Remember a little thing called the space-time continuum? Well what if the time part of the equation was literally running out? New evidence is suggesting that time is slowly disappearing from our universe, and will one day vanish completely. This radical theory may explain a cosmological mystery that has baffled scientists for years.
Scientists previously have measured the light from distant exploding stars to show that theuniverse is expanding at an accelerating rate. They assumed that these supernovae are spreading apart faster as the universe ages. Physicists also assumed that a kind of anti-gravitational force must be driving the galaxies apart, and started to call this unidentified force "dark energy".
However, to this day no one actually knows what dark energy is, or where it comes from. Professor Senovilla, and colleagues have proposed a mind-bending alternative. They propose that there is no such thing as dark energy at all, and we’re looking at things backwards.
Senovilla proposes that we have been fooled into thinking the expansion of the universe is accelerating, when in reality, time itself is slowing down. At an everyday level, the change would not be perceptible. However, it would be obvious from cosmic scale measurements tracking the course of the universe over billions of years. The change would be infinitesimally slow from a human perspective, but in terms of the vast perspective of cosmology, the study of ancient light from suns that shone billions of years ago, it could easily be measured.
The team's proposal, published in the journal Physical Review D, dismisses dark energy as fiction. Instead, Senovilla says, the appearance of acceleration is caused by time itself gradually slowing down, like a clock with a run-down battery.* “We do not say that the expansion of the universe itself is an illusion," he explains. "What we say it may be an illusion is the acceleration of this expansion - that is, the possibility that the expansion is, and has been, increasing its rate."
If time gradually slows "but we naively kept using our equations to derive the changes of the expansion with respect of 'a standard flow of time', then the simple models that we have constructed in our paper show that an "effective accelerated rate of the expansion" takes place."*Currently, astronomers are able to discern the expansion speed of the universe using the so-called "red shift" technique. This technique relies on the understanding that stars moving away appear redder in color than ones moving towards us. Scientists look for supernovae of certain types that provide a sort of benchmark.
However, the accuracy of these measurements depends on time remaining invariable throughout the universe. If time is slowing down, according to this new theory, our solitary time dimension is slowly turning into a new space dimension. Therefore the far-distant, ancient stars seen by cosmologists would from our perspective, look as though they were accelerating.
"Our calculations show that we would think that the expansion of the universe is accelerating," says Prof Senovilla. The theory bases it’s idea on one particular variant of superstring theory, in which our universe is confined to the surface of a membrane, or brane, floating in a higher-dimensional space, known as the "bulk". In billions of years, time would cease to be time altogether.
"Then everything will be frozen, like a snapshot of one instant, forever," Senovilla told New Scientist magazine. "Our planet will be long gone by then."
Though radical and in many way unprecedented, these ideas are not without support. Gary Gibbons, a cosmologist at Cambridge University, says the concept has merit. "We believe that time emerged during the Big Bang, and if time can emerge, it can also disappear - that's just the reverse effect."