this post was submitted on 14 Nov 2023
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Ultra-white ceramic cools buildings with record-high 99.6% reflectivity::undefined

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[–] schmidtster@lemmy.world 4 points 1 year ago (3 children)

So there’s gotta be a downside to reflecting all this heat though?

I know windows sometimes can focus and reflect the sun setting your neighbours house on fire, birds aren’t going to affected, bugs?

[–] pennomi@lemmy.world 14 points 1 year ago (1 children)

It looks like this reflects and scatters the light, rather than reflects and focuses it. Otherwise it would look like a mirror, not a ceramic.

[–] schmidtster@lemmy.world -4 points 1 year ago

That would only matter for something that it can focus on, it’s still reflecting. All the heat and at scale it’s not tested.

Adding more heat and heat currents into the atmosphere, cannot be a good thing long term.

[–] ExLisper@linux.community 2 points 1 year ago (1 children)

Not if it's reflected back into space.

[–] schmidtster@lemmy.world -2 points 1 year ago (2 children)

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.

[–] ExLisper@linux.community 2 points 1 year ago (1 children)

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.

[–] schmidtster@lemmy.world -1 points 1 year ago* (last edited 1 year ago) (1 children)

Sure, but there is more than just transparent gases, there is also some solid objects. Those would be heated by outgoing radiation. There is also convection currents that can affect weather and migration patterns…

That’s one part of it yeah, and there is absolutely no scientific data on the resulting reflection issues. It’s also funny that ice age answer kinda proves my point, if sheets of ice can make an ice age worse… yeah coating a bunch of stuff with this will absolutely affect stuff. And you are claiming it won’t? Because this answer directly contradicts your previous ones….

Can I see your sources I’m actually quite interested in this and I’m surprised people are answering this with grade school level answers that aren’t even close to being correct.

[–] ExLisper@linux.community 1 points 1 year ago (1 children)

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
[–] schmidtster@lemmy.world 0 points 1 year ago* (last edited 1 year ago) (1 children)

And all the greenhouse gases it will heat up as it passes through them? You can’t just ignore these gases…

It’s not that simple, and you claiming it is show you have zero understanding of the potential issues. Your ice age example shows that it can affect the globe at scale. Thank you for part of the answer, I’m surprised you’re still arguing after proving my point.

[–] ExLisper@linux.community 1 points 1 year ago (1 children)

I'm not arguing it's not going to affect the globe at scale (even though you would have to cover shitload of building in this to affect it). I'm saying that we know what the effect would be: it would cool it down.

What you fail to understand is that if solar radiation hits a dark surface, like a roof, this energy is transferred to earth. That's it. It's here. Now it's really difficult to get rid of it. Greenhouse gases make this even more difficult.

But if solar radiation hits a white surface SOME of this energy will be reflected back to space. Not ALL of it, some of will still stay here but overall it will LESS energy.

Greenhouse gasses trap the radiation emitted by earth as heat, not the reflected light. Think about it. If greenhouse gases reflected light then we would get less light from the sun, right? Part of it would be reflected. They don't do that. They let light pass through and stop the heat radiated from earth. If you reflect light instead of trapping it that's a good thing.

This is so basic I'm starting to suspect you're just trolling so I will end this conversation here...

[–] schmidtster@lemmy.world 0 points 1 year ago* (last edited 1 year ago)

I understand that fine…

Green house gases absorb radiation unlike transparent gases. It directly refutes one of your claims since they exist at the same time. Why are you talking about reflection here…?

You clearly don’t know enough to answer the question correctly. And you completely incorrectly explaining greenhouse gases and how radiation affects it just proves it all the more. Have a great day, I’m sorry you thought you knew more than you thought here. It happens.

You claim it’s basic, yet each of your “basic” points have easily been refuted by going to intermediates, it’s not as simple as you claim it is… and you claiming it is also just shows you have zero credibility understanding of the subject.

So who’s the troll here? The one getting flustered from having their “basic” explanations refuted with just as basic science, or the one contesting with examples that show it’s not actually that basic…?

[–] doggle@lemmy.dbzer0.com 0 points 1 year 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.

[–] doggle@lemmy.dbzer0.com 0 points 1 year ago

If the top of my head

  • it cools your house in the winter, too
  • It's probably annoyingly bright if you can see the roof from ground level
  • likely to degrade over time necessitating replacing tiles to maintain the effect
  • Doesn't work as well if you've got solar panels or trees obstructing it
  • other stuff, probably