest moment in the universe.”
The announcement is “extraordinarily exciting for the cosmology community,” Cornell’s Bean said. “It sends out waves, and not just gravitational waves.”