Why does gravity not explain the Casimir Effect?

[Nick Bratcamp]

Please explain how the gravitational effects are accounted for in the Casimir Effect? At a basic level, I want to understand why the quantum vacuum fluctuations in the electromagnetic field are the cause of the attractive force rather than gravity.

 

[Demystifier]

When the distance between plates is much smaller than the size of the plates, the gravitational force does not depend much on the distance. On the other hand, experiments show that the force rapidly decreases with the distance, which can be correctly explained by quantum fluctuations.

There is some dispute among experts whether these quantum fluctuations should be viewed as vacuum fluctuations or matter fluctuations (van der Waals force).