Lasers are useful for all sorts of things, including spectacular light shows, no wonder there was a huge argument over who invented them.
Lasers produce a constant stream of photons (units of light) in a single frequency, which means the light can be controlled and used in different ways. Albert Einstein came up with the theory behind lasers in 1916, but it wasn’t put into practice for nearly 30 years.
In 1954 a group of scientists invented the ‘maser’ (microwave amplification by stimulated emission of radiation).
The maser used microwaves. Research began into using light instead and the first device that produced laser light (light amplification by stimulated emission of radiation) was a ruby crystal, built in 1960 by physicist Theodore Harold Maiman, based on research by Charles Townes (who’d helped invent the maser) and Arthur Schawlow.
Gordon Gould had also been researching laser technology and claimed to have invented the laser three years before Maiman’s device. A big legal battle began, which Gould lost at first, but in 1977 he was granted several patents for his laser design. Still, Townes and Schawlow were awarded the Nobel Prize, which must have cheered them up a bit.
Today, lasers read CDs and DVDs, cut metal, take measurements, make holograms and are used in surgery.
Laser technology is being developed for use in warfare. The US and Israeli military Tactical High Energy Laser has shot down targets in tests. They’re not hand-held, Star Trek-style devices, though, more like tanks for shooting down incoming missiles.