How much negative energy is that space between two non-conducting plates?

[Negeng]

The negative pressure generated in the Cashmeir effect suggest that negative energy can exist in small spaces between non-conducting plates. How much negative energy exist in a given amount of space as measured in units that refer to energy (as opposed to units of force created by the Cashmeir effect)?

 

[SpectraCat]

The negative pressure generated in the Cashmeir effect suggest that negative energy can exist in small spaces between non-conducting plates. How much negative energy exist in a given amount of space as measured in units that refer to energy (as opposed to units of force created by the Cashmeir effect)?

As I understand it, there is no consensus on the proper interpretation of the Casimir effect. I do not know that it has been unambiguously shown to be due to the supposed restriction on the wavelengths of virtual particles that can pop into existence between the plates. There is an alternative interpretation which I believe incorporates relativistic effects for the van der Waals force which become significant at the very short distances required to measure the Casimir effect. There are other threads on PF which deal with this topic.

https://www.physicsforums.com/showthread.php?t=372417
https://www.physicsforums.com/showthread.php?t=396300