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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 a 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.
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NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Based on Astronomy Picture
Of the Day
Publications with keywords: cosmology
Publications with words: cosmology
See also: