Size of a Football

I loved the opening sentence of this article from The Times because while I find it completely impossible to imagine something as big as the universe being 'infinitely small', I can relate to the fact that it was once the size of a football - only to expand 100 trillion trillion times in the space of an instant.

Now that is mind bending stuff and it's amazing that scientists are able to predict such things and then go on, often at a much later date, to show that they are actually true.  


Spectacular discovery provides new evidence of Big Bang theory for universe

The sun sets behind the BICEP2 telescope at the South Pole which was used for research on the Big Bang AP

Tom Whipple - The Times

In the beginning, the Universe was infinitesimally small. An infinitesimally small period of time later, it was just finitely small, a bit less than a football.

This single event, in which space ripped itself apart to expand by 100 trillion trillion times in an instant, is arguably the most significant moment in history, and today scientists said they had at last proved that it happened.

It is this period of “inflation” a billion billion billion millionths of a second after the big bang that led to galaxies, planets and people. But while theories have been posited for the shape of our universe, until now no one had evidence.

Today, scientists working at an observatory in the South Pole said they had found the telltale signature that shows inflation did occur. They spotted a change in the polarisation of light they said could only have been caused by gravitational waves from the dawn of time, which themselves could only be caused by a phenomenal expansion in the Universe.

“The implications for this detection stagger the mind,” said Professor Jamie Bock from Nasa.

Professor Avi Loeb from Harvard said: “This work offers new insights into our most basic questions: Why do we exist? How did the universe begin?”

Even though it requires verification from other laboratories, it is a measure of the significance of the discovery that it was barely remarked upon that it also helped to prove the existence of gravitational waves, the last great untested hypothesis of Einstein.

Without inflation, everything would be very different. While the big bang theory can explain our expanding Universe, it cannot explain its structure, in particular the way matter is distributed. Inflation was posited as a way of explaining a more uniform universe in which galaxies could exist.

The researchers had thought that spotting this effect would be difficult. When they saw the signal, it was stronger than anyone had expected. “This has been like looking for a needle in a haystack, but instead we found a crowbar,” said Professor Clem Pryke, from the University of Minnesota.

Dr Andrew Pontzen, from Oxford University, said it was a spectacular confirmation of previous theories. “The remarkable thing about the discovery is that it is telling us we can understand physics at a million million times higher energies than the Large Hadron Collider in Cern can reach,” he said.

“This is the most direct evidence for this you can hope for now. The amazing thing, the jaw-dropping thing, is that there are two incredibly important discoveries in one. It is also the most direct evidence yet that gravitational waves, an aspect of Einstein’s theory of gravity, exist.”

The theory of inflation was developed 30 years ago by physicist Andrei Linde, among others. Today, a video was released by Stanford University in which Professor Chao-Lin Kuo, one of the team who made the discovery, knocked on Professor Linde’s door to tell him the news.

“It’s 5 sigma at point 2, as clear as day,” said Professor Kuo.

It was all Professor Linde needed to hear. “We see the face of the big bang. If this is true, this is a moment of understanding of a nature of such magnitude that it overwhelms,” he said.

Dr Chris Lintott, from Oxford University, said: “If you were going to write a one sentence history of the Universe, it would be about inflation. The most important thing that ever happened was the Universe almost inexplicably grew. Our universe would be a much more boring place if this did not happen. Up until now, though, there was no evidence for this.

He added: “If inflation is real then our observable bit of the universe can only be a tiny, tiny fraction of the whole. Even if our marvellous species has worked out how it all happened, this should also make us feel a little insignificant.”