Posted on 07/16/2007 12:26:58 PM PDT by SunkenCiv
The mysterious cosmic presence called dark energy, which is accelerating the expansion of the universe, might be lurking in hidden dimensions of space. The idea would explain how these dimensions remain stable - a big problem for the unified scheme of physics called string theory... quantum vibrations in the vacuum of space (called vacuum energy or the cosmological constant) that could produce repulsive gravity... should either possess a ridiculously high energy density - 122 orders of magnitude larger than are observed - or cancel out to exactly zero. To make them almost-but-not-quite cancel, in agreement with astronomical observations, means fudging the quantum field equations. Unless, that is, the quantum vibrations are stuck in a small space... Even though the vibration is imprisoned in these other dimensions, it can extend its gravitational influence into our space. Its gravity is also repulsive in our space, just like the "ordinary" cosmological constant, so it would cause cosmic acceleration. To get the same amount of acceleration seen by astronomers, Greene and Levin calculate that the extra dimensions should have a scale of about 0.01 millimetre. Dark energy would be hiding less than a hair's breadth away... Eric Adelberger and his team at the University of Washington in Seattle, US, have run a series of experiments using a twisting pendulum to measure the short-range strength of gravity, and they have already ruled out extra dimensions larger than a 0.1 millimetre. They are planning a new experiment to probe shorter distances still.
(Excerpt) Read more at space.newscientist.com ...
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Physicists find way to ‘see’ extra dimensions
University of Wisconsin-Madison | February 2, 2007 | Jill Sakai
Posted on 02/03/2007 4:23:00 PM EST by SunkenCiv
http://www.freerepublic.com/focus/chat/1778729/posts
So is the article stating that dark energy could produce anti-gravity?
:’) Hey, it should be doing something instead of just sitting there on the chalk board. ;’)
I dunno about dark energy, but I’ve heard that it’s pretty dark inside of algore’s brain...
But not in New Orleans!
So is the article stating that dark energy could produce anti-gravity?Good question. Dark energy is being "blamed" for the increase in the expansion of the universe, which is a kind of anti-gravity. But does that mean you can bottle it up and fuel a flying carpet with it? I don't know.
Speaking of energy, where is the thread about the oil industry report that says they won’t be able to keep up with demand in the couple decades ahead?
Don’t knock Algor, its a very cost efective FEA program; unless you mean... nevermind.
“To make them almost-but-not-quite cancel, in agreement with astronomical observations, means fudging the quantum field equations.”
Well, that’s one way to do it.
I prefer —
1. Create a hypothesis.
2. Devise a means to test the hypothesis.
3. Perform the test.
4. Collect data.
5. Alter the data to fit the hypothesis.
:’D
Ah, yes, the Global Warming Scientist’s “Scientific Method for Dummies”.
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