# What happens to Capacitors at extreme temperatures and pressures?

In my University physics class [first year engineering student] I learned that

"for a capacitor in a vacuum, capacitance $$C$$ depends only on the shapes, dimensions, and separations of the conductors that make up the capacitors".

Does this mean that the vacuum makes material properties null.

This statement, which, with my current knowledge of physics I do not believe in, due the questions I have specifically relating to material and temperature which I thought would have been important. I wanted to focus on temperature first with my questions, so I was wondering the following:

Given a capacitor in a vacuum what would happen at extreme low temperatures and high temperatures?

And how would this differ from what would happen not under a vacuum, how would pressure affect capacitance.

• Are you considering a capacitor with vacuum as the insulator or some other dielectric?
– Puk
Commented Feb 21 at 3:58
• With the vacuum as the insulator. Thank you. Would the answer change if it was a dielectric, if so what materials would result in different results on the capacitor? Commented Feb 21 at 4:08
• @WilliamBanquier hyperphysics.phy-astr.gsu.edu/hbase/electric/dielec.html Commented Feb 21 at 4:14
• @WilliamBanquier Yes, dielectric constant (permittivity) is a function of temperature in general. I don't know what this dependence looks like for specific materials, but a key term is "temperature coefficient of capacitance" if you want to delve deeper into that.
– Puk
Commented Feb 21 at 4:16
• Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking.
– Community Bot
Commented Feb 21 at 4:17