almost two tenths of a second. (In fact, if they move off the blocks before that duration, they’re disqualified – they’ve “jumped the gun”.) Athletes train to make this gap as small as possible, but their biology imposes fundamental limits: the brain has to register the sound, send signals to the motor cortex, and then down the spinal cord to the muscles of the body. In a sport where thousandths of a second can be the difference between winning and losing, that response seems surprisingly slow.
