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Astronomy Picture of the Day
NASA ^
| 01/03/10
| Umar Mohideen
Posted on 01/03/2010 5:52:54 AM PST by sig226
A Force from Empty Space: The Casimir Effect
Credit & Copyright: Umar Mohideen (U. California at Riverside)
Explanation: This tiny ball provides evidence that the universe will expand forever. Measuring slightly over one tenth of a millimeter, the ball moves toward a smooth plate in response to energy fluctuations in the vacuum of empty space. The attraction is known as the Casimir Effect, named for its discoverer, who, 50 years ago, was trying to understand why fluids like mayonnaise move so slowly. Today, evidence is accumulating that most of the energy density in the universe is in an unknown form dubbed dark energy. The form and genesis of dark energy is almost completely unknown, but postulated as related to vacuum fluctuations similar to the Casimir Effect but generated somehow by space itself. This vast and mysterious dark energy appears to gravitationally repel all matter and hence will likely cause the universe to expand forever. Understanding vacuum fluctuations is on the forefront of research not only to better understand our universe but also for stopping micro-mechanical machine parts from sticking together.
TOPICS: Astronomy Picture of the Day
KEYWORDS: apod; casimir; freeenergy; vacuumenergy; zeropointenergy
The Casimir effect, for those who don't understand it, is an implication of quantum theory. Vitrual quantum particles fluctuate in the universe, appearing and disappearing at random. If two plates are placed close together (measured in microns) the wavelengths of some virtual photons are too long to exist between the two plates. These virtual photons are excluded from the space. They are not excluded from the space outside the plates. That means that there are more of them, therefore more force, outside the plates than there are between the plates. The plates will be pushed together because of the unblanced forces.
The effect has been measured.
1
posted on
01/03/2010 5:52:56 AM PST
by
sig226
To: null and void; fnord; Number57; KevinDavis; rdb3; MNJohnnie; RightWhale; proudofthesouth; ...
2
posted on
01/03/2010 5:53:29 AM PST
by
sig226
(Bring back Jimmy Carter!)
To: sig226
I’ll take your word for it.
3
posted on
01/03/2010 5:56:09 AM PST
by
cripplecreek
(Seniors, the new shovel ready project under socialized medicine.)
To: sig226
Uh. OK.
Actually, I DO love this stuff!
I like the REALLY BIG stuff like Galactic Clusters and Star Nurseries.
I like the really Little stuff like quarks and neutrinos (Mexican neutrons? LOL)
Thanks for sharing, Sig226.
4
posted on
01/03/2010 6:36:49 AM PST
by
left that other site
(Your Mi'KMaq Paddy Whacky Bass Playing Biker Buddy)
To: left that other site
Casimir Neutrino?
5
posted on
01/03/2010 6:38:07 AM PST
by
left that other site
(Your Mi'KMaq Paddy Whacky Bass Playing Biker Buddy)
To: sig226
your explanation is much clearer than NASA’s verbage.
thanks for posting this thread all the time ...
6
posted on
01/03/2010 7:07:24 AM PST
by
fnord
(Beauty often seduces us on the road to truth.)
To: fnord
I was going to say something but after I saw your screen name I forgot...
7
posted on
01/03/2010 7:26:42 AM PST
by
null and void
(We are now in day 346 of our national holiday from reality. - 0bama really isn't one of US.)
To: sig226
So what is a vitrual quantum particle? I hope it is not anything like a vitriol particle!
8
posted on
01/03/2010 10:49:21 AM PST
by
NonLinear
(.45 ACP - Because having to shoot someone twice is just silly.)
To: sig226
>"there are more of them, therefore more force, outside the plates than there are between the plates. The plates will be pushed together because of the unblanced forces"Wouldn't that cause the opposite of expansion?
9
posted on
01/03/2010 10:51:25 AM PST
by
rawcatslyentist
(Jeremiah 50:31 Behold, I am against you," O " you most proud, said the said the Lord GOD of hosts)
To: rawcatslyentist
If you meant the force betweenthe plates, then no. There is less force between the plates than outside of them because some virtual particles can’t exist in the small space between the two plates.
If you’re not sure how this means that the universe must expand forever, neither am I. I think they’re extrapolating the effect of unaccounted forms of energy to explain the problems observed with galactic rotations.
10
posted on
01/04/2010 5:59:39 AM PST
by
sig226
(Bring back Jimmy Carter!)
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