Study validates general relativity on cosmic scale, existence of dark matter

An analysis of more than 70,000 galaxies by University of California, Berkeley, University of Zurich and Princeton University physicists demonstrates that the universe - at least up to a distance of 3.5 billion light years from Earth - plays by the rules set out 95 years ago by Albert Einstein in his General Theory of Relativity.

By calculating the clustering of these galaxies, which stretch nearly one-third of the way to the edge of the universe, and analyzing their velocities and distortion from intervening material, the researchers have shown that Einstein's theory explains the nearby universe better than alternative theories of gravity.

One major implication of the new study is that the existence of dark matter is the most likely explanation for the observation that galaxies and galaxy clusters move as if under the influence of some unseen mass, in addition to the stars astronomers observe.

"The nice thing about going to the cosmological scale is that we can test any full, alternative theory of gravity, because it should predict the things we observe," said co-author Uros Seljak, a professor of physics and of astronomy at UC Berkeley, a faculty scientist at Lawrence Berkeley National Laboratory, and a professor of physics at the Institute of Theoretical Physics at the University of Zurich. "Those alternative theories that do not require dark matter fail these tests."

www.physorg.com...

We keep going in this "dark stuff" direction. It seems like everytime we have a new candidate for dark matter we find that even combinnig these various possibilities that we still do not have enough (to account for the apparent needed mass and mass density of the universe).

So even with more validation from relativity we seem to be not one step closer to solving the dark matter anomoly. Still it's interesting to see that other popular theories did not cut the mustard.

I imagine there will be more complete theories coming out now that electrogravitics are starting to truely be understood.
I reckon you read this already:

Relativity smashed...somewhat

Will be interesting to see what, if any effect this has on the dark matter theory.

There still seems to be a lot of unanswered questions, even as close to home as our own sun. I believe the sun exibits some anomalies that relativity can't explain. That's not to say that Einstein was wrong, not at all but I do believe they are missing something. Possibly Plasma Cosmology could help and be integrated into Einstein's and Newton's laws instead of being toltally ignored.

I'm still completely against this whole "dark matter" idea...

I keep coming back to the complete lack of understanding we seem to have of gravity.

It's always said that light speed is the fastest speed in the Universe, but then that all seems out the window when trying to assess the speed of gravity. If I recall correctly, like for example when calculating when and where you'd see a celestial object you have to basically assume the speed of gravity as infinite or instantaneous, to get the correct prediction...

So, hmm...maybe it is instantaneous?

Until we understand exactly what gravity is, and how it behaves, my feeling is that we're really just creating more sacred cows that stagnate advancement....

The theory of relativity has been validate over and over for many years since Einstein published it, so what is the big news here? I read that article and it had more to do with light curving through vast distances in space due to gravity and while there was mention of dark matter, I do not think the experiment offered proof of such.

Originally posted by Gazrok
I'm still completely against this whole "dark matter" idea...

Back 60 years ago you would be "completely against" neutrinos. Some people just are like that.

I keep coming back to the complete lack of understanding we seem to have of gravity.

I take it that you took classes in this subject, right?

If I recall correctly, like for example when calculating when and where you'd see a celestial object you have to basically assume the speed of gravity as infinite or instantaneous, to get the correct prediction...

No you don't recall it correctly.

reply to post by buddhasystem

Back 60 years ago you would be "completely against" neutrinos. Some people just are like that.

No, I'm against it because it's so widely accepted as gospel without much evidence.

I take it that you took classes in this subject, right?

You are correct sir. Perhaps not to the degree you have had perhaps, (judging by some of your posts), but enough to want to see more evidence for it, before taking it (dark matter) almost as fact.

No you don't recall it correctly.

Really?
metaresearch.org...

Einstein’s special relativity (SR), an experimentally well-established theory, proved that nothing could propagate in forward time at a speed greater than that of light in a vacuum. Indeed, as astronomers we were taught to calculate orbits using instantaneous forces; then extract the position of some body along its orbit at a time of interest, and calculate where that position would appear as seen from Earth by allowing for the finite propagation speed of light from there to here. It seemed incongruous to allow for the finite speed of light from the body to the Earth, but to take the effect of Earth’s gravity on that same body as propagating from here to there instantaneously. Yet that was the required procedure to get the correct answers.

Van Flandern, T. (1998), The speed of gravity: What the experiments say. Physics Letters, A250:1-11. Retrieved March 12, 2010, from metaresearch.org...

(granted, its an older paper, but I haven't seen anything refute that you have to allow for it to get the right predictions of location)...

If you have some references to show a measured speed of gravity, I would be most excited to see them. (and that's an honest statement)... I'm aware of the 2003 experiment that claimed this, and that it was (statistically) equal to the speed of light, but just as many physicists disagree with that assessment.



[edit on 12-3-2010 by Gazrok]