Or why you’re suddenly reading about “inflation” in a story about astrophysics? And just what are “cosmic ripples”?
Astrophysicist Mordecai-Mark Mac Low breaks down the exciting headlines.
First, the findings.
As reported in The New York Times, an international team of researchers announced they had detected direct evidence of the universe’s earliest expansion in a tiny fraction of a second after the Big Bang.
What kind of evidence?
In the first instants after the Big Bang, the observable universe was minute and as dense as the interior of a black hole. “Then, for a brief moment after the Big Bang, the universe appears to have expanded at astonishing velocity,” explains Dr. Mac Low. Theorists call this phenomenon “inflation.”
This violent expansion, researchers hypothesized, formed the “ripples” that recently made international headlines—gravitational waves that still permeate the universe today. Researchers using the South Pole observatory data reported the first direct evidence of these gravitational waves.
They gathered the evidence by making long-term observations of the Cosmic Microwave Background, the remaining light of the Big Bang, which was emitted about 380,000 years after the formation of the universe. The researchers were able to see that the light had been polarized in a pattern that could only have been produced by the hypothesized gravitational waves. “The light making up the cosmic background radiation was distorted by a bath of gravitational waves left over from inflation,” explains Mac Low.
Learn more about the cosmic microwave background in this video with Dr. Mac Low.
What’s next?
Later this year, other teams of researchers, including those using data from the European Space Agency/NASA Planck satellite, may confirm these findings from the earliest moments of the universe. “Before this work, the earliest period we had direct evidence for was a few minutes after the Big Bang,” says Dr. Mac Low. “Now we have data from the first 10-36 seconds.”