Scientists capture footage of a sonic boom of light for the first time

Scientists capture footage of a sonic boom of light for the first time

A laser was fired down a tunnel to create the sonic boom

Tuesday, January 24, 2017

Scientists have captured footage of a sonic boom of light for the first time ever. 

Jinyang Liang and Lihong V Wang from Washington University were able to do this by using use a custom-built camera which records frames just a trillionth of a second apart.

The camera is so quick it is capable capturing processes in the human body, such as neurons firing in the brain.

However this time it captured something called a photonic mach cone, otherwise known as a sonic boom of light, BT said.

Although objects cannot travel faster than the speed of light, it can be slowed down, which is how the boom was created.

Scientists fired green lasers down a tunnel through dry ice between two plates of silicon rubber and powdered aluminium oxide.

Light passes through the silicon plates slower than dry ice, so the laser scattered specks of dry ice within the tunnel, which generated light waves to enter surrounding plates.

The laser travelled faster in the tunnel than in the plates, meaning a laser pulse moved down the tunnel, leaving behind a cone of slower-moving overlapping light waves in the plates.


This can be compared to a sonic boom of sound. In such a case, the mach cone is made up of sound waves which form around an object travelling faster than the speed of sound. 

For example when jet engines do this, the loud bang we hear is a sonic boom, caused by sound waves being compressed in the mach cone.