Is the Casimir Effect the Same for Insulators as for Metals?

[spidey]

Casimir says that there is a force between two neutral metal plates when they are close..suppose if we replace the metal plates with insulators,will there be the same casimir force? what is the difference? why casimir used metal plates,he could have used insulator also?i think insulator is also neutral...

 

[Vanadium 50]

First, Casimir didn't "say" anything. He calculated. I think the distinction is important - theoretical physics is accomplished not by stringing words together in the right order, but through quantitative predictions based on solid calculations.

Second, it matters that the plates are conductors. The key to the calculation is that the field inside a conductor is zero.

Third, I think this uncovers a problem with learning physics from popularizations, which are written for people who have (maybe) had high school physics, but not much more. I was taught the Casimir effect half way through my second year of grad school: so we're talking 5-1/2 years of full-time study beyond where the book is pitched. This is a huge amount og material that's missing, and people are simply going to have to accept that any understanding that's missing this much background is going to be superficial.

 

[spidey]

Second, it matters that the plates are conductors. The key to the calculation is that the field inside a conductor is zero.

Yea..i have only high school physics knowledge..learning from internet..Isn't the field inside an insulator is zero?

 

[Vanadium 50]

No, it's the field inside a conductor that's zero.

 

[tiny-tim]

Hi spidey!

See this thread: https://www.physicsforums.com/showthread.php?t=127262"