Fish 40

Mains electricity is so much higher. Isn't it possible to have a 250W (mains 'lec in UK, not sure about the US) homemade laser? That sounds ridiculously dangerous.

Is the proof that space is being created the fact that relativity is proven, therefore expansion must be due to space being stretched/created, otherwise the galaxy movement would violate relativity?

This might be going way out into the speculative, but if you REALLY wanted a super sword instead of just using guns like a sensible person, then what about a meta-material used in an electrically operated sword that is able to channel energy to the edge, like a more advanced version of a hot knife? There already are in existence various kinds of meta-materials which can bend light in interesting ways. Is it possible to make one which can generate a focused laser like effect at the very edge of the material when provided enough energy?

I'm pretty sure this would only work with a material that was way stronger than anything else. The materials would let you down and the edge would be more likely to break the thinner it is, so it would seem as though you would need a material vastly stronger than any known to make this work as described.

Either is interesting. I chose volume, because I think it makes a better comparison between vehicles of the same size fitting different fuels in the same tank, assuming hypothetically that the system can run all these fuels (A real car/truck wouldn't). Obviously mass is important, but it seems like the chart I found has most fuels clustered near each other in terms of energy to mass. Hydrogen being a BIG exception. Looking on Wikipedia (how do you link?), it seems that Aluminum has the greatest energy to volume ratio (Hydrogen has the greatest energy to mass ratio), so with the assumption that some day you could extract that energy as quickly, you get more than twice the power you get from Diesel. Course, just because that may be true it doesn't mean that it's the highest in theory, just as diamond is not the hardest -possible- material. I was guessing it was possible to determine this limit based on the bonds, but I'm not much good at math.

So there's no way to determine how much more powerful fuels can get in the future?

I know there's a limit to energy production full stop in matter-antimatter pair annihilation, but what is the limit for just chemical energy? If I have a box of one meter cubed, what's the maximum amount of energy extractable chemically by the laws of physics?