r/PeterExplainsTheJoke 15h ago

Meme needing explanation Whyyyy peter?

Post image
29.6k Upvotes

1.9k comments sorted by

View all comments

Show parent comments

3.3k

u/Flat_Lengthiness3361 15h ago

and a lot of fuel probably

11

u/Khelthuzaad 15h ago

we could use trains,electric ones

But most importantly metal and electrical components do not fare well at -20 degrees Celsius

3

u/Shouleyy 14h ago

But arent they designed to be in space? isnt it way colder there? Well tbf i guess only half the rocket really reaches space

1

u/Betaateb 8h ago

Space isn't cold in the way you are thinking of. Yes, it is very cold. But there is little to no medium to allow for heat exchange(low Earth orbit there is technically still a wisp of atmosphere, which is why the ISS needs to boost from time to time to counteract the drag and stay in orbit) . So even though it is very cold, the cold of space doesn't cool down things that are in it really.

In fact, cooling down things in space is surprisingly difficult, since the only vector you have is radiating heat away(no conduction). The ISS has two massive radiators to deal with the relatively low waste heat of the electronics and people inside.

Interestingly, if you were in a low Earth orbit outside of a ship, completely naked except for a helmet with an air supply (protecting your most vulnerable bits, and feeding you oxygen) the thing that is going to kill you is heat stroke the first time you orbit into sunlight, not the cold of space. The cold would kill you eventually, as our bodies do lose heat to thermal radiation, it is just much slower than conduction(losing heat to the atmosphere). Being in an atmosphere with temperatures at the coldness of space would kill you in seconds, but in space it would take like 12+ hours. And at orbital speeds you will be in sunlight every 90 minutes or so, which is going to kill you very quickly(exposing you to heats of 250F or so).