London, Feb 20 : An extraordinarily large number that keeps on showing whenever the analysis of dark energy is done, could hold the key to solving many mysteries in the Universe.
According to a report in Nature News, the number - 10122, first turned up when, more than a decade ago, physicists discovered that the expanding Universe is accelerating. his led scientists to determine that there is a force that opposes gravity on very large scales, which physicists call dark energy. It is quantified by a parameter called the cosmological constant.
One interpretation of dark energy is that it results from the energy of empty space, called vacuum energy.
The laws of quantum physics imply that empty space is not empty at all, but filled with particles popping in and out of existence. This particle 'fizz' should push objects apart, just as dark energy seems to require. But the theoretical value of this energy is immense - so huge that it should blow atoms apart, rather than just causing the Universe to accelerate.
Physicists think that some unknown force nearly perfectly cancels out the vacuum energy, leaving only the amount seen as dark energy to push things apart. This cancellation is imperfect to a large margin: the unknwon 'energy' differs from the vacuum energy by just one part in 10122.
According to Scott Funkhouser of the Military College of South Carolina in Charleston, US, this is not the only appearance of this vast number among the parameters of the Universe. He lists five other instances in which the ratios between various cosmic quantities turn out to be equal to 10122, give or take a factor of ten.
For example, the ratio of the mass of the observable Universe to that of the smallest possible 'quantum' of mass is about 6x10121. And the number of ways in which the particles of the current Universe can be arranged throughout space (a measure of entropy) is 2.5x10122.
"If you take the basic parameters of the Universe there are only so many ways you can put them together to make 'pure numbers' with no units," said Funkhouser.
So the fact that even a handful of these give ratios that are so huge and yet so similar seems significant.
"It is unlikely for chance alone to be responsible for generating so many pure numbers from just several fundamental parameters," said Funkhouser.
"It is remarkable enough that the parameters of nature should somehow produce one large-number coincidence," he added.