Did dark energy give us our cosmos?

17 January 2009 by Jessica Griggs

OUR universe may have arisen from seeds preserved in a universe that existed before the big bang - all thanks to dark energy.

One of the models put forward to explain how the universe began proposes that it is just the latest phase in a never-ending cycle. Proposed in 2002 by Paul Steinhardt of Princeton University and Neil Turok from the University of Cambridge, the model argues that our universe exists on a 3D region called a "brane" separated from similar branes by a fourth spatial dimension. Under the right conditions, these branes collide, triggering a big-bang-like event. After the collision, the branes bounce apart, before another collision occurs many billions of years later.

This model initially struggled to explain the ripples in the temperature and density of the universe that can be seen in the cosmic microwave background radiation left over from the big bang. The only way to make calculations based on the cyclic model produce the observed pattern of ripples is to add extra dimensions, as predicted by string theory, on top of the four spatial dimensions that the initial scenario envisaged.

Unfortunately, adding extra dimensions throws up another problem. As two branes approach, the additional dimensions must shrink or grow in sync with the dimension that separates the branes. Otherwise, large areas of the brane become warped, so that most of it ends up as black holes and only a tiny proportion as ordinary, habitable space. After several cycles, this space shrinks to nothing, so the process is unlikely to have led to our universe.


Now calculations by Steinhardt and Jean-Luc Lehners, also at Princeton, show that when dark energy - the stuff that appears to be causing the expansion of the universe to accelerate - is brought into the picture, the cycling can be sustainable, so long as dark energy dominates for around 600 billion years.

more:
http://www.newscientist.com/article/mg20126914.100-did-dark-energy-give-us-our-cosmos.html?DCMP=OTC-rss&nsref=space

Thanks for posting this fantastic article.

to me anyway.

and the universe is effectively eternal with periods of "stuff" and no "stuff" then couldn't a sufficiently advanced civilization theoretically exist from one period of "stuff" to another?

If I hadn't solved the anti-gravitational aspect of the Hubble Constant in a model before the rest of the scientific community, I might not have stumbled on to what could be a ridiculously simple explanation for dark matter.

Frankly, anti-gravity and dark matter are based on the same function of the Hubble Constant.

Anyone interested?

(Seriously, I hate spending loads of time on this stuff when no-one is curious... even if I can just cut and paste a whole bunch of it)

but it sure as hell gave us the Bush/Cheney administration!:evilgrin:

Bush came from the region of space with no brane.