archived as http://www.stealthskater.com/Documents/BigBang_2.
doc [pdf]
more of Cosmology at http://www.stealthskater.com/Science.htm
note: because important websites are frequently "here today but gone tomorrow", the following was
archived from http://www.space.com/scienceastronomy/astronomy/new_universe_020425.html
on May 1, 2002. This is NOT an attempt to divert readers from the aforementioned website.
Indeed, the reader should only read this back-up copy if the updated original cannot be found at
the original author's site.
In New Theory of Universe, Time Never Ends
By Robert Roy Britt
Senior Science Writer
posted: 02:00 pm ET
25 April 2002
[StealthSkater note: this research was built upon the Ekpyrotic model => doc pdf
URL-doc URLpdf
Paul Steinhardt's universe is a lot like the workaday world of many people -- a cycle of early vigor,
spent energy, exhausted return, and new beginnings. However, in Steinhardt's universe, there is
absolutely no end to the cycle.
The Princeton physicist and his colleague Neil Turok of Cambridge University have developed a
whole new theory for how the Universe came to be. Their proposal seeks to explain recently uncovered
flaws in the scientifically accepted model for the origin and evolution of all known things. It describes a
series of "Big Bangs" and equally significant crunches that form a never-ending cycle of rejuvenation
and destruction.
In this universe -- our Universe -- time never ends.
The current leading theory for the Universe holds that it emerged from a single Big Bang sometime
around 12-to-15 billion years ago, undergoing an early and rapid period of inflation. That much remains
widely accepted.
"However, the standard model has some cracks," Steinhardt and Turok write in a paper published
today in the online version of the journal Science.
Astronomers have in recent years learned that the Universe is not just expanding, but it is doing so at
an ever-increasing pace. This can't be explained given the known matter and energy that exists. To
account for the acceleration, theorists have conjured a product they call 'dark energy' which supposedly
repels things rather than attracting as gravity does.
No one has seen this 'dark energy', and scientists don't even know what it is. But they say it's all
around us.
More important, it shouldn't be there.
1
"The recent discoveries of cosmic acceleration and gravitationally self-repulsive 'dark energy' were
not predicted and have no particular role in the standard model," Steinhardt and Turok argue.
"Furthermore, the standard model does not explain the beginning of time', the initial conditions of the
Universe, or what will happen in the long-term future."
So to patch some of the theoretical cracks, Steinhardt and Turok envision a Universe based on
perpetual expansion and contraction.
Here's how it works (and keep in mind we're jumping into the middle of the explanation): a 'Big
Bang' sends everything outward. Matter and radiation develop. Dark energy drives an expansion -- as is
presently underway -- that lasts trillions of years. Finally, the matter, radiation, and even black holes are
"diluted away", leaving the Universe smooth, empty, and flat.
Then everything contracts in a so-called 'Big Crunch' and a fresh cycle begins.
"In this picture, space and time exist forever," Steinhardt says. "The Big Bang is not the beginning
of time. Rather, it is a bridge to a pre-existing contracting era."
Curiously, the cyclic Universe -- as it is called -- puts the origin of some present-day structures and
events prior to the Big Bang.
While existing theory states that galaxies and large clusters of galaxies developed from lumps and
filaments that formed in the otherwise smooth fabric of space and time shortly after the Big Bang,
Steinhardt thinks the seeds of galaxy formation were created by instabilities that arose during the last
contraction before the 'crunch' that led to "our" 'bang'.
The new model "turns the conventional picture topsy-turvy," he says.
The cyclic universe has roots in even more complex thoughts like so-called superstring theory
which suggests there are as many as 10 spatial dimensions -- not just the normal three that we know of.
The seemingly inexplicable physics of a 'Big Crunch' and a 'Big Bang' might be explained with the aid
of these extra dimensions -- which are otherwise invisible to us, several theorists believe.
In fact, Steinhardt, Turok, and others proposed last year that our Universe might have sprung from
the collapse of an extra dimension. It was an idea they called the Ekpyrotic Universe. The cyclic
Universe builds on this former work but, Steinhardt says, does a better job explaining observations of
our present Universe.
Other theorists are not quick to give up their standard model, so the concept of a "cyclic Universe"
faces an uphill battle for prominence. Even Steinhardt acknowledges that the prospect of unseating a
well established cosmological theory "would seem extremely dim".
Meanwhile, the new concept is not free of cracks, either. Even the cyclic Universe does not address
when the cycles began, so "the problem of explaining the beginning of time remains," the researchers
say.
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