Vacuum energy: something for nothing?
01 October 2005
David Shiga
New Scientist Magazine issue 2519

Is empty space really fizzing with energy? The answer may determine the
fate of the universe IT doesn't sound like the kind of thing that would affect our cosmic
fate. Put two metal sheets close together - very close - in a vacuum and
you'll find they attract each other with a small but measurable force.

Sounds more like a simple curiosity, doesn't it? Except physicists
believe that the energy source that is pushing those plates together may also
be pulling the universe apart. The traditional explanation for the
"Casimir effect" (it is named after the Dutchman who predicted its existence
more than half a century ago) is that empty space is in fact crackling with
"zero-point energy", a phenomenon arising from quantum theory. It is
this energy that pushes the metal plates together.

The same zero-point energy, backed up by evidence from the Casimir
effect, is also a leading candidate to explain the mysterious dark energy that
seems to be expanding the universe...

(The complete article is 2314 words long.
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