If incandescent lightbulbs have a vacuum inside, why do they get so hot on the outside?
Shouldn't the vacuum insulate the glass from the heat of the burning filament?
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Shouldn't the vacuum insulate the glass from the heat of the burning filament?
Maybe they are thinking of how mugs and thermoses can be labeled “vacuum sealed,” and that the marketing implies that the vacuum between the walls insulates the outer wall (where the hand touches) against the heat.
And those are usually made out of some metal, that'll do pretty good reflecting radiation heat transfer
It does do that though. My vacuum thermos keeps things hot or cold for like 6 hours