Do we have free will? If we don't, we're one step down the metaphysical ladder from fruit flies. Yes, people have determined that fruit flies have free will. And yes, the experimental fly chamber they created to find this out is really freaking weird.
How would you devise a "free will" chamber? If you were doing it for humans, you might do all sorts of things, from constructing a virtual palace with millions of options to simply building a room and seeing whether people will exercise their free will to step inside it. (Meta science.) Or you might skip the question of human free will entirely and try to shrink the problem down to a more manageable size. An ideal size, one group of scientists thought, would be that of a fruit fly. Once that was decided, all they had to do was build a fruit fly free will chamber.
The chamber wasn't a particularly exciting affair. Picture a round room with uniform white light glowing from all the walls. In the middle of this room is a little stalactite, to which is harnessed a fruit fly. Wherever the fruit fly turns, however it moves, it will only see an invariable white light. So the fruit fly can't get anywhere, and is getting no particular stimulus. If the fly is an automaton, it will either follow preprogrammed courses of action repeated again and again, or it will fall into completely random motion as random glitches occur in its brain.
The little stalactite that the fly is tethered to measures its movements. The trick is figuring out whether the movements of a, no doubt, panicked fly indicate random motion, or something more.
After computer analysis, the researchers decided that the fly's motion did indicate something more. Without any stimulus that might guide it into rote mechanical behavior, the flies seemed to be making spontaneous motions which indicated that somewhere, inside their little fly brains, they were deciding how to move based on their own free will. So we have solved one of the great philosophical problems of the ages - but only for flies. Unless you're willing to be tethered to a pillar in a white room somewhere.
Via PLOS One.