Space is cold, about 3°K or -270°C. You’re assuming that you would not radiate heat quickly but that assumption is wrong. I live at about 45°N latitude and the difference between daytime high and overnight low is about 10°C. That’s about 20°C per day. That’s approximately the temperature drop you would feel if you were in space and not in sunlight.
What if you were in sunlight? The Earth’s atmosphere absorbs about half the solar flux. That means anything in near-Earth orbit and is exposed to sunlight will heat up twice as faster as the same object directly in the equatorial sun.
In short, if you were in near-Earth orbit, the side of your suit that is in sunlight will get hot enough to burn you and the side in darkness will get cold enough to cause frostbite. That’s why astronauts in EVA wear underwear with tubing, so that the fluid flowing thru the tube will redistribute the heat and not cause health problems.
I"m afraid that I think you’re in error. You’re comparing it to earth temps – but you’re forgetting that on earth, chilling occurs due to transfer of heat to atmosphere (and via evaporative cooling, since we’re water-based critters), NOT primarily via radiation.
Again, think of a thermos bottle. It doesn’t block IR radiation. It does block conductive loss through the bottle’s sides. There’s a bit of conductive loss through the glass at the neck, and there’s loss through the cap (which is typically less insulated), but that’s it… which is exactly why they insulate.
Space is a huge thermos bottle, with a better vaccuum and no neck or cap. At normal temperatures, we just don’t radiate IR fast enough.
No, the earth’s atmosphere loses heat by radiating heat out to space. When the temperature drops overnight, that’s because the atmosphere is radiating heat to space. If anything, you, being smaller than the atmosphere, will lose heat faster than it.
But wouldn’t rapidly rotating one’s arms in circles (assuming you had the mobility to do so) essentially work on the same principle as a gyroscope, which is what helps keep spacecraft like the ISS oriented correctly? (Disclaimer: physics noob.)
no. spinning your arms would be 1) the wrong axis, 2) not nearly fast enough to matter.
also, the stabilizing effect of a gyroscope comes from coupling the spin and output axes. a free-floating spinny thing will commute torque from one axis to another, but won’t magically stop it (which would violate conservation of angular momentum).
Yes, you can control your spin. Check out astronauts on Skylab doing so. They are pushing off walls and things sometimes, but they are controlling spin at many times in between. True this is not in a vacuum, but air resistance is not what they are using to reorient themselves.
Equations that explain why: F = m a is true in 3D, so there is no way you are getting yourself to start moving back toward your spaceship. But T = I α is only true in specific 2D cases - there are additional terms in the equation in 3D…terms that are very helpful in this situation.
Well, that gradual passing out from mere hypoxia would also be combined with 7.5 hours of contemplating your death. Which may be ok for some people, but not others. I would imagine that astronaut types would probably handle that pretty well though.
