Have you ever wondered how Olympic divers, with their tumbles, flips, and swirls, swan so gracefully into the pool from ten meters above? We don't want to kill the magic, but it's mostly physics.
It all starts with that initial jump, either from a springboard 9.8 feet (three meters) above water or a platform 32.8 feet (ten meters) above water. In less than two seconds, divers are able to squeeze a couple flips and a rather small splash into their performance.
That very first leap needs to take the form of an arch, according to this video by DNews (Discovery News), so that the diver ends up several feet in front of where he or she jumped. The height from which they leap also determines how many tricks they can do before hitting the water.
To increase the speed of a flip as they fall toward the water, divers crunch their bodies into compact balls to reduce the "moment of inertia," or the tendency to resist accelerated, angular momentum. This helps them execute more flips in less time.
Another way to increase spin-fall speed is the "pike", in which the legs are straight and the arms wrap behind the knees. This position is more difficult because the diver has less control over his or her rotational speed, the video explains.
To finish off the dive with a high score, divers also need to keep their splash at a minimum. Rather than causing what would be the expected explosion of an object traveling at 30 miles per hour dropping into a pool of water, divers need to subtly just pierce the water's surface. This technique is called a "rip entry", and is achieved by entering the water from as straight a position as possible.
Understanding the physics of movement and how the body enables certain positions is behind all Olympic divers. The skill and grace blows the average belly flop, literally, out of the water.