Energy in a Vacuum?

Suppose you have an absolute vacuum, with zero particles, and its container is made of a conductive material, like a metal or something, which is heated. What happens inside the vacuum?

Does heat need the medium of air, or will it heat the vacuum? I reason that heat needs a medium (like air particles) to permeate because the particles vibrate, transferring the energy that is registered as heat, but this doesn't seem right. I know that space isn't a perfect vacuum, but it's close enough, and heat from the sun reaches the earth. I guess what I'm ultimately wondering is, does heat (or any form of energy) need a medium to travel through, other than space?

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DaveC426913
Gold Member
Suppose you have an absolute vacuum, with zero particles, and its container is made of a conductive material, like a metal or something, which is heated. What happens inside the vacuum?

Does heat need the medium of air, or will it heat the vacuum?
The vacuum will not heat up. The container will radiate heat, sending EM radiation (photons) from its inside surface through the cavity to the other inside surface.

I reason that heat needs a medium (like air particles) to permeate because the particles vibrate, transferring the energy that is registered as heat, but this doesn't seem right. I know that space isn't a perfect vacuum, but it's close enough, and heat from the sun reaches the earth. I guess what I'm ultimately wondering is, does heat (or any form of energy) need a medium to travel through, other than space?
There are many things that transfer heat. It can be passed kinetically, via particles (conduction) and it can be passed through vacuum (radiated), via photons.

Hi,
I don't my concept is clear or not.
please clear this doubt.
Em radiation doesn't required medium to propagate but it carries energy(e.g-light).
as the energy is transmitted so the vaccum may be heated.

as the energy is transmitted so the vaccum may be heated.
The energy is transmitted to what?Generally there's air which vibrates
However,http://en.wikipedia.org/wiki/Vacuum_energy" [Broken]

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how would we know if the vacuum heats up or not?
doesn't vacuum mean there is nothing there. If there is nothing there, what would heat up?

how would we know if the vacuum heats up or not?
doesn't vacuum mean there is nothing there. If there is nothing there, what would heat up?
I think Dave explained what would happen

HallsofIvy
Science Advisor
Homework Helper
Hi,
I don't my concept is clear or not.
please clear this doubt.
Em radiation doesn't required medium to propagate but it carries energy(e.g-light).
as the energy is transmitted so the vaccum may be heated.
EM radiation passes through the vacuum. If there is nothing in the vacuum for the EM radiation to affect, then it will not be heated.

The OP, in respectful rebutal might ask...(OK, my words, sorry)

Are virtual particles affected by non-virtual EM radiation?