Another attempt to understand the Universe

Kulapavana · November 10, 2003

The Dallas Morning News

Published: November 9, 2003 Author: TOM SIEGFRIED

KNOXVILLE, Tenn. – The Elegant Universe is an excellent title for a book, and a PBS special.

Unfortunately, it's not all that accurate. Just as real life is never as neat and clean as it is in novels and movies, the real universe defies the simple pictures that popularizations paint of it. In fact, the universe is a mess.

"This is a preposterous universe," University of Chicago physicist Sean Carroll told a group of science writers last month at a seminar in Knoxville. "Most of us could have done a better job of designing a universe if we'd been given that as a homework assignment."

One major sign of the universe's messiness is its makeup. The list of its ingredients turns out to be a recipe for disaster. Only about 3 percent of the total mass-energy mixture is in the form of ordinary matter, the sort that planets and people and stars are made of. About 26 percent is some exotic sort of matter, a species not yet identified (and almost surely a species that has not yet been discovered). And the 70 percent remaining is even more mysterious – it's an unknown form of energy that took command of the universe a few billion years ago, forcing space to expand at an accelerating rate. Hence the disaster – the universe seems to be blowing itself up.

The repulsive ingredient is usually called "dark energy," because it doesn't shine like light. But it may be a form of energy that already has a name. Einstein suggested the existence of an energy inherent in space that came to be called the "cosmological constant," since it occupied space throughout the cosmos, at a constant strength everywhere.

But let's face it, "cosmological constant" is a geeky name and it takes too much ink to explain it every time you use it.

Dr. Carroll prefers a more descriptive term, derived from the dark energy's properties. Since it is presumably the same strength everywhere, it's like a very smooth fluid. And since it exerts a repulsive effect on space – essentially trying to stretch space out – this energy generates a sort of cosmic tension throughout the universe. So Dr. Carroll is pushing the label "smooth tension" in place of dark energy.

Whether that name catches on or not, the idea of a universe dominated by a dark smooth cosmic repulsive tension remains disconcerting to many cosmologists. For one thing, it makes the future of the universe almost impossible to predict. At the moment, the universe is expanding at an accelerating rate, suggesting that it will keep on expanding forever and ever. But perhaps the smooth tension is only smooth in space and not in time – that is, it might be the same everywhere now, but could change strength in the future. If its strength diminishes, maybe the universe will stop expanding and collapse someday.

Or perhaps there's yet another ingredient in the cosmic recipe, a tiny hidden anti-tension that can't outcompete the repulsion now, but will someday grow strong enough to counteract it.

Furthermore, Dr. Carroll pointed out, there's a small chance (maybe about 2 percent) that these efforts are misguided, and that the recipe for the universe has been miswritten.

"Maybe there is no such thing as dark matter, and maybe there's no such thing as dark energy," he said at the seminar, organized by the Council for the Advancement of Science Writing. "We only detected them through their gravitational influence, and maybe we don't understand gravity as well as we think we do."

So far, though, efforts to change Einstein's theory of gravity to explain the dark items in the universal recipe raise other problems.

"It's just very hard to out-Einstein Einstein," Dr. Carroll said. "Probably there really is dark matter and dark energy out there."

In any event, most physicists hope to construct theories that would specify the universe's ingredients more precisely. And theorists have at least one excellent if rather elaborate idea. If you allot them enough extra dimensions of space and time beyond the usual four, the theorists can produce some very elegant equations that might someday make sense of the universe.

Alas, the theorists will need some help from other physicists and astronomers trying to find out through experiment and observation what the universe contains. Dozens of efforts are under way to capture an example of that exotic matter that makes up 26 percent of the universe, or to learn more about the properties of the dark energy, or to measure the dim cool light left over from the big bang for further clues about the universe's properties. Other projects hope to produce samples of the exotic matter in a particle accelerator and even to make measurements to prove that those extra dimensions of space really exist.

Over the next decade or two, then, fans of the cosmos can expect some intriguing headlines announcing progress in showing just how preposterous the universe really is.

"We really live in the most exciting time in the history of cosmology," said Dr. Carroll. "There's no reason to believe that the fun part is over yet. The fun is actually only just beginning."

E-mail tsiegfried@dallasnews.com

Kulapavana · November 10, 2003

"Einstein suggested the existence of an energy inherent in space that came to be called the "cosmological constant," since it occupied space throughout the cosmos, at a constant strength everywhere"

They are right about this one - everything rests on Krishna, like pearls on a thread...

November 12, 2003

uhh,no doc,sorry.

Einstein called the cosmological constant the biggest

mistake of his life.

in fact it is a theory to try to explain away

the inconsistincies in other theories,

most often the big bang theory.

http://www.physicsmyths.org.uk/

this site has a lot of interesting stuff,

here's a taste

Dark Matter: As the observed rotation speed of gas in the outer regions of most galaxies is not compatible with the gravitational force related to the visible galactic masses, it has been concluded that these galaxies are either surrounded by a massive invisible halo of 'dark matter', or that Newton's law of gravitation has to be modified. However, these theories completely neglect electromagnetic forces on the galactic plasma and their indirect coupling to the neutral gas dynamics by means of recombination (more).

General Relativity: In his theory of Special Relativity, Einstein attempted to establish space and time as physical objects in their own right, making them scaleable quantities in order to conform with the observed invariance of c in reference frames moving uniformly relative to each other. In his General Relativity, he extended this concept to forces and the related accelerated coordinate systems (in particular with regard to gravitation). With his interpretation, the motion of a mass is determined by the curvature of space-time which in turn is caused by the presence of other masses. This view is inconsistent in several respects: a) it claims that a physical action can result from a 'subject' (i.e. space-time) which has no physical reality but exists only as an idealized, mathematical concept; b) although physical forces are frequently described by gradients of some potential function, this is in principle not acceptable as the fundamental form for the interaction as it implies a non-local nature (a gradient can not be defined through a point); c) there is no reason why a motion due to gravitational forces should be described by a different concept than those for electrostatic interaction for instance; however for the latter the force does not depend on the mass (whereas the resultant acceleration does), therewith invalidating the concept of space-time curvature as an objective and unique quantity for describing the motion of objects in force fields; d) Einstein claims that the alleged space-time curvature around massive objects will affect the path of light rays as well. This is an unallowed generalization as the concept was derived to describe the gravitational interaction, but electromagnetic waves are immaterial and massless physical objects. Effects that apparently confirm this prediction of General Relativity could well be explained by other mechanisms

http://www.electric-cosmos.org/darkmatter.htm

for more on the dark matter/dark energy theory