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Gravity in the Brain
Playing catch looks easy, but there's more to it than meets the eye. A ball-catching experiment in space has revealed that human brains have a built-in model of gravity.
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March 18, 2001
Playing catch is easy. Kids and
even their parents can do it. Keep your eyes on the
ball and -- if you don't think too hard -- your hand
will grab it in mid-air. It's simple, really.
Or is it? In fact, playing catch is more complicated than it appears.
Just before the ball arrives, your hand twists slightly. The muscles tense, so your hand isn't knocked away by the force of the blow. The timing is surprisingly exact: the muscles tighten exactly one-tenth of a second before the ball's impact.
Playing catch.
Image credit and copyright: Jim Richardson.
The brain prepares for the catch even earlier. The hand moves only because the brain tells it to -- and it takes two tenths of a second for the brain's commands to travel down to the hand. Such delays require the brain to predict when the ball will arrive -- a process made more difficult because, due to gravity, the speed of a soaring ball is always changing.
How does your brain do it?
(Full Story Here)
Cheers,
Dan
Gravity in the Brain . . .