As well as being needed to see the world around us, light is very useful in scientific research and industry. Lasers, for example, are used in everything from medicine to entertainment. These bright light sources are also used in scientific research to cool atoms to almost absolute zero or to heat them to billions of degrees Celsius to recreate the conditions at the centre of our Sun. Light is also used to investigate the universe, from looking for tell-tale flash of blue light that signifies the arrival of ghostly particles called neutrinos created by exploding stars to detecting the afterglow of the Big Bang itself.
Light may also help us fight climate change if we can harness it efficiently to generate electricity using solar cells.