Why does light travel faster than sound?
Asked by: Toby Graham, Shrewsbury
According to Einstein’s Special Relativity, the speed of light has a unique status: it’s a fundamental feature of our Universe, representing the maximum speed at which information can travel from place to place. As such, nothing can match the 300,000km/s achieved by light travelling through a vacuum – least of all sound, which being waves of compression and expansion in a substance doesn’t even exist in a vacuum.
That said, light can be slowed down by being passed through transparent materials – by around 33 per cent in the case of glass. Even so, it still zooms through glass around 50,000 times faster than sound waves.