Comment on Ultra-white ceramic cools buildings with record-high 99.6% reflectivity

• schmidtster@lemmy.world ⁨11⁩ ⁨months⁩ ago

  Where it has to pass through the atmosphere again? With more time to heat up the atmosphere as well?

  The answer isn’t this simple, I’m curious why people think they could answer it in a sentence or two.

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  • ExLisper@linux.community ⁨11⁩ ⁨months⁩ ago

    Radiation is not absorbed by transparent gases. The ground is heated and air heats up by contact. It’s a well known fact that snow radiates back the heat and lowers the overall temperature. That’s how ice age works.

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    • schmidtster@lemmy.world ⁨11⁩ ⁨months⁩ ago

      Sure, but there is more than just transparent gases, there is also some solid objects.

      No that’s not a well known fact at all since it’s not even remotely correct… that has more to do with the sheer amount of ice cooling the planet than diffusion reflection.

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      • ExLisper@linux.community ⁨11⁩ ⁨months⁩ ago

        Of course it will affect stuff: it will cool it down. It’ really very basic. Scenario 1:

        • bunch of photons (energy) comes from space
        • hit the earth and heat it up
        • the heat is transferred to air by contact
        • the air heats up

        Scenario 2:

        • photons heat white surface and are scattered around
        • some scattered photons will hit other things but not all of them, most will just fly back into space without transferring energy
        • the white surface doesn’t heat up as much as ground
        • less heat is transferred to air bu contact
        • air is cooler

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  • doggle@lemmy.dbzer0.com ⁨11⁩ ⁨months⁩ ago

    If the light hits the ground and is scattered then nearly all of the energy stays in the planet and eventually heats the atmosphere. If it’s reflected, even though it must pass through the atmosphere again, some of the energy is rejected back into space.

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