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I don't mean to turn this thread into Ask Choobus, but here's something I don't understand: momentum and its relationship to energy. My brother used to be a weapons engineer for GD, and once he was trying to explain to me why it's so hard to make an energy weapon like a weaponized laser. He invoked E=m2c4+p2c2 and said that matter is like concentrated energy. He said that when you fire a piece of matter at something, it's like firing a whole ton of energy, and to get that much energy out of a laser requires hundreds of megawatts.
But, if you take the amount of gunpowder in a pistol cartridge, and combust it in a chemical laser, the laser has far less energy than the impact energy of the bullet. If the extra energy in the bullet situation comes from the mass of the bullet, as my brother seemed to imply, why isn't the energy used up, instead of being available to be shot off again with another amount of gunpowder that couldn't even power a laser pointer?
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