Understanding Physics: The Exchange of Virtual Photons

[wdlang]

It seems to me that the physics is the same

they are all due to the exchange of virtual photons between two particles

 

[Sojourner01]

I'm grappling with the same problem myself. From what I can gather, the casimir force is due to the interaction of the vacuum itself with its boundaries, and the van der waals force is a property of the materials that make up the boundary. You have to delve deeper into it to see the difference - and there are those who think that the casimir force can be adequately explained by van der waals-type interactions between the atoms in the 'plates'.