I have a lot of thoughts about how science fiction differs from reality. So I will post them here rather than make mulitple posts and spam the forum.
1. The movie Gravity was awesome. For any physics lover.
2. About Waste Heat In Space: I did some research on why spaceships need radiator fins. Well it turns out on Earth we can cool things just by manipulating electric current (the basis of refrigerators). Now you'd think we could carry that into space as a heat sink (we do, but mainly for power), yet there is a huge problem.
As far as we know, it's downright impossible to convert 100% heat into 100% electricity. If through some superhman effort you get 99% of the heat converted into electricity (tell me if any human has managed that, I doubt it), you still have that 1% of waste heat on your spaceship. And that will stay there unless you radiate it away from your spaceship, or cool your spaceship down by coolant.
That 1% of space heat could be very hot, depending on how much heat your converting, and if you have really powerful engines (you need them in space to get anywhere fast), then you do for sure. So radiators or coolant are the only realistic way to go.
That said, radiators and coolant are curiously absent in popular science fiction on TV.
So that means something. The writers ignored it, but I will think of some way their spaceships could manage waste heat, since they never bothered to explain.
Star Trek/Star Wars ships somehow covert 100% of the heat from their engines into electricity. I suppose that may be reasonable, if you consider that their tech is supposed to be more advanced.
Whether or not it's possible is up in the air. It's safe to say that if we ever manage that, Earth's energy problems will be a thing of the past likely.