bag.
Okay. You’ve got two slits … one is closed, electrons or particles are zapping through the other one. What would you get on the screen behind the barrier?
With only one slit open?
Right.
Well … Gail hates puzzles. She always has. She considers puzzles as an invention of people who like to embarrass other people. If she senses the slightest hint of condescension in Jeremy’s mental tone, she’s going to punch him in the solar plexus. Well, I guess you get one line of electrons. A stripe of light or whatever.
Correct. Jeremy’s thought stream has taken on the slightly pedantic tone that he uses with his math students, but there is no condescension there. Only an eagerness to share an exciting concept. Gail does not hit him in the solar plexus.
Okay, continues Jeremy, now, what would you get with both slits open?
Two stripes of light … or electrons.
Jeremy sends the image of the Cheshire cat grinning. Uh-uh. Wrong. That’s what ordinary macro-universe common sense would dictate, but that proves not to be the case when you do the experiment. When you actually do it, with both slits open, you always get alternating bright and dark stripes on the screen.
Gail chews a thumbnail. Alternating bright and dark stripes … oh, I get it. She does, with only the briefest glimpse at the sentences and images Jeremy is framing for her. With both slits open, the electrons act like waves, not particles. The dark stripes are where the waves overlap and cancel each other out.
Got it, kiddo. A classic interference pattern.
But what’s the problem? You say that quantum mechanics predicts that little bits of matter and energy will act like both waves and particles. So they’re doing what’s predicted. Science is safe … right?
Bremen sends an image of a jack-in-the-box bobbing and nodding. Yeah … science is safe, but sanity is in real danger. The trick is … after all these years … that the very act of observing makes those particle/wave thingees collapse into one state or the other. We’ve tried incredibly complex experiments to “peek” at the electron during its transit … shutting one of the slits while the electron’s passing through the other one … we’ve tried everything. The electron … or photon, or whatever we use in the experiment … always seems to “know” whether the second slit is open or not. In a real sense the electrons behave precisely as if they not only know how many slits are open, but as if we’re watching them! Other experiments … Bell’s Inequality experiment, for instance … get the same reaction from separated particles flying apart from one another at the speed of light. One particle “knows” the state of its twin.
Gail sends the image of a row of question marks. Communication faster than the speed of light? she sends. That’s impossible. The particles couldn’t exchange any information if they’re flying apart at the speed of light. Nothing can travel faster than light … right?
Kee-rect, kiddo. Jeremy transmits the throbbing of his very real headache. And it’s been a headache for physicists for decades. Not only do these buggery little particles do the impossible … like know what their twin’s doing in the two-slit experiment and Bell’s experiment and others … but we still can’t get a peek at the real substance of the universe. The particle behind the curtain with its clothes off.
Gail tries to picture that. Cannot. The particle with its clothes off?
There’s no way we’ve devised, with all our hypertechnology and Nobel Prize winners, to sneak a peek at the real stuff of the universe when it’s wearing both aspects.
Both aspects? Gail’s mental tone is almost querulous. You mean both wave and particle?
Yeah.
But why is all this quantum junk important to understanding how the human mind … the personality … is like a superhologram?
Bremen nods. Part of him is thinking about Jacob Goldmann’s family in the death camps. Gail, the stuff Jacob is getting … the wave patterns that I’ve been translating through Fourier transforms and all the rest … they’re like reflections of the universe.
Gail takes a breath. Mirrors. You were talking about mirrors on Friday night. Mirrors of the … universe?
Yeah. The minds that Jacob’s been charting … those incredibly complex holographic structures, just graduate students’ minds … what they really shake down to is a sort of peek at the fractal structure of the universe. I mean, it’s like a two-slit experiment … no matter how cleverly we peek behind the curtain, there’s the same magic.
Gail nods. Waves or particles. Never both.
Right, kiddo. But we’re way beyond waves and particles here. The human mind seems to be collapsing probability structures in the macro as well as the micro.…
Which means what?
Bremen tries to find a way to limit the power of the concept to words. He can’t. It means … it means that people … us … you and I, everybody … we’re not only reflecting the universe, translating it from probability sets to reality sets, so to speak … we’re … my God, Gail, we’re creating it on a moment-to-moment, second-to-second basis.
Gail stares at him.
Bremen grabs her by the forearms, trying to get the terrible size and importance of the concept across to her through sheer pressure and force of will. We’re the observers, Gail. All of us. And without us … according to the math on my chalkboard at home … without us, the universe would be pure duality, infinite probability sets, infinite modalities.…
Chaos, sends Gail.
Yes. Right. Chaos. He collapses back in his seat. His shirt is plastered to his back and sides with sweat.
Gail sits in silence for a moment, digesting what Jeremy has said. The train clacks southward. For a moment there is darkness as they enter some short tunnel, then they are in the gray light again. Solipsism, she sends.
Hmmm? Jeremy has been lost in equations.
You and Jacob talked about solipsism. Why? Because this research suggests that man is, after all, the measure of all things? Gail never hesitates to use “man” to stand for “people” or “humankind.” She always says that she values clarity more than the feminist imperative.
Partially … Jeremy is thinking of Fourier transforms again, but more in an effort to hide something from Gail than to solve any problem in mathematics.
Why are you … who is this Everett person you’re thinking about? What does he have to do with that tree you’re trying to hide?
Jeremy sighs. You remember that Jacob and I were talking about some theoretical work that a guy named Hugh Everett did some thirty-five years ago?
Gail nods, sees Jeremy’s closed eyes, and sends an image of herself nodding.
Anyway, says Jeremy, Everett’s work … and the stuff done by Bryce DeWitt and others in more recent years … it’s weird stuff. It solves most of the apparent paradoxes of quantum mechanics, but it does it by getting into real deep water as far as theories go. And …
Impatient, Gail goes behind the words and the shifting math images to look at the heart of what Jeremy is trying to explain. “Parallel worlds!” She realizes that she has said this aloud, almost shouting it. A man in the seat across the aisle glances over, then returns to his newspaper. Parallel worlds, she sends
