ZPEnergy.com - A Cosmic Coincidence Resurrects the Cyclical Universe

Over the past five years or so, scientists have finally converged on a model of the universe that explains (or at least permits) all of its characteristics. The new cosmological model has one very surprising feature, however, which is supported by several robust and unrelated observations. In addition to matter and radiation, it seems that the vacuum of space is filled with a mysterious ‘dark energy’ that pushes the universe apart. While the dark energy helps us explain a great many things, it also resurrects an old problem once thought buried—the idea that our universe is the product of a highly unlikely cosmic coincidence.

...Once again, cosmologists find themselves debating the initial conditions of the universe. One common explanation, which has been used for decades to solve fine-tuning problems, is called the anthropic principle. In essence, this is the statement that we must live in a universe that can support life because we are here to observe it. This statement isn’t very satisfying, however, since it doesn’t offer any new insight into the nature of the universe...
...

But what if the universe is much older than it appears? Professors Paul Steinhardt (Princeton University) and Neil Turok (Cambridge University) have come up with a novel solution that gives the cosmological constant time to decay to its required value. Resurrecting a ghost of the cyclical universe, they propose that our universe is one of two embedded in the eleven-dimensional space of string theory.

The two universes are linked with a spring-like attraction, and so pass through each other (moving along one of the higher dimensions) periodically. Every time they interact, enormous energies are released and both universes fill with hot plasma—a new Big Bang. There is no Big Crunch, as both universes are constantly expanding. A trillion years or so after one Big Bang, when the universe is practically empty, another Big Bang occurs and the stars and galaxies can form once more.

The underlying cosmological constant, however, is unaffected by this process and has all the time it needs to decay to a small value. Eventually stars and galaxies will have time to form, and the same will be true of every subsequent cycle. In this modern version of the old cyclical model, the coincidence is resolved because only a few cycles are required for the cosmological constant to decay. The number of star-producing cycles following the decay, however, is practically infinite.

Either way, it is clear that our perspective has changed. A single universe is no longer satisfying, given the most unlikely nature of our own. To explain our existence, it seems we must imagine others.

Source: http://www.physorg.com/news68731082.html

SCIENTISTS PREDICT HOW TO DETECT A FOURTH DIMENSION OF SPACE, May 25

Scientists at Duke and Rutgers universities have developed a mathematical framework they say will enable astronomers to test a new five-dimensional theory of gravity that competes with Einstein's General Theory of Relativity.

The framework Keeton and Petters developed predicts certain cosmological effects that, if observed, should help scientists validate the braneworld theory. The observations, they said, should be possible with satellites scheduled to launch in the next few years.

If the braneworld theory proves to be true, "this would upset the applecart," Petters said. "It would confirm that there is a fourth dimension to space, which would create a philosophical shift in our understanding of the natural world."

Source: http://www.physorg.com/news67773542.html