16 A New Universe
It was many years ago that I first encountered the Great Predictor.
I was thrilled to meet him. I’d been looking forward to the encounter for years. The Predictor was famous—world famous. He was legendary for the number of his predictions, and for their amazing accuracy. Many people had relied on those predictions, and always with profit.
What intrigued me the most, however, was how bizarre were some of his predictions. “Tomorrow you will be in two places at once” was one. “On Wednesday an event will occur for which there is no cause” was another.
How could such things be? I was captivated by the strangeness of these prognostications. Could such weird things really come to pass? That’s why I had been so anxious to meet the Predictor. For years I had looked forward to finally getting to know him.
At long last I was getting my wish. I was twenty years old, and I was thrilled. I was sitting in a classroom, in college, on the first day of a course called Introduction to Quantum Mechanics.
That was many long years ago. And throughout my career I have maintained my early fascination with quantum mechanics. Somehow, though, I never felt that I really understood the theory. It always sat lodged in the back of my mind—enigmatic, mysterious, enticing. Over and over again, I found myself thinking that someday I really ought to go back and figure it all out, and finally put all those early juvenile confusions to rest.
Part of that project was an effort to understand Bell’s Theorem. To be honest I found myself dreading getting to work on that particular topic. While I had never felt comfortable with quantum mechanics in general, Bell’s Theorem was a topic that I felt positively unnerved by. Over and over again I had tried to master it, and over and over again I had failed.
Eventually I did come to some sort of understanding of Bell’s work. I recall feeling pretty pleased with things … until the fateful day when I looked at my reflection in the mirror—and this is literally true—and I spoke aloud. “Greenstein,” I said to my reflection “you were just kidding yourself, weren’t you? You never really understood Bell’s Theorem at all, did you?”
“Time to get going,” I told my reflection.
And I did.
What did I do? I read some books. I read some scientific articles. I have already mentioned one: there were others. But, truth to say, 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. It went on for several years.
What was I thinking about? At the beginning I could not even say. I would go back and look at the proof of Bell’s Theorem. I would work through the mathematics for myself—remarkably, the actual calculations involved are not so very hard, now that Bell has shown the way. But even after I had done this I still felt mystified. The math wasn’t the point—the point was what it all meant. I knew damn well that Bell’s discovery was important—everybody else was going around saying that it was important, and it certainly felt important to me. But why? What was his theorem telling us? And why would my mind go blank whenever I tried to think about it?
That last question was a signal. By now I know myself well enough to realize that if I find it hard to even think about something, it is a signal that there is some enormous gap in my understanding. Somewhere, something was missing from my thoughts. But what?
For months it would feel that nothing was happening—but then one day I would cast my mind backward and realize that my thinking about Bell’s Theorem was different. In the intervening months my thinking 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 backward—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 the issue. 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.
Writing was helpful. It always clarifies my thoughts to get something down in plain English. That’s why I wrote this book: to clarify my thoughts. Of course I couldn’t write the book until I had cleared up my thinking—and I couldn’t clear up my thinking without writing the book. So it was a back-and-forth process.
Looking back on it all, I now feel that what I was doing was facing for the first time how utterly strange quantum theory is. A student learning quantum theory must learn a whole new way of doing things. The way involves mathematics that seems to have nothing to do with the subject at hand. An example is those matrices of chapter 6—nowhere within them do you find the slightest image of a spinning object. And the same is true of all the rest of the theory.
And then one day I had an epiphany.
The amazing thing about that epiphany is that it happened in a flash—at a precise instant of time. As a matter of fact, so momentous was that instant that I took note of it. Even now a small sign sits above my desk:
The Epiphany
11 AM, Friday July 10, 2015
Another bright and sunny day
(Big thunderstorm last night)
I don’t want to give the wrong impression. I don’t want to imply that in order to understand something hard, all you have to do is sit around and wait for inspiration to hit. My epiphany would never have come had I not spent all those years of work stewing things over. The epiphany was just the final step.
Nevertheless, it was a climactic moment. It felt as if I had been wandering around for years through a darkened house, and that I had ultimately found myself in a pitch-black room, a room I had never been in before—and suddenly the lights turned on.
Here is what I saw.
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 new language of quantum mechanics that I had learned so many years ago. The other was the normal way of thinking that we all employ: the automobile is right there and it is going that way at such-and-such a speed; the golf ball is spinning so fast in this direction. And what I suddenly realized was that all along I have been thinking in both ways at once. I was moving seamlessly and smoothly from one sphere of thought to the other. And most important of all: this moving from one to the other 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.
Indeed, I had been actively preventing myself from realizing how utterly incompatible those two ways of thinking are. This incompatibility is the very essence of this book. It is the essence of Bell’s Theorem. What Bell’s Theorem proves is that quantum mechanics is not a local hidden-variable theory—and that’s just a fancy way to say that it is not a theory of normal reality. And the experiments testing Bell’s Theorem—metaphysical experiments—are telling us that the hypothesis of normal reality is untenable. There ain’t no such thing.
This “doublethink” had been infecting all my thinking over the years. Indeed, it has infected this very book. In the first chapter I wrote of my youthful amazement that something could be in two places at once. Indeed, I was frustrated that the Great Predictor refused to tell me how this could be. Later on, in chapter 6, I had advanced in my thinking somewhat, and wrote that the problem lay with the language the Great Predictor spoke. It was, I wrote, a strangely impoverished language, and my poor Predictor was simply tongue-tied: his language was incapable of expressing certain things. But now I suddenly realize that the truth is far stranger than that: it is that my very question was misguided. “How can a thing be in two places at once?” I had asked—but buried within that question is an assumption, the assumption that a thing can be in one place at once. That is an example of doublethink, of importing into the world of quantum mechanics our normal conception of reality—for the location of an object is a hidden variable, a property of the object … and the new science of experimental metaphysics has taught us that hidden variables do not exist.
Another example of how I had been unconsciously moving between these two spheres: radioactive decay. In chapter 2 I discussed how one nucleus would decay rapidly while another would decay more slowly. What enables one nucleus to survive for longer than the other? The Great Predictor refused to say. I was frustrated by this refusal, but now I see that contained within my frustration was another assumption: the assumption that there is a reason—some property that distinguishes the short-lived nucleus from the long-lived one. And now I realize that reasons are hidden variables … and hidden variables do not exist.
I would not be wasting the reader’s time on my own personal history had I not felt that it has a wider moral. For in truth I believe that what I have been recounting in this book is not just my own story: I believe it is every scientist’s story. Einstein believed utterly in a real physical situation, and he fought for that view to the end of his life. Bell did too: “Everything has definite properties,”1 he would often say. And perhaps you recall my earlier quote from the quantum physicist E. T. Jaynes, who termed the view that there was no such reality “a violent irrationality” (chapter 13) So I am not ashamed of thinking according to our normal conception of reality. That is how these people thought, and if it was good enough for them it is good enough for me.
As a matter of fact, I believe that the real point goes beyond what I myself think, or what this person or that person thinks. I believe that in truth we cannot help thinking that way. That is the only way we know how to think. It is how our minds work.
And it is how science works—all of science: biology and geology and chemistry and, indeed, every facet of physics other than quantum mechanics. I want to emphasize this. Never before have we encountered a situation like the one that experimental metaphysics has forced on us. Relativity, the space program, the genomic revolution, artificial intelligence—none of these have required so great a shift in our thinking. Earlier in my career I worked on neutron stars: monstrously dense, exotic in composition, ferociously magnetic … but each one of which sits in a perfectly definite place and spins at a perfectly definite rate in a perfectly definite direction. A geologist might be concerned with the motion of magma hundreds of miles beneath her feet—a magma that neither she nor anybody else has ever seen … but nevertheless a magma that has a perfectly definite temperature and pressure. A biologist might study the evolution of creatures now extinct: creatures that no one has ever seen … but creatures whose size and shape and mating habits most definitely existed.
No matter how exotic and unfamiliar the objects that scientists study, until now all of them have conformed to our normal conception of reality. There is only one small problem: the new science of experimental metaphysics has shown that within the microworld this normal conception of reality does not apply.
“Shut up and calculate.” That is the way people often refer to the standard approach to quantum mechanics. “Don’t waste time thinking about all this stuff” might be a good translation. “Just get going and do the calculations.” I used to think the phrase was pejorative. Now I am not so sure. Maybe it is not pejorative. Maybe it is great wisdom.
The astute reader will have noticed that I have not solved the mystery of quantum theory. I have not explained how things can have no properties. I have not explained how nonlocality can bind the universe together. No matter: I am content to rest. At long last, I have achieved what to me is a great victory. I have expressed to myself clearly what the mystery is.
Because in truth 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? Well, I guess I would say that it makes no difference: this is the new world—get used to it.
Listen to the words of Richard Feynman:
We always have had a great deal of difficulty understanding the world view that quantum mechanics represents. At least I do, because I’m an old enough man that I haven’t got to the point that this stuff is obvious to me. Okay, I still get nervous with it. … You know how it always is, every new idea, it takes a generation or two until it becomes obvious that there’s no real problem. It has not yet become obvious to me that there’s no real problem. I cannot define the real problem, therefore I suspect there’s no real problem, but I’m not sure there’s no real problem.2
Not long ago I had a dream. In that dream I was on a powerboat far out to sea. The engine was off. No breeze blew: we drifted aimlessly. An immense silence reigned. The sky was gray and vague, the horizon obscured by haze. Nothing was happening. Everything was listless.
At long last I roused myself to wonder where we were. Reaching down into the water I gave a sideways paddle. Slowly the boat spun about—and suddenly there came into view a stone jetty. It was a mere few feet away! While I had been listlessly waiting, the boat had drifted right up against the shore.
The boulders of the jetty were hard and clear, utterly solid and picked out in vivid relief. Looking upward I saw that the haze had lifted, and that the sky was now a crystalline blue. Gazing down into the water I saw that it too was clear and lovely. I could see the bottom. Could I reach it and so give us a push? Leaning over, I found the water just slightly too deep. Or could I reach the jetty, and push off against it? Leaning sideways, I found it just slightly too far away.
Not a problem—we had an engine. I reached for the starter switch.
There was a mirror. I looked at my reflection in it. “Time to get going” I told my reflection.
And I did. And we are.
Notes
The epigraph of this book is a quotation from a lecture by Richard Feynman. Actually, I took that quote out of context. Here is a bit more of it:
I think I can safely say that nobody understands quantum mechanics. So do not take the lecture too seriously, feeling that you really have to understand in terms of some model what I am going to describe, but just relax and enjoy it. I am going to tell you what nature behaves like. If you will simply admit that maybe she does behave like this, you will find her a delightful, entrancing thing.1
Note