National Ignition Facility fires record laser shot—…a milepost on the way to fusion energy.

[napoleon_in_rags]

7. The real question: is photosynthesis without sunlight natural?

No! That's the key, we're talking about SOURCES of energy. When something is a source of energy, meaning you can get energy out of it without having to pour more energy in than you get out.

A 200 lb rock on the edge of a cliff has the potential to do work. (it has low entropy) You could, for instance tie a rope to it, attach it to pulley, and use it to pull your 150 lb friend - tied on the other end of the rope - up to the top of the cliff, so you don't have to do the work. However, once that rock is at the bottom of the cliff (high entropy) you can't get it back by tying your friend to the rope again and having him slide down, the rock weighs more than him. The only way to get it back is to pour in more weight than you did the first time, like by finding a 250 lb rock.

Water is the rock at the bottom of the cliff, its the high entropy state for hydrogen and water. Like the rock you CAN get it back to the top of the cliff (separate hydrogen and water) but it takes more energy than you got out from having them burn (go to the bottom of the cliff)

What we're looking for are the proverbial rocks on cliffs, things we can actually get energy from.