A new book by physicist Vlatko Vedral, Decoding Reality: The Universe as Quantum Information, gives me new insights about reality.We know the world — or, put more expansively, the universe — is made up of matter. Einstein's E=mc2 showed that matter is a form of energy, so matter and energy are the same thing.
Meanwhile, other physicists such as Niels Bohr were showing that the basic particles of matter and energy — say, electrons for matter, photons for energy — behave in ways that defy common sense. Thus was born the science of quantum physics.
Quantum physics — a.k.a. quantum mechanics — shows how the tiny particles and packets of energy that make up everything we know do strange tricks like being in two places at once. You can pass a photon of light through a "beam splitter" and find that half the time it actually does pass straight through, and half the time it gets reflected onto a different path. Which path it takes is truly random.
Actually, it takes both paths at the same time. Only when we measure or observe the photon's behavior do we lock it into once choice or the other.
Before that observation takes place, you could say (but only very, very loosely) that there are two-photons-in-one. Better put, "they" share "mutual information," which means that our observation of "their" behavior at the beam splitter results in that behavior becoming either-or, not both-and, and it only thus becomes consistent with our common sense and logic. (But which choice the observed photon actually uses is a coin flip. We can never, under any circumstances, predict it. We can never force one outcome to occur over the other.)
Mutual information is known to us in our everyday lives. For instance, if two people are in a bar deciding on what drink to order, and if one says to the other, "I'll have what you're having," then an observer would say there exists mutual information. Knowing what Imbiber A orders tells us what Imbiber B is going to have.
Vlatko Vedral talks a lot about mutual information, which is what typically occurs in the world of "quantum information."
Quantum information is an enlargement of "information theory." The latter began in the middle of the 20th century when Bell Labs researcher Claude Shannon was trying to figure out how best to send information down a noisy telephone line. What is information, actually? asked Shannon. It's anything that, by surprising us in some way, conveys a state of affairs we weren't expecting. "Congratulations, you've won the lottery!" contains a huge amount of information. Static on a telephone line contains zero information (especially in the old, pre-digital days when static was always present on phone lines).
We know that information is, on a computer, contained in bits. Each bit is either a zero or a one. In quantum information, quantum bits or "qubits" are used instead of regular bits. A qubit can in effect be zero and one at the same time. For example, it can be "1/3 zero" and "2/3 one." That is, when we actually observe it and lock it into one definite value or the other, 0 or 1, the chance that it will wind up being zero is 1-in-3, while the chance that it will wind up being one is 2-in-3.
As long as the probability that it's zero and the probability that it's one — after being observed by us, that is — no laws of nature are being violated at all.
So what? Well, the answer to that question has practical dimensions and philosophical ones. I'll let Mr. Vedral tell you about some of the practical ones in his video discussion of his book:
The philosophical dimensions are the ones that interest me. Vedral hints at some of them toward the end of his video.
He shows, mainly in the last part of his book, that there's good reason to believe that information — of the quantum variety — is the stuff of all reality. Matter and energy very likely emerge from qubits, and qubits are repositories of mutual information which — only when they are measured by some observer such as us, using a beam splitter — behave themselves like regular bits, 0's or 1's, of information.
But where do the qubits come from? Here's where things get very interesting. Quantum information doesn't have to have a source or cause of existence.
If we ignore for a moment that qubits are probabilistic and think of them as if they were regular bits, we know that regular bits represent numbers (out of which computers construct other sorts of data). Numbers can, like qubits, be said to be primary to all our reality. That's why quantum theory and Einstein's theory of relativity can be collapsed into a set of formulas like E=mc2. Formulas are just ways of manipulating numbers.
So to answer the question of where do number-representing qubits come from, we can ask where numbers themselves come from. Vedral shows (borrowing from computer pioneer John von Neumann) that numbers come from ... nothing whatsoever!
The behavior of numbers can be shown to depend on "set theory." "Sets" are, basically, collections of numbers. {1,2} is a set of numbers that is, in turn, a subset of {1,2,3}. {1} is a subset of {1,2}. Does {1} have any subset? Yes: the "empty" set.
Von Neumann showed that the empty set contains itself ... meaning that the contained empty set has one element. Thus does the number 1 emerge from the number 0!
The contained empty set also contains itself. Thus does the number 2 emerge from the number 1!
And so on. All the numbers that exist emerge from an empty set that represents 0, or nothingness!
If qubits equate to numbers, then all quantum information emerges from nothingness. If all the world's a body of quantum information, then the whole universe emerges from (as I'll call it) "zerohood."
Furthermore, each number in the sequence of emergence-from-zerohood depends on all the earlier numbers in the sequence. They share mutual information, just as Imbiber B who says "I'll have what you're having" depends on Imbiber A.
Our act of measurement or observation of quantum behavior is like when we take a photo of kids jumping on a trampoline:
It looks like they're motionless, but of course they're not! Likewise, when we "capture" a quantum event by observing it, it turns into a randomly chosen, but definite, outcome. We lose, meanwhile, the "mutual" information whenever a qubit of information is turned by our observing it into a hard-and-fast bit.
For example, when we observe the position of an electron, we thereby lose any ability to learn its speed, direction of motion, and momentum. An electron's position and its velocity are related by virtue of being mutual information.
Can you tell, in the photo above, whether the kids are on the way up or on the way down?
We could say that the kids' direction is basically, as far as we are concened, a coin flip: we might as well flip an ordinary coin to decide which direction they are going in.
But at the same time, we are aware that what direction the kids were actually going in when the photo was taken is deterministic, not random. If we knew what forces were acting on them just prior to the taking of the photo, we could say for sure what direction they were moving in.
Not so with quantum behavior. There is no way to be sure, for example, which direction of motion a beam splitter will yield when a photon is sent into it: will it pass straight through, or will it be reflected?
Yet, says Vedral, quantum behavior is (according to the equations of quantum theory) just as deterministic as the mechanics of jumping on a trampoline! It's just our act of observing quantum behavior that turns it — seemingly — random.
So there's a mysterious interplay between deterministic quantum information and any and all acts of observation and measurement of that information, which makes the quantum information seem, in some of its aspects, random.
From the point of view of its randomness, quantum information is truly random. It's not like a physical coin flip, which seems random in its result but is actually subject to the laws of classical physics, à la Isaac Newton. If we had enough information about (among other things) the force applied to it by a thumbnail when it is flipped into the air, we would be able to predict with perfect accuracy whether it is going to come down heads or tails.
Not so with "quantum coin flips." No amount of prior knowloedge could tell us whether a photon will pass through a beam splitter or be reflected.
That means that we have no business saying that the outcome of a "quantum coin flip" has a cause! In fact, it has no cause whatsoever.
But everything we observe in the universe is, ultimately, a series of quantum coin flips!
That suggests that the observable universe is, at base, uncaused. As it emerges from "zerohood," it is fundamentally without cause.
This is what really interests me.
We see a world in which, for most practical purposes, everything that happens — every "event" — has a cause. Newton's laws of mechanics and of gravity seem to tell us everything we need to know ...
... except that they don't. Einstein proved that, and then the theorists of quantum physics came along and confounded even Einstein, who said "God does not play dice with the universe."
Well, if there is a God, He clearly does play dice — specifically, the fact is that quantum coin flips are behind everything we see. Before there is matter and energy, the stuff of reality is quantum information.
To me that suggests that we, as observable beings of and in the universe, are radically free. At root we are, by the ceaseless acts of observation that ascertain our very being, a coterie of random, quantum coin flips. At root, we are uncaused.
By the logic that applies to quantum phenomena — see above — we are also, in addition to being random and uncaused, deterministic in the very fabric of our being. We are both random and deterministic. We have free will, by virtue of our essential "quantumness," but we are also swept along in the Newtonian, deterministic flow of all the physical events in the universe.
Wrap your mind around that, if you can!
* * *
This view of reality both giveth and taketh away.
It giveth us the ability to say something intelligent in favor of the gut feeling we all have of possessing free will. Philosophers have long debated free will vs. determinism as if the two were mutually exclusive — as our ordinary, everyday logic would seem to dictate. But if Vedral is right about reality being at base quantum, then ordinary logic need not apply.
We can be wholly deterministic beings like the planets in their orbits, and yet we can still have free will!
Of course, common sense still tells us that that conclusion has to be bogus. Seemingly, we have to be, at base, either free-willed or deterministic. Yet Vedral's worldview says no.
There's still a fundamental mystery here, of course. But there's just as much mystery about all things quantum. Richard Feynman, winner of the 1965 Nobel Prize in Physics, once said, "I think I can safely say that nobody understands quantum mechanics."
This view of reality also taketh away — see above — our justification for imagining that the universe and all things in it have a cause.
We who believe in God are accustomed to thinking that it must be true that, however metaphorical we may take chapter one of the biblical Book of Genesis to be, God caused the universe to come into existence. The view of reality expounded in Vedral's book says no to that.
If we want to trace reality back to God, says Vedral, we must instead do so apophatically. Wikipedia says in this article:
Apophatic theology — also known as Negative theology or Via Negativa (Latin for "Negative Way") — is a theology that attempts to describe God, the Divine Good, by negation, to speak only in terms of what may not be said about the perfect goodness that is God.For example:
... one should not say that God is wise since that word arrogantly implies we know what "wisdom" means on a divine scale, whereas we only know what wisdom is believed to mean in a confined cultural context.One can accordingly say only that God is not ignorant.
Similarly odd to our way of thinking is the idea that God does not cause the universe to exist. Yet such apophatic thinking is precisely what gives us any basis at all for claiming free will! If God causes the universe to exist, then there is no entry point for "zerohood." If there is no entry point for zerohood, Vedral's whole view of reality collapses — as does any quantum basis for claiming free will.
That there is, at the most fundamental level, a break in the chain of causation where "zerohood" asserts itself is, to me, a hugely liberating realization. God tolerates a break in the (ordinarily) totally caused chain of events. God, in fact, insists on it!
* * *
My assumption, deep down, usually is that everything is chained inexorably to everything — as would be the case if all the cars on the road were somehow chained to one another, so that if I run amuck, gun my engine, and run myself into a brick wall, they'll all crash too.
But, no. The world is not cars that by "tight causality" are chained inexorably to one another, such that my errors of comission, or merely of omission, will cause untold driver deaths. Rather, the world is — fundamentally is — a set of bumper cars in an amusement park ride.
Ever ride bumper cars? They have a mind of their own. Try as you might to steer them the way you intend, they insist on veering off on their own tangent and hitting — or missing — whatever might come in their way.
If Vedral's view of reality is right, we live in a "bumper cars world." There is so much stuff that happens that is without any cause whatever, that wrecks on the highway are inevitable. They can't be headed off by everyone being "good citizens of the road." They just can't. They're built into the fabric of reality.
Let me try to put it in a more concrete way. In my usual, tightly causal view of reality, I normally am burdened with the assumption that "bad" stuff like, say, homosexuality can be "fought against" successfully. Hence, someone who is homosexual obviously is or has been the victim of something or someone whose influence, way back during the person's formative years, possibly, has "made" that person what he or she is today.
What was it that did that terrible thing, that had that awful influence over the fate of a fellow human being? Possibly it was a gay teacher in elementary school. Possibly it was a character on a kids' TV show. Who knows exactly what it was? But in a tightly causal view of reality, it is something that can be identified, fought against, and rooted out.
By the same token, in a tightly causal view of reality, I personally have a responsibility to do whatever is necessary, on my little part, to help wage a war against all sorts of "bad" stuff like homosexuality. I ought accordingly to support, say, counseling programs that (claim to) turn gays into straights, or ballot initiatives that (hope to) make gay marriage illegal, or campaigns to put the kibosh on, for example, TV Teletubbies who are "obviously gay."
But in a "bumper cars" view of reality, nothing "causes" all the "bad stuff" in the world. Cars just veer into one another, willy-nilly, and I'm personally off the hook if "bad stuff" like homosexuality happens in this, our mutual "society of the road," while I'm behind the wheel of a vehicle.
In fact, "bad stuff," like someone being attracted sexually to his or her own gender, is not put in train by any event, past or present, which has "made" him or her gay. The bumper sticker is right: it is really true — basically, fundamentally — that "shit happens." There is no devil luring us inexorably, by some tightly coupled chain of adverse causality, to wrack and ruin.
If I thereby let the world off the hook for all the wrecks that I personally think I see on the highway — gay sexual orientation being a metaphorical stand-in here for a whole lot of stuff I normally try to steer my own personal bumper car away from, in hopes of making this a "better world" — then I have to let myself off the hook, too. I am in no way responsible for all the shit that happens in the world.
That's why it is a hugely liberating realization that Vedral's book makes me aware of: the fact that there is, at the bottommost level of that-which-is, a fundamental break in the chain of stuff-causing-other-stuff. There is, in the way that I put it earlier, a place at the very bottom of the deck of reality where causal "zerohood" asserts itself, and cards, good or bad, can be dealt completely at random.
That fact alone lets me personally off the hook for all the shit that happens in the world. And then that hugely liberating fact goes on to pay wonderful dividends: it lets me treat myself and everyone else not as bundles of effects of inexorable causes that make us "bad" or "good" without recourse, but as persons who are worthy of respect regardless.
