Scientists who watched stars explode in faraway galaxies and deduced that the universe was expanding at an ever-faster rate have won the Nobel Prize in Physics.
The discovery in the late 1990s meant textbooks had to be rewritten and forced researchers to consider a universe of stars and planets that is being torn apart by a mysterious force that counteracts gravity.
The nature of the force that drives the growth of the cosmos is so mysterious that scientists named it "dark energy". It is thought to make up more than 70% of the universe.
Half of the 10 million Swedish kronor (£934,000) prize money went to the US physicist Saul Perlmutter, 52, and the other half to two members of a competing team that conducted similar work, the US-born researcher Brian Schmidt, 44, who is based in Australia, and another US scientist, Adam Riess, aged 42.
The award was greeted with widespread approval from scientists, though some argued that by recognising only three physicists, the prize distorted how the research was done.
Two teams, headed by Perlmutter and Schmidt, raced each other to make exquisitely precise observations of distant supernovae - or exploding stars - and announced their controversial results within weeks of each other in 1998. Both found that instead of the light from 50 dying stars becoming brighter, it was fading.
This suggested that the expansion of the universe was not slowing down as expected, but accelerating. The result was a shock to the physics community because, overwhelmingly, cosmologists expected gravity to slow the expansion of the cosmos and even orchestrate its demise in a cosmic crunch at the end of time.
"We expected to find that the universe was slowing down, because gravity would attract everything to everything else, but instead we found it was speeding up. But this is what scientists look for: you discover something new and it opens up a whole new world of opportunities and mystery that we can then try to explore," Perlmutter told the Guardian.
"When we first presented the results, we really had to think hard, are we ready to show people something that is so counterintuitive? We finally came to the conclusion that we had done all the right crosschecks and we had to go ahead and show people," Perlmutter added.
Perlmutter, who is based at the University of California, Berkeley, heard he had won the Nobel prize at around 2.45am on Tuesday morning when a Swedish journalist called. The Nobel committee had failed to contact him because they had an old mobile phone number.
Brian Schmidt at the Australian National University in Weston Creek told the Guardian that he wrote to his team when the result held up under intense scrutiny. "I said that's the way science is. We are not being good scientists if we prejudge the universe. The universe does what it wants, not what we want it to do," Schmidt said.
"Scientists must stand up and tell people what they find and we suffer the consequences if we make a mistake. We are seeing this in action right now with faster-than-light neutrinos. People are very sceptical of that, but those guys have done what they can to make it go away."
Lord Rees, the astronomer royal, said the prize recognised an "important and surprising discovery", that empty space contains energy that causes cosmic expansion to accelerate. "It will be a long time before theorists understand this force - it is part of the bedrock nature of space and time," he said.
But Rees said the award failed to acknowledge work done by others in the two teams: "This is one of the increasingly frequent instances when the Nobel committee is damagingly constrained by its tradition that a prize can't be shared between more than three individuals. The key papers recognised by this award were authored by two groups, each containing a dozen or so scientists. It would have been fairer, and would send a less distorted message about how this kind of science is actually done, if the award had been made collectively to all members of the two groups."
Schmidt said he and the other prize recipients saw the prize as a celebration of the work done by all of the team members. "The Nobel prize is the Nobel prize and it has a great impact because of the way it is done. In this case I would love to share it with my colleagues and I will be inviting my colleagues to Stockholm to celebrate it with me even if they are not officially on the award," he said.
Pedro Ferreira, a cosmologist at Oxford University, said the prize was "wonderful" news. "You have to put this into perspective. Only a few decades ago, cosmology was exciting, but quite esoteric. People could make stuff up and get away with it. Now, because of endeavours such as the supernovae observations, we can make hard, accurate statements about the cosmos, we can really say precise things about the state of the universe. And it is only going to get better. It is a truly great time to be working in the field," he said.
The Neutrino faster than light thing, however, has a ways to go. My Astronomy professor pointed out to me that light 'apparently' travels faster than light when it is refracted by the first surface of an optical flat, then continues at light speed when leaving the last surface. Otherwise, if Einstein is correct, and the observation holds, the only explanation is a similar phenomenon or time travel.