In 1964, physicist Richard Feynman delivered his “Messenger Lectures,” concerning the nature of the laws of physics, at Cornell University. He said, “I think I can safely say that nobody understands quantum mechanics.” That has certainly been true of me. I haven’t given up, though.
When I first studied quantum mechanics in college, I found myself utterly mystified. I learned that an electron can be in two places at once. I learned that an event can happen without a cause. I learned that you can measure the position of a subatomic particle, or its velocity, but never both.
How could such things be? When I was in school I never felt I understood this bizarre theory. Always I was telling myself that someday I really ought to sit down and figure it all out. But to tell the truth, I did not really have much time for such matters. I was too busy learning all those nuts and bolts.
For quantum mechanics is not just strange: it is also complicated. Throughout my studies I was barely keeping my head above water. Being a student is hard. There are so many new things to figure out all at once. Looking back on it now, I realize that I was learning a whole new language. It is a strange language, utterly alien, and it took a lot of getting used to. And why should this not be so? It is a language suited to the bizarre world of the quantum—not the everyday world of tables and chairs.
Eventually, things calmed down. I did reach some sort of accommodation with quantum mechanics. I learned to use its weird new language.
Skip forward many years. My attention turned to other things. But one day I noticed an old, familiar sensation—the sensation, nibbling at the back of my thoughts, that something was lacking. And one day I realized that I had never really comprehended this theory that I had been using with so little thought.
“Time to get going” I told myself.
What did I do? I read some books. I read some articles. But not that many books, and not that many articles. I talked to colleagues—but not that often. I took long walks and stewed things over. Mostly that’s what it was: thinking. I thought, and I thought, and I thought.
At the beginning I could not even say what I was thinking about. I would go back and look at the mathematics of quantum theory. I would work through things for myself. But even after I had done this I still felt mystified. The math wasn’t the point—the point was what it all meant. And why would my mind go blank whenever I tried to ask myself that question?
For months, I would feel that nothing was happening. But then I would cast my mind backwards and realize that my thinking was different. The questions I was asking myself had changed without my even being aware of the change. As a matter of fact, that was pretty much what it was like all along: I was hardly ever aware of what was going on. It felt like I was walking backwards; I wasn’t able to see where I was going until I got there. I never knew what was happening until it had finished happening.
Often, I was not even aware that I was thinking about it. I would be doing something else—washing the dishes, driving to the store—and without the slightest warning a thought concerning quantum mechanics would pop into my head. A pain in the neck? A delight? Yes—yes to both.
And then one day I had an epiphany. I saw what had been confusing me so thoroughly.
It was that I had developed in my mind two completely different spheres of thought. One was the strange language of quantum mechanics, which I had learned so many years ago. The other was the normal way of thinking that we all employ: the language of everyday life. And what I suddenly realized was that all along I had been thinking in both ways at once. I was moving smoothly from one sphere of thought to the other. And most important of all, this moving was unconscious.
If something is unconscious it just might cause you trouble. That, I suddenly saw, was what had been giving me so much grief for so very long.
This is not just my own personal history. For in truth I believe that it is the story of everyone who has encountered this bizarre world. The realm of the quantum is utterly unfamiliar, utterly strange and utterly incomprehensible. Nothing in it corresponds to everyday reality. And more than that: nothing in it can be comprehended in ordinary terms.
“How can an electron be in two places at once?” I had been asking for so many years. “How can something happen without a cause?” I have not answered these questions. But so what? At long last I have achieved what to me is a great victory. I have expressed to myself clearly what the mystery is.
And sometimes I wonder if it is a mystery. Perhaps it is just a fact. This is the way the world is. Do I like this new cosmos that we have stumbled into? Do I dislike it? Is it congenial to my thoughts, or utterly alien to them?
It makes no difference: this is the new world—get used to it.