4 ms·

Well if we transform solar into electric then into motion or bound carbon, that should actually help reduce the heat balance?

codethief 5y ago
> into motion Kinetic energy will end up getting converted to waste heat nonetheless. > or bound carbon This seems hard to imagine. We're dealing with waste energy here, so a very high-entropy type of energy. Bound carbon is low-entropy, so the conversion is impossible[0] unless we put that entropy elsewhere. As an analogy, consider a fridge: It brings your food from a high-entropy (high-temperature) to a low-entropy (low-temperature) state but in order to do that it also has to produce waste heat (entropy) on the outside. [0]: https://en.wikipedia.org/wiki/Second_law_of_thermodynamics https://en.wikipedia.org/wiki/Second_law_of_thermodynamics
- regularfry 5y ago
  We're not necessarily talking about a closed system, though. If you've got an energy supply that rounds to limitless, constructing planet-scale heatsinks starts to look tenable.
  - codethief 5y ago
    > We're not necessarily talking about a closed system, though. Short of shooting hot lava into space[0] we pretty much are because, once again, thermalization through radiation is governed by Stefan-Boltzmann's law and there's no way around that. [0]: https://news.ycombinator.com/item?id=28468182 https://news.ycombinator.com/item?id=28468182
    - regularfry 5y ago
      Stefan-Boltmann talks about emission per surface area. So... increase the surface area. We're not limited to a sphere. The same problem crops up when you're talking about moon bases and so on - you've got the same problem of venting heat from an ecosystem into a vacuum. For that situation, one of the solutions that got designed out was to basically spray an oil mist across a gap, catch it, and recycle it into the cooling system. As a fine mist, the oil has a colossal surface area compared to its mass, and all that surface area can radiate heat off into the vacuum. So... scale that up? I realise it's a hell of a leap, to go from human-scale to humanity-scale, and I don't know exactly what it would need to look like, but limitless energy is a hell of a springboard.
goodpoint 5y ago
Absolutely yes. Energy is captured by solar panels. They make a shade, obviously, and what is in their shade does not get heated by the sun. If you were to use 100% of solar panel energy to heat up something else the overall balance would be 0. Contrarily, nuclear fission/fusion that releases energy from its fuel, ultimately heating up the planet.
acchow 5y ago
But then what do you do with that motion? Eventually it all decays to heat, as per the 2nd law of thermodynamics

codethief 5y ago

> into motion Kinetic energy will end up getting converted to waste heat nonetheless. > or bound carbon This seems hard to imagine. We're dealing with waste energy here, so a very high-entropy type of energy. Bound carbon is low-entropy, so the conversion is impossible[0] unless we put that entropy elsewhere. As an analogy, consider a fridge: It brings your food from a high-entropy (high-temperature) to a low-entropy (low-temperature) state but in order to do that it also has to produce waste heat (entropy) on the outside. [0]: https://en.wikipedia.org/wiki/Second_law_of_thermodynamics https://en.wikipedia.org/wiki/Second_law_of_thermodynamics

regularfry 5y ago
We're not necessarily talking about a closed system, though. If you've got an energy supply that rounds to limitless, constructing planet-scale heatsinks starts to look tenable.
- codethief 5y ago
  > We're not necessarily talking about a closed system, though. Short of shooting hot lava into space[0] we pretty much are because, once again, thermalization through radiation is governed by Stefan-Boltzmann's law and there's no way around that. [0]: https://news.ycombinator.com/item?id=28468182 https://news.ycombinator.com/item?id=28468182
  - regularfry 5y ago
    Stefan-Boltmann talks about emission per surface area. So... increase the surface area. We're not limited to a sphere. The same problem crops up when you're talking about moon bases and so on - you've got the same problem of venting heat from an ecosystem into a vacuum. For that situation, one of the solutions that got designed out was to basically spray an oil mist across a gap, catch it, and recycle it into the cooling system. As a fine mist, the oil has a colossal surface area compared to its mass, and all that surface area can radiate heat off into the vacuum. So... scale that up? I realise it's a hell of a leap, to go from human-scale to humanity-scale, and I don't know exactly what it would need to look like, but limitless energy is a hell of a springboard.

goodpoint 5y ago

Absolutely yes. Energy is captured by solar panels. They make a shade, obviously, and what is in their shade does not get heated by the sun. If you were to use 100% of solar panel energy to heat up something else the overall balance would be 0. Contrarily, nuclear fission/fusion that releases energy from its fuel, ultimately heating up the planet.

acchow 5y ago

But then what do you do with that motion? Eventually it all decays to heat, as per the 2nd law of thermodynamics