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JoshuaZ comments on A sense of logic - Less Wrong
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People might feel better about this entry if it were in the discussion section rather than in the main section. Also note that one needs to be careful about focusing on such arguments. Reversed stupidity is not intelligence. Moreover, the argument you mention about faster than light travel has non-trivial forms. A classic puzzle given to beginning physics students is very close to this, where one has a laser beam that is focused on a very far away object. If you move the laser pointer a little bit the dot will move much faster than the speed of light. The problem is to explain why this doesn't violate special relativity.
My point wasn't to propose Sturgeon's argument, it was to encourage people to observe how they react to obviously bad arguments, and to get some thoughts about how cognition is connected to the body as well as the brain.
Right. You might answer that the dot is not actually reaching the stars, and so is not traveling faster than the speed of light.
A similar problem, though, is a thought-experiment with a rigid rod which is one light-year long. If you rotate it with yourself as the axis, at even a small angular velocity, explain why the tip doesn't go faster than the speed of light.
I'm guessing that "rigidity" is actually a complicated engineering sort of thing when you really look at it, so that the motion takes time to propagate down the rod.
Yep. If you tried to rotate a giant rod, it would look like a spiral.
Galaxies have much looser internal connections than a rod has.
However, this suggests that light speed puts an upper limit on the rigidity of materials.
The galaxies were just there as a visualization- I don't think they started out as rods (but I Am Not An Astronomer).
Yep- the fundamental mechanism underlying rigidity is the electromagnetic potentials between atoms, and those can't propagate faster than the speed of light. Typical speeds of actual propagation are significantly slower- vibrations travel at the speed of sound in that material, and so on.