Sound travels at about 760 miles per hour. When a jet reaches close to those fast speeds it can cause some remarkable visual and acoustic effects. As you will see in this video, when the aircraft passes the sound barrier it is almost like hitting an invisible glass wall. The sonic boom you hear (similar to thunder) is caused by a pressure differential caused by compressibility of air near the speed of sound, in other words the air can’t move out of the way quick enough and causes a wave of pressure to build up.

