Comment on The sun is a deadly laser...
Mesophar@pawb.social 2 days agoAre you dissipating heat in a vacuum, though? Pressure shenanigans aside, would someone’s body heat slowly, continually build up, or would they freeze?
If you could somehow prevent yourself from dying due to lack of pressure, you would radiate about 650W more than you generate.
That’s using the Stefan Boltzmann law, at normal body temp, perfect blackbody and 1.5m2 of skin. And then assuming 2000kcal a day.
You’d cool down pretty quickly.
So how long do I have? Also, if you guys could hurry with the answer…?
I can’t really find a good number for how cold you can get and not die, so let’s say 20 degrees. That gives 16 degrees.
Meat has a specific heat of about 3.5kJ per kilo per degree, so say you weigh 70kg, that’s about 4 million joules to lose before you die.
At 650 joules per second, you’ve got slightly over 10 minutes.
Your skin isn’t at core temp tho, so the loss rate should be lower I think
Meat has a specific heat of about 3.5kJ per kilo per degree, so say you weigh 70kg, that’s about 4 million joules to lose before you die.
At 650 joules per second, you’ve got slightly over 10 minutes.
My man, first of all
4,000,000/650/60=102.57 minutes
And that’s with your math based on an imaginary object. A body is going to lose heat far more slowly.
Also, you forgot one important aspect, if you’re getting bathed by the sun and spinning, you’re constantly getting heated up.
Good to know! I didn’t realize humans would radiate heat so much, I wrongly assumed it was more convective and relied on atmosphere
Heat buildup is actually a problem in space, yeah. You need heat sinks on long term space flights.
You constantly radiate heat. The warmer you are, the faster you radiate it away. In space this does not stop.
Have you ever looked up at a clear summer night sky? Your face will feel cold. Colder than when looking at the ground. That’s because there’s not as much stuff radiating heat at you up there.
It would be pretty warm at earth if the planet didn’t radiate some of the heat away
ExperiencedWinter@lemmy.world 2 days ago
en.wikipedia.org/wiki/Black-body_radiation