| Dreaming Of Pandora |
07-11-2010 11:37 AM |
Time May Be Disappearing From The Universe.
A new possible explantion for dark energy has resulted in a new theory of how the Universe might end.
The article is very vague so I'll explain what's going on underneath it. :)
Quote:
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 the universe 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".
The idea that time itself could cease to be in billions of years - and everything will grind to a halt - has been proposed by Professor José Senovilla, Marc Mars and Raül Vera of the University of the Basque Country, Bilbao, and University of Salamanca, Spain. The corollary to this radical end to time itself is an alternative explanation for "dark energy" - the mysterious antigravitational force that has been suggested to explain a cosmic phenomenon that has baffled scientists.
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, say 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."
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Okay here's what the article says but in a lot clearer way.
Dark energy is the name of what cosmologists think is causing the increasing rate of spacetime expansion in our Universe. An anti-gravity force so to speak. But now, physicists are saying that time could be the cause of this.
Try to imagine a tube; the lenght of the tube being time and the width of it being space. Before dark energy is was thought that the length of the "tube" and the width grew at a standard, equal rate. After dark energy we see that the width (space) of the tube is growing faster than the lenght (time) of it. This means that there is more space created than time.
Since time and space are one thing, that means that, for some reason, time is being lost or is disappearing from the Universe. Time (the "lenght") is in fact getting shorter as space (the "width") is getting wider.
This can only mean that the end of the Universe will be that time gets so short that the Universe will end as an instant, a "photo" of the Universe. |
