Playing Ball in Space

oo7tushar writes "Although most experiments in space seem simple they have profound results. Take this for example, astronauts trying to catch a ball in space. What's so hard about that? Nothing much really, down here on Earth. In space it's a completely different story. Here on earth our eyes see the ball and our brain anticipates it's movement according to gravity. In space the brain continues to anticpate gravity but unlike motion sickness (which is adapted to within days), astronauts continue to anticipate the path of a ball for 15 days (after which they start to show progress). What are the ramifications? The brain must have some sort of internal gravitation model."