As in biomedical science, pioneering industrial inventions have not been mothered by necessity. Rather, inventions for which there was no commercial use only later became the commercial airplanes, xerography and lasers on which modern society depends.
It was strange, in a way, because there were no ideas involved in the laser that weren't already known by somebody 25 years before lasers were discovered. The ideas were all there; just, nobody put it together.
I still try to make different types of lasers that other people don’t have.
In the late 1960s, red and the low green LEDs and the infrared semiconductor lasers had already been developed, but there was no prospect of practical blue light emitters, even in the '70s.
I said, suppose you take a light - I was thinking of just light bulbs because, in those days, lasers were not yet really there - and sent a light pulse between two masses. Then you do the same when there's a gravitational wave. Lo and behold, you see that the time it takes light to go from one mass to the other changes because of the wave.