The precursor to the laser was the maser. A maser is a laser that uses microwaves. Or you could say a laser is a maser that uses visible light. Either way, the maser came first.
The words are acronyms: Microwave (or Light) Amplification by Stimulated Emission of Radiation.
A fellow named Charles Townes had an idea for a maser one day back in 1951 and sketched it out to his colleague Arthur Schawlow. Both men were experimental physicists and three years later they produced a working maser.
But that’s not the story. The story is that when Townes went to his friend with the idea Schawlow said:
I love that answer.
It doesn’t sound like much, but it’s the perfect balance of enthusiasm and skepticism. By enthusiasm I mean the openness to something new. By skepticism I mean the lack of credulity.
Both are essential. You have to be receptive or you’ll miss out. But you also have to be critical. That way you won’t get fooled. Experimental physicists are more like engineers. They like to keep their feet on the ground. Two renowned theoretical physicists, Neils Bohr and I.I. Rabi, both told Townes his idea wouldn’t work. You never tell an engineer that something won’t work. These people spend their lives making things work!
Neils Bohr was one of the few physicists in the world that could go toe-to-toe with Albert Einstein. Their debates about quantum mechanics are famous in the scientific world. The theory of quantum mechanics is about 100 years old and one of the most significant results of that theory is, you guessed it, the laser.
Einstein’s paper “On the Quantum Theory of Radiation” introduced the concept of stimulated emission which is the basis of lasers. That was in 1917. In a weird twist, Einstein spent much of his professional life opposed to quantum mechanics, a field he helped create, and one in which Bohr holds an esteemed place. The Einstein-Bohr debates were mostly philosophical as quantum mechanics raises many interesting questions about reality and our attempts to perceive it.
Engineers and experimental physicists are feet-on-the-ground types, like I said, and don’t have much use for philosophy. Inventors always believe a solution is just around the corner, and that means they can’t be too particular about theories. They have to be flexible, and know that their working assumptions are just that. Philosophers and theoreticians spend a lot of time building their intellectual constructs and are quite invested in them. They can’t pull them apart so easily.
I don’t mean to disparage those with their heads in the clouds. There’s no laser without Einstein’s paper and Bohr’s theories. And those were built on theories from others like Max Planck and James Clerk Maxwell. Inventions don’t happen in a vacuum. There are a lot of people thinking and working at the same time. We love the idea of the lone genius but it is mostly a myth.
In fact, we are all inventors. We invent our own reality every day. And reality presents us with a lot of problems. That means we need solutions. And what do inventors say when considering solutions?
“OK, well, maybe . . .”