heat is movement of atoms and molecules.
Moving atoms don’t physically touch each other. They transfer their momentum with photons.
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Thorry@feddit.org 1 day agoWell that’s just objectively wrong. Light is EM radiation, where heat is movement of atoms and molecules. Via incandescence objects can radiate away their heat (following black body radiation), however they are not the same thing.
Blue_Morpho@lemmy.world 1 day ago
ivanafterall@lemmy.world 1 day ago
Wtf, is that true? Aren’t photons weightless? It’s all black magic.
BakerBagel@midwest.social 1 day ago
What happens when photons emittes from the heater hit items in the room? That energy is imparted into the object, heating it up.
azertyfun@sh.itjust.works 1 day ago
If we’re going to be pedantic, let’s do it correctly.
Even with the blinds shut, a space heater will emit a surprisingly large amount of radio waves (mine actually disrupts USB devices with a small EMP when it turns on, and anyone with an RTL-SDR can tell you those 50 Hz harmonics are rough). Some of those radio waves will penetrate the walls/blinds and a tiny fraction might escape the atmosphere and head off into space. From there some will find their way to interstellar space and potentially drift “forever” (well, until the heat death of the universe or whichever theory you subscribe to; I think at that point saying “the photon never got converted into heat energy” is a good enough approximation).
HugeNerd@lemmy.ca 1 day ago
Yes, nothing like a sine wave in a resistor to create those harmonics.
usrtrv@sh.itjust.works 1 day ago
So then you state: The light will become heat energy.
Thorry@feddit.org 1 day ago
Sure, but like the other commenter said, everything turns into heat eventually
BakerBagel@midwest.social 1 day ago
So the heater takes all energy you put into it and turns it into heat at a 100% efficiency
smoker@lemmy.zip 1 day ago
The heat isn’t transmitted via photons, it’s transmitted via convection. The air acts as a medium to transmit the heat energy outward. The heating element itself emits photons because it gets hot enough where the atoms within vibrate at a frequency which reaches the visible spectrum of light. That’s why cooler elements glow red (lower frequency) and hotter elements glow blue (higher frequency). Most of the heat energy is not contained in the photons, you need an output on the level of the sun to achieve that. With regards to the sun, all of the energy is carried by radiation anyway, because convective currents can’t travel in the vacuum of space.
Cethin@lemmy.zip 1 day ago
They didn’t say most of the heat was carried by photons. They said the photons turn into heat when they’re absorbed by atoms. That’s how radiative heat works, and yeah, most of the heat from a space heater isn’t radiative, but some is. All of the light you see turns into heat, so it isn’t lost. A tiny fraction will be lost through some means, but approximately 100% is turned into heat at some point.