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Dark energy, doomsday and you

Posted on July 23, 2012 - 13:04 by TG Daily Staff

Dark energy is believed to make up approximately 70 percent of the current content of the universe.

Several possible scenarios involving dark energy have been postulated by scientists, including one that predicts the universe will end in a so-called big rip.



Of course, predicting the ultimate fate of a truly enigmatic universe is somewhat difficult when there is an absence of consensus on what dark energy actually is.

Nevertheless, a team of Chinese researchers attempted to tackle the controversial topic in a paper titled "Dark Energy and Fate of the Universe" which was recently published in the Sci China-Phys Mech Astron journal. 



"In the absence of a consensus on what dark energy is, a phenomenological description of the equation-of-state parameter w - the ratio of pressure and density of dark energy - provides an important means for investigating dark energy dynamics," the authors explain. 



"Properties of dark energy will decide the ultimate fate of the Universe. In particular, if w<-1 at some time in the future, dark energy density will grow to infinity in finite time, and its gravitational repulsion will tear apart all the objects in the Universe."



As noted above, the "big rip" (or "cosmic doomsday") scenario is the major focus of the paper. So, if a doomsday scenario exists, how far are we from it?



To determine the fate of the universe, the researchers adopted a divergence-free parameterization dubbed "Ma-Zhang" (MZ). 

After computing a series of complex equations, the team determined that in the worst case scenario, the Milky Way will likely be torn apart before the big rip occurs.

The researchers also calculated that two months before doomsday, the Earth will be "ripped" from the Sun, while the moon will be ripped from the Earth five days before the end. And, in true Hitchhiker's fashion, the earth will explode 16 minutes before the universe ceases to exist.

"However, from what we already know of the dynamical properties of dark energy, one thing is all very clear, we still have a very long future ahead," the researchers added.

Whew.

You can read more about dark matter here, on NASA's official homepage. - sumber