Why is it that dizziness happens in the head but makes us unstable on our feet? Blame the vestibular system – the sensory system that perceives our motion in space in relationship to gravity.  The sensors themselves are located in the inner ear, but the information they provide is critical to perceiving and maintaining our vertical alignment with gravity as we move around in the world. And that matters for more than not falling down. Gravity affects every breath we take,…