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What, exactly, do you think is cold? What happens when you put something hot into a vacuum-encased thermos, and why? (I also don't mean to sound patronising.)

It wouldn't freeze solid upon ejection. Do you have a link for that? You get a lot of surface area, and the presence of a decent vacuum means that much of the liquid will vaporize - essentially a lot of evaporation. That takes the high-energy particles away. Anything left over is going to be significantly colder. That part might freeze pretty quickly.

Q: Before signing the death certificate had you taken the man's pulse? -- A: No. Q: Did you listen for a heart beat? -- A: No. Q: Did you check for breathing? -- A: No. Q: So when you signed the death certificate you hadn't taken any steps to make sure the man was dead, had you? A: Well, let me put it this way. The man's brain was sitting in a jar on my desk, but for all I know he could be out there practicing law somewhere.

But you have only radiation to transfer heat and at ~310 K that's fairly inefficient.

Heat loads are a concern, but really only when you are dissipating several Watts. Radiation heat transfer goes as the difference of T4, so small amounts of power, like a flashlight, shouldn't be much of a problem. (It's also possible to use flashlights that don't rely on a blackbody source, e.g. LEDs, but I have no idea if there are space-qualified versions of these) Ventilation fans don't do you any good in a vacuum. For larger loads you do liquid cooling, but generally a lot of your engineering is getting the total power consumption down. The limited power available to you drives that at least as much as heat dissipation does.

The cosmonauts of Soyuz 11 died after a valve inadvertently vented their capsule. They were not wearing spacesuits, and died of asphyxiation. They did not explode. Also a NASA employee was accidentally exposed to very low pressure. He felt the water on his tongue boil as he lost consciousness. Here is what NASA has to say on the subject.

Water not contained in cells and tissue does.

The latent heat is how much energy you need to add, per unit mass, to melt the ice at 0 C. The specific heat is the energy required, per unit mass, to change the temperature. You know the final mass and temperature and that energy is conserved.

I think perhaps you meant 30,000 km/s, which is approximately light speed. You couldn't actually travel that fast, but at whatever speed you actually were going, light would still travel at c relative to you - you can't tell that if you are moving or if everything around you is moving, if you're in an inertial frame of reference. As far as you can tell, you are stationary, so there's no problem there. As YT said, the mirror isn't moving relative to you, so that's not an issue. The strange stuff happens for other inertial observers. They see you movong fast, and they also see light travelling at c, but they will see the frequency of that light change, as well as lengths contracted and time running slow for you. A lot of strange things become apparent once you realize that c is invariant.

I do physics research, and my job requires a PhD, simply because you can't currently get the relevant exerience anywhere else. But lots of research establishments have internships; it depends on the specific job. I know of programs that take in high school students and others that take college students to do work for a semester or for the summer. College internships often don't pay much (or anything) but you get course credit for it.

I don't think you'd get an explosion, per se, for a gas, because the relevant effect is diffusion. Any given molecule doesn't "know" if it's in a gas at atmosphere or in a vacuum. It just travels and maybe undergoes a collision after a bit. The trend is to diffuse from high density to low density - the effect is nowhere near instantaneous. When you vent a vacuum system to atmosphere it takes a while, depending on the size of the hole you've made, for the system to equilibrate.

Chances are the gammas would ionize electrons rather than excite the nuclei, though the nucleus will recoil slightly when the atom is ionized. The electrons then cause secondary ionizations and emit Bremsstrahlung as they scatter, all the while any given electron has less and less energy. But you're right in that it all eventually shows up as an increase in temperature. Plus, lead attenuates according to an exponential; you wouldn't shield all of the original radiation. Some would escape.

Deuterium + Deuterium = tritium + proton + 4 Million electron-Volts

From the bird.

No, if you were exposed to vacuum for a length of time, you would most decidedly NOT explode. Some tissue damage might occur from your compulsion to exhale, but that's not the same thing. You's asphyxiate after a short while. Your body is mostly water, the coefficient of expansion for water is really, really small, and it's only a 1 atm difference in pressure. Diving to 30 ft doesn't crush you for similar reasons.

Holding your breath would be tough, and possibly cause damage. I don't think it would be particularly bright - not much different than a moonless night away from light pollution here on earth.

I'm Tom, and I'm a geek. I get to play with really expensive toys that someone else pays for, i.e. I'm an experimental physicist.

Or you could store that info in an emulsion or charge-coupled device, and print the likeness out on a sheet of paper. Nah, it'd never sell.