I often wondered who and what made it possible for my alcoholic buddy to wield such a dangerous tool. They’ve been around in one form or another for a while, of course — the invention of lasers writ large can be traced all the way back to 1900, which was when famed German physicist Max Planck published a paper surmising that energy is made of individual units, which he called quanta. His theory would later inspire Albert Einstein, who became the first person to realize that light is made up of photons in 1905. Using this knowledge, Einstein proposed a theory called stimulated emission, a process by which electrons (previously known as the aforementioned quanta) can be stimulated to emanate light of a particular wavelength. This is the process that would eventually make lasers possible.

Forty years later, Columbia University professor Charles Townes conceptualized a device that would come to be known as a maser (microwave amplification by stimulated emission of radiation) while sitting on a park bench in Washington. Based on Einstein’s stimulated emission theory, the device was able to amplify and even generate electromagnetic waves. A few years later, in 1957, Columbia University graduate student Gordon Gould scribbled the acronym LASER (light amplification by stimulated emission of radiation) and described the elements needed for constructing one in his notebook, which would eventually become the focus of a 30-year court battle for the patent rights to the device.