5 ms·

What material would this have to be made of to not melt? Edit: I'm not that familiar with radiation and its parameters/properties. My assumption was that it wo

What material would this have to be made of to not melt? Edit: I'm not that familiar with radiation and its parameters/properties. My assumption was that it would accumulate heat. I'll go look up if radiation is a function of heat, then I suppose it could become stable at some temperature. It's surprising to me that you can block out some of the sun from a good area on the earth and not have melting bits.

croisillon 3y ago
i hear it's extremely cold out there
- kvdveer 3y ago
  It is both incredibly hot due to solar radiation, and extremely cold, due to the lack of atmosphere to transfer heat. The sun-side of this parasol will be all melty, while the shade side will be extraordinarily chilly. Whatever it is made of, will need to withstand that extreme thermal gradient.
  - zhirzh 3y ago
    There's also the possibility of occasional space debris or solar flares striking the parasol
    - BizarroLand 3y ago
      Very minor possibility though as any space debris that is not already in a semi-stable orbit would most likely have been filtered out by the planets before making it to any location inside of Earths Orbit, and a space parasol would be fairly small on an astronomical scale.
  - gruez 3y ago
    > It is both incredibly hot due to solar radiation, and extremely cold, due to the lack of atmosphere to transfer heat. If the temperature of the moon is anything to go by, it's hot but not too hot. According to NASA: >Temperatures near the Moon's equator can spike to 250°F (121°C) in daylight, then plummet after nightfall to -208°F (-133°C). https://science.nasa.gov/moon/weather-on-the-moon/ https://science.nasa.gov/moon/weather-on-the-moon/ Something like aluminum foil should work fine.
    - deleted 3y ago
      [deleted]
thsksbd 3y ago
Something with a black back to radiate the heat back out to space. This is (very) stupid.
morsch 3y ago
Mushroom. What other material would a parasol be?
itishappy 3y ago
It's not as hot as you'd think. Solar panels (highly absorbing) reach slightly over the boiling point of water in direct sunlight. Metals work fine, so do a surprising number of composites and plastics. * Aluminum, Magnesium, Titanium, Berylium * Graphite/epoxy, Aramid/epoxy, Glass/epoxy https://www.sciencedirect.com/topics/earth-and-planetary-sciences/spacecraft-structure https://www.sciencedirect.com/topics/earth-and-planetary-sci...
wmf 3y ago
Reflective mylar.
squarefoot 3y ago
> What material would this have to be made of to not melt? I would just use a giant array of solar PV panels as screen, then build a huge coil gun nearby and use all that energy to deflect potential dangerous asteroids by throwing them projectiles made of collected and recycled debris from decommissioned satellites.

croisillon 3y ago

i hear it's extremely cold out there

kvdveer 3y ago
It is both incredibly hot due to solar radiation, and extremely cold, due to the lack of atmosphere to transfer heat. The sun-side of this parasol will be all melty, while the shade side will be extraordinarily chilly. Whatever it is made of, will need to withstand that extreme thermal gradient.
- zhirzh 3y ago
  There's also the possibility of occasional space debris or solar flares striking the parasol
  - BizarroLand 3y ago
    Very minor possibility though as any space debris that is not already in a semi-stable orbit would most likely have been filtered out by the planets before making it to any location inside of Earths Orbit, and a space parasol would be fairly small on an astronomical scale.
- gruez 3y ago
  > It is both incredibly hot due to solar radiation, and extremely cold, due to the lack of atmosphere to transfer heat. If the temperature of the moon is anything to go by, it's hot but not too hot. According to NASA: >Temperatures near the Moon's equator can spike to 250°F (121°C) in daylight, then plummet after nightfall to -208°F (-133°C). https://science.nasa.gov/moon/weather-on-the-moon/ https://science.nasa.gov/moon/weather-on-the-moon/ Something like aluminum foil should work fine.
  - deleted 3y ago
    [deleted]

thsksbd 3y ago

Something with a black back to radiate the heat back out to space. This is (very) stupid.

morsch 3y ago

Mushroom. What other material would a parasol be?

itishappy 3y ago

It's not as hot as you'd think. Solar panels (highly absorbing) reach slightly over the boiling point of water in direct sunlight. Metals work fine, so do a surprising number of composites and plastics. * Aluminum, Magnesium, Titanium, Berylium * Graphite/epoxy, Aramid/epoxy, Glass/epoxy https://www.sciencedirect.com/topics/earth-and-planetary-sciences/spacecraft-structure https://www.sciencedirect.com/topics/earth-and-planetary-sci...

wmf 3y ago

Reflective mylar.

squarefoot 3y ago

> What material would this have to be made of to not melt? I would just use a giant array of solar PV panels as screen, then build a huge coil gun nearby and use all that energy to deflect potential dangerous asteroids by throwing them projectiles made of collected and recycled debris from decommissioned satellites.