Skydiver Felix Baumgartner breaking sound barrier for Red Bull Stratos. Talk about extreme. Whether people question whether skydiving is a sport or not, it certainly is challenging and requires strong technique.
The Exact Moment of a Sonic Boom. An Air Force Raptor executes a supersonic flyby over the flight deck of the aircraft carrier USS John C. Breaking the sound barrier. Military jets used to do this all the time over our house in rural Maine.