This essay was originally published in One Hundred Reasons To Be A Scientist, a collection of essays published by ICTP in 2005. We’ll be periodically sharing some of the best essays from that book. Here’s the first one:
By Michael Berry
If you get your knowledge of science mainly from the TV, you might have the impression that it’s a weird activity, very far from what most people care about. But science isn’t remote at all: the world is connected in strange and wonderful ways. Think about this: many of you have a cd player. You can take it anywhere–on the beach, up a mountain, through the forests, in the deserts, at the North Pole, even–and listen to music reproduced almost perfectly. That wasn’t possible before in all of human history. In previous centuries, if you wanted to hear music, you had to go to live performances. But now we have this fantastic freedom that anyone, in any part of the world, can share the experience. In a way, it’s the ultimate democracy: making available to many what could previously be enjoyed only by a few. How has this come about? Strange as it seems: through a physicist’s dreaming.
Inside every CD player is a laser. Its light bounces off the bumps and pits on the disk, and electronics converts the signal into sound. The laser wasn’t discovered by accident. It was designed, by applying our understanding of waves and particles of light that comes directly from quantum physics, which gives our deepest understanding of the strange tiny world inside atoms and smaller. The laser works on a principle discovered by Einstein nearly a hundred years ago. It was pure theory–dreaming while you’re awake. He never dreamed that fifty years later other scientists would apply this principle to create bright pure light.