Hi,

Even though it is called 'vacuum energy'... do we know or do we have some theory on... whether the activities of virtual particle pairs is the same whether in the relative vacuum of space or... with in ther Earth's atmosphere (where tests confirmed it) or... say inside a rock?

Rusty

Whether inside a rock or isolated outer space, particle interactions pretty much look the same in all cases, they're described by the same equations. Naturally if you're inside a rock, you'll see all kinds of magnetic and electric fields at the microscopic level. These interactions are ultimately catalyzed by virtual photons (and other particles) popping in and out of the vacuum, so the presence of atoms clearly has an influence on the properties of the vacuum nearby. On the other hand if you're asking whether the zero point energy is affected, I wouldn't think so, because the zero point vacuum energy is only defined in cases where you have no real particles in the area.