Washington, October 1 : A new radical theory has suggested that Earth may be trapped in an abnormal bubble of space-time that is particularly devoid of matter.
According to a report in Fox News, scientists said that this condition could account for the apparent acceleration of the universe's expansion, for which dark energy currently is the leading explanation.
Dark energy is the name given to the hypothetical force that could be drawing all the stuff in the universe outward at an ever-increasing rate.
Current thinking is that 74 percent of the universe could be made up of this exotic dark energy, with another 21 percent being dark matter, and normal matter comprising the remaining 5 percent.
Until now, there has been no good way to choose between dark energy or the void explanation, but the new study outlines a potential test of the bubble scenario.
According to the study, if we were in an unusually sparse area of the universe, then things could look farther away than they really are and there would be no need to rely on dark energy as an explanation for certain astronomical observations.
"If we lived in a very large under-density, then the space-time itself wouldn't be accelerating," said researcher Timothy Clifton of Oxford University in England. "It would just be that the observations, if interpreted in the usual way, would look like they were," he added.
Scientists first detected the acceleration by noting that distant supernovae seemed to be moving away from us faster than they should be.
One type of supernova (called Type Ia) is a useful distance indicator, because the explosions always have the same intrinsic brightness.
Since light gets dimmer the farther it travels, that means that when the supernovae appear faint to us, they are far away, and when they appear bright, they are closer in.
But if we happened to be in a portion of the universe with less matter in it than normal, then the space-time around us would be different than it is outside, because matter warps space-time.
Light travelling from supernovae outside our bubble would appear dimmer, because the light would diverge more than we would expect once it got inside our void.
"This idea that we live in a void would really be a statement that we live in a special place," said Clifton.
"The regular cosmological model is based on the idea that where we live is a typical place in the universe. This would be a contradiction to the Copernican principle," he added.