On 2/11/2013 1:17 PM, Peter Fairbrother wrote:
On 11/02/13 13:00, David Spain wrote:

OTOH if an experimentalist can prove non-zero ground-state vacuum
energy, there would no doubt be a Nobel Prize in Physics lurking there
for such a clever scientist.... Need a goal?

Hasn't that been done? Casimir effect? It is standard model.


-- Peter Fairbrother


I don't think they are the same. One interpretation of the Casimir
effect is that it measures "resonances" or fluctuations in the vacuum
energy between closely spaced parallel plates and can actually measure
an attractive or repulsive force between them. But there are other
interpretations that don't invoke ZPE to explain the effect. Therefore
it does not establish a definitive existence of vacuum energy, nor does
it establish a value for the ground state vacuum energy.

A non-zero ground state vacuum energy would imply a form of
'anti-gravity' the pervades the universe and drives its expansion. At
least that is my understanding of the situation. And although the former
has been proved by a Nobel Prize winning experiment the latter still
awaits its Nobel (my bias is showing)...

The Casimir effect, if it truly is observing ZPE, is pretty astounding.
Almost (but not quite IMHO) as weird as the locally intuitive 2nd Law of
Thermodynamics is when considered at the cosmological scale....

Dave