| MadSci Network: Physics |
Dear Mary!
I suppose that what you are referring to is the recent experimental
confirmation of the Casimir Effect with amazing accuracy. The
`original' Casimir effect is the appearance of a tiny force between two
parallel, conducting plates which are a small distance apart.
What has this got to do with creation of matter or energy out of the
vacuum? In order to understand this you have to realize that today's
physicists' view of the `vacuum' is different from the usual meaning
of the word. Due to the laws of quantum mechanics, it is possible for
elementary particles to be created `from nothing', interact for a short period
of time and then annihilate into the void. This happens everywhere,
all the time. The vacuum is teeming with activity on a sub-microscopic
scale! Now, you might have heard that particles can behave like waves
under certain circumstances, and that's where the Casimir effect emerges:
Placing a `chunk' of vacuum between a pair of parallel conducting plates
subjects the vacuum to boundary conditions. As a consequence,
waves with a wavelength which is larger than twice the distance between
the plates cannot exist there. So, the activity of the vacuum I described
above is limited between the plates. It is limited insofar as
very low-energy particles (those with large wavelengths) are excluded.
On the other hand, they are not excluded outside the plates.
Hence it follows that there is, in a sense, more `teeming' outside the
plates than inside, and this leads to the observed attractive force.
The experimental confirmation to about 5% accuracy was recently done by Steve Lamoreaux at the U of Washington. To get more insight into theory and experiment, take a look at this bibliography of the Casimir Effect.
Hope that helps,
Georg.