National Post (National Edition)
After the Big Bang
Scientists say the universe is 80 million years older than thought
PARIS • New results from looking at the split-second after the Big Bang indicate the universe is 80 million years older than previously thought.
The findings released Thursday bolster a key theory called inflation, which says the universe burst from subatomic size to its now-observable expanse in a fraction of a second. The new observations from the European Space Agency’s $900-million Planck space probe appear to reinforce some predictions made decades ago solely on the basis of mathematical concepts.
“We’ve uncovered a fundamental truth of the universe,” said George Efstathiou, director of the Kavli Institute for Cosmology at the University of Cambridge who announced the Planck satellite mapping result in Paris. “There’s less stuff that we don’t understand by a tiny amount.”
“It’s a big pat on the back for our understanding of the universe,” said California Institute of Technology physicist Sean Carroll, who was not involved in the project. “In terms of describing the current universe, I think we have a right to say we’re on the right track.”
The Big Bang — the most comprehensive theory of the universe’s beginning — says the visible portion of the universe was smaller than an atom when, in a split second, it exploded, cooled and expanded faster than the speed of light.
The Planck space probe looked back at the afterglow of the Big Bang, and those results have now added about 80 million years to the universe’s age, putting it at 13.81 billion years old.
The probe, named for the German physicist Max Planck, the originator of quantum physics, also found that the cosmos is expanding a bit slower than originally thought, has a little less of that mysterious dark energy than astronomers had figured and has a tad more normal matter. But scientists say those are small changes in calculations about the universe, whose numbers are so massive.
Officials at NASA, which was also part of the experiment, said the Planck probe has provided a deeper understanding of the intricate history of the universe and its complex composition.
The Planck space telescope, launched in 2009, has spent 15 months mapping the sky, examining so-called “light” fossils and sound echoes from the Big Bang by looking at background radiation in the cosmos.
The spacecraft is expected to keep transmitting data until late 2013, when it runs out of cooling fluid.
Scientists not involved in the project said the results were comparable in scale to the announcement earlier this month by a different European physics group on a subatomic level — with the finding of the Higgs boson particle that explains mass in the universe.
“What a wonderful triumph of the mathematical approach
It’s an amazing story of discovery. The precision is breathtaking.
to describing nature,” said Brian Greene, a Columbia University physicist who was not part of the new Planck research. “It’s an amazing story of discovery.
“The precision is breathtaking. The satellite is measuring temperature variations in space — which arose from pro- cesses that took place almost 14 billion years ago — to one part in a million. Amazing.”
Mr. Efstathiou marvelled at how the Planck data was such “an extremely good match” to the theory of rapid inflation in the split-second after the Big Bang.
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 meas- urements 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,” Mr. 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, Mr. Efstathiou said.
Two inflation 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, Mr. Albrecht and Mr. Steinhardt said. That means there are places where expansion is zooming fast, with an infinite number of universes that stretch to infinity, they said.
Mr. 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.