intensely_human, 11 months ago Heat radiates as infrared light. Infrared doesn’t pass through glass well, so the glass absorbs the heat radiated from the filament. Heat passed through molecular collisions is conduction, and that is the part blocked by a vacuum. So the filament is emitting visible and infrared and the bulb is designed to let the visible pass through.
Heat radiates as infrared light. Infrared doesn’t pass through glass well, so the glass absorbs the heat radiated from the filament.
Heat passed through molecular collisions is conduction, and that is the part blocked by a vacuum.
So the filament is emitting visible and infrared and the bulb is designed to let the visible pass through.