Quantum Mechanics and The God of Abraham, Isaac, and Yoda

Ben F. checks in with a third installment in his BCC guest series on faith and physics. (Read his earlier posts here and here.)

YodaEveryone knows that Star Wars is nothing more than a (brilliant) allegory of the Gospel and the Restoration. Luke is Joseph Smith, Yoda is Peter, the Force is obviously the priesthood, and so on. With this understanding, I learned a lot as a child about how spiritual things work, including the important fact that you can use the priesthood to control things with just your mind.

Naturally, this is also how God does his work. Miracles, answers to prayers, revelations, and all other heavenly manifestations are instantaneously and immaterially transmitted from the mind of God directly to his children in need. God, bodily present at some physical location, wills something to occur, and millions of lightyears away, a mountain moves, or a voice is heard, or a prayer is answered. This is what I learned from Star Wars.

I should be careful not to poke too much fun at either Star Wars or God’s miracles, since both are actually quite important to me, but the tiniest bit of creativity is enough to realize that there are much richer and more impressive ways that God could choose to bring about miraculous occurrences other than just thinking something in his mind.

He can use his divine foresight to set natural processes in motion millions of years in advance of a desired outcome, or he can utilize the complex sociological forces of an interconnected world to cause one person to be the answer to another’s prayer, or maybe he just organized such a perfect and efficient system that it takes care of itself without any further interference from him. Surely these possibilities are more in line with rational thought. And yet, part of me still clings to the idea that God can control things with his mind and nothing more, that he actually does use the Force to accomplish his divine purposes. At the very least, I want to believe.

Fortunately for me, quantum mechanics gives us at least a glimmer of hope that Jedi mind tricks could be part of our divine potential. I am, of course, referring to quantum entanglement, one of the weirdest and coolest consequences of quantum mechanics. Forgive me if this is already common knowledge for everyone, but I will give a very brief explanation of quantum entanglement.

In classical mechanics, i.e. the Newtonian take on the laws of nature, the condition or state of an object is described most succinctly by specifying its precise position and momentum. If these quantities are known, then the future behavior of the object can in principle be predicted exactly. Of course, this is not actually possible, since classical mechanics succeeds only in approximating what actually happens as governed by quantum mechanics. From quantum mechanics, we know that the position and momentum of an object can never be simultaneously specified with perfect precision—this is the famous Heisenberg uncertainty principle—so the state of that object is instead described by a mathematical entity known as a wave function, which is used to determine the probability that the object has a certain position, momentum, or other physical quantity of interest. If you were to complain that quantum mechanics is not a very good theory since it cannot even determine the exact position and momentum of the objects it is trying to describe, then you would be missing the point. It’s not that we just don’t know how to measure the position and the momentum; it’s that a quantum mechanical object (i.e., everything) simply does not have a definite position and momentum.

One clarification is in order. Something weird happens when you try to measure some property (position, momentum, energy, etc) of a quantum object—when it interacts with your measuring device, it nearly instantaneously “chooses” a value of the property of interest according to the probability dictated by the original wave function. This is somewhat inaccurately called “wave function collapse,” since the wave function, which originally may have allowed a wide range of different values of the property, has now collapsed around a single value (or at least a very narrow distribution of values).

Getting back to the point, quantum entanglement is when two or more quantum objects interact in such a way that they can no longer be described by individual wave functions, rather they must be described by a single joint wave function containing all possible information about all of them together. In a sense, the interaction that gives rise to entanglement causes the previously distinct objects to meld into a single entity.

As a simple example, consider two photons, one with “spin up” and the other with “spin down.” Here, spin refers to a quantum mechanical property related to the polarization of the light waves. Let’s suppose they are made to interact such that their spins become entangled. Now, instead of each photon having a distinct spin, both photons are simultaneously both spin up and spin down. More precisely, they are both described by a single wave function which is the superposition of the two original spin states. Say we allow the two photons, still entangled, to travel in opposite directions for a long time, maybe two years (but it could be as long as you want). We very carefully cleared paths through space for them so that nothing would disturb them and thereby destroy the entanglement. After two years, they are four lightyears apart from each other—roughly the distance from Earth to the nearest star, Proxima Centauri. Now for the real kicker: if you grab one of the photons and measure its spin, then the wave function collapses and the photon is forced to pick a spin state, either up or down— let’s say up. Then, at that very same moment, the other photon four lightyears away is instantaneously forced to become spin down. This is truly an instantaneous process, and it happens without any medium connecting the two photons. There you have it—an influence exerted instantaneously and immaterially across vast regions of space. It’s just like the Force, and just like how I used to imagine God works.

This sounds almost too good to be true. With instantaneous communication across arbitrarily large separations and the ability to transmit a force or influence without any medium, the possibilities are endless. Alas, it is too good to be true. Here’s the catch: when you measure the spin of the first photon, you have no way of controlling or even knowing whether or not it will turn out to be spin up or spin down—both outcomes are equally probable. Therefore, you cannot control what the result on the other end will be, so you have no way of using this procedure as a means of communication. Einstein’s sacrosanct law of special relativity that no communication can travel faster than light remains intact, and we remain without a way to control events from afar with an instantaneous and immaterial force. Quantum mechanics gets us so close but still leaves us so far away.

Of course, we reach this conclusion only if we accept that quantum mechanics is the whole story. Einstein himself was actually the most famous doubter of quantum mechanics during its discovery and development, and he spent much of his life searching (fruitlessly) for so-called “hidden variables” that would show quantum mechanics to be an incomplete picture of reality. Today, however, there is almost universal agreement that Einstein was wrong about the hidden variables and we must simply accept the startling ambiguities inherent in quantum mechanics. Every now and then an interesting paper contesting this will pop up, but very little serious research is being conducted in this field. On the other hand, quantum mechanics (and the Standard Model it produced) most certainly is not the whole picture, since it fails to successfully incorporate gravity into its framework, but the ways in which it is incomplete do not seem to be especially promising for the possibility of getting our Jedi mind tricks to work.

So why did I waste your time with all of this stuff about quantum entanglement if it doesn’t even work? Well, quantum entanglement is not completely useless—after all, it forms the basis for quantum computing, which will almost certainly revolutionize the world at some point—and moreover, entanglement provides insight into the bizarre nonlocality and striking instantaneity permitted by quantum mechanics that may very well end up being useful for understanding how God does his work. And more generally, quantum entanglement is yet another beautiful demonstration of how science carries with it a stunning variety of phenomena that give us meaningful or at least entertaining new ways to revisit our religious beliefs and traditions, even if the loose ends are not coming together quite yet. There are many great and important things yet to be revealed…

Comments

  1. Quantum entanglement is awesome and I suspect a very interesting area of research ahead. I just hope I live to see quantum teleportation do something cool. (Hey, maybe God is more clever then we thought… is that is possible)

  2. The last post in this series asked how God could predate our universe, and yet now be a part of it. Multiverse cosmology offered a promising avenue for speculative solutions, with the minor caveat that it does not appear to allow interaction between our universe and an external agent. This post asks how God can exert “action at a distance” in a universe with a finite speed of light. Quantum entanglement offers a tantalizing hint at a possible solution, except for the pesky fact that it does not allow for superluminal communication, i.e. the thing we are trying to explain.

    It seems like we begin dissatisfied with the age-old “God is not subject to physical law” or the newer “God acts according to laws we cannot comprehend”, and so we appeal instead to weirdness of modern physics, where we find successful models that defy our everyday experience. When those theories still don’t allow for the phenomena we hope to explain, we are consoled by the idea that fundamental physical law, in its best modern interpretation, includes wackiness that we cannot comprehend, so the answers to great mysteries of God could still be lurking in there somewhere.

    So have we replaced the old approach with – itself, but with some decorative equations in the general vicinity, or is this really a new approach that is sound but just hasn’t yielded much fruit yet? I hope it’s the latter, because I don’t know what else to think about during the temple movie…

  3. That’s a fantastic question, Aaron. Analogously, one could ask whether research (in any field) is less wrong than intuition when both turn out to be wrong. Societally, we’ve accepted a model of what counts for truth in science. We like to tell ourselves that we’ve chosen the only reasonable methodology, but we wave our hands over what constitutes reasonableness in the first place. No matter what, we see through a glass, darkly.

  4. I take the standard for truth in science as both clear and essential in distinguishing science from other fields such as philosophy and religion. According to that standard, a theory or model is accepted (“truth” is probably not the right word) if (1) it accurately describes phenomena that can be observed, (2) it succeeds at making predictions that can be tested experimentally, and (3) it is reproducible in the sense that anyone else can replicate the experiment and get the same result. I don’t think agreeing upon that standard constitutes handwaving. The limitations and handwaving come in when we can’t apply the standard fully, or the best models available don’t account for the new phenomenon we’d like to explain, but we still want to appeal to them anyway. That’s not necessarily an unreasonable approach – it’s using what you have to direct further exploration in the most promising directions. There’s just no guarantee it will ever actually get you anywhere. Some partial success along the way might be enough to say that the application of science actually constitutes a new approach to these big questions.

  5. Maybe I’m looking at this the wrong way. Even if QM doesn’t answer the fundamental question (i.e. How could He possibly do that?), it still provides us something very new. A century ago, we would have to say that, for example, all objective experience indicates that one thing cannot be in two places at once. Now, however, we have physical observation indicating that in a sense it can be (insert appropriate caveats here). This offers hope that religious phenomena that used to be in clear contradiction with scientific “knowledge” might not always remain so.

  6. Aaron, and yet those criteria you laid out are, in a real sense, arbitrary. They have purpose, but only because we value what they tend to do, and there’s no reason to suspect that our current valuation is, in any way, inherent in the universe. It may help us delineate what we call “science” just as a range of wavelengths can help us delineate what we call “infared” from anything else, but why pretend that “science” or “infared” is categorically different from “intuition” or “red” or that it has any uniquely inherent value? Science, for example, has never done well with the Obi-Wan principle (truth depends on your point of you).

  7. Actually, the Obi-Wan principle as you stated it is the entire basis of special relativity…

    The inherent value of science is that you can predict the outcome of an experiment, like how fast the ball you just dropped will be moving when it hits the ground, and get it precisely right every time. It cannot claim the prove that the theory of gravity is “true”, only that it provides an accurate description of interactions between objects that have mass (Maybe that is your point?). We could always be getting it right for the wrong reason, and science can never claim to prove whether that is the case.

  8. Ha! That should read “point of view” but okay, I suppose it fits into the multiverse theory as written.

    Yes, that is part of my point. Another part is that science only lets us predict certain things (velocity, in your example) and so we privilige those things that can be quantified over other things (e.g., *should* I drop the ball, for example). Don’t get me wrong, I love science and quantifying and I see the use in delineating by labels, such as “science,” but the arbitrary associated assignment of value troubles me. There’s little basis for saying Newtonian physics are less wrong than Aristolean physics except by invoking some non-universal culturally derived metric. We so often speak as if there were no other “reasonable” way to think about the universe besides the modern incarnation of science.

  9. Thanks for the comments, I’ve enjoyed reading them. Aaron, I think you nailed it in #7. Far from imposing more stringent constraints on any attempts at rational religion, recent advances in science actually seem to have opened up broad new avenues for possible reconciliation. That’s one of the messages I hope to be communicating through these posts. As to your point, Brian, I can certainly acknowledge that society is better off for having other worldviews besides that offered by science, but I’m afraid I still need to shed some of that pesky scientist’s hubris before I can agree that the scientific method does not have some unique place among all other methodologies. I hate to be a Zoramite, but I may have to be compelled to be humble on this one :).

  10. Your question of “should I drop the ball” speaks very well to the limited role of science, which I don’t think can every be overcome.

    Much of Aristolean physics has been rejected as “more wrong” than Newtonian because it fails to agree with observation. So it’s not a useful model of the universe. I don’t see how that is a subjective judgment. Newtonian physics is a useful model in the same objective sense that Aristolean is not. That is, until we extend it to things that are very big or very small or very fast, i.e. well outside the box of most everyday experience. In those regimes, we have to turn instead to other models that are objectively even “more right” than Newtonian physics. Those models (General Relativity, QM, etc) are “useful” within a larger box, but in order to be “more right”, they must also agree with Newton when reduced down to his box.

  11. Except, Aaron, that Aristolean and Newtonian physics are both wrong. Saying one is *more* wrong than the other requires a metric, which we provide based on our own perceptions, culture, and biases. It’s like saying red is more non-blue than yellow is. It is a useful exercise in that we operate within our perceptions, culture, and biases, but it also ignores our own limitations to claim that our metric is inherent when it’s just canonical.

    Ben F., mathematicians laugh at your scientific hubris. Tremble before our implied certainty! :)

  12. The words red, yellow, and blue are, as you suggest, arbitrary names assigned to arbitrarily bounded intervals of the electromagnetic wavelength spectrum. However, the statement “red is more non-blue than yellow” has a non-arbitrary, not-culturally biased meaning – that the energy of a “yellow” photon is higher than that of a “red” photon. (Even mathematicians allow for unique ordering, I thought…) How we choose to bound the extent of “red” and “yellow” can depend on culture, bias, etc (in the same sense that most human language consists of arbitrarily chosen symbols to represent objects and ideas), but the labels reflect a quality that is inherent, at least to the same extent as length, time, or energy. Similarly, if I drop a ball and compare the measured fall time to the predictions of Newton and Aristotle, and Aristotle is further off than Newton, then his physics is “more wrong” with respect to that phenomenon. I don’t see how that judgment depends on perception, culture, or bias. Just accurate measurement of time.

  13. Brian, we physicists have nothing to fear from mathematicians! It’s not like we would ever in our wildest dreams even think of cutting any corners in our derivations and “proofs”!! :) But to get back to the real discussion, are you suggesting that Aristotelian (sp?) and Newtonian physics are both equally useless since they are both wrong? If so, then all of physics may be equally useless, since the even the standard model is probably just a low-energy approximation of a unified theory. And for many centuries, Newtonian physics was “correct,” in that no one could observe anything in contradiction to it, so did it lose all usefulness in the moment it was discovered that it was an insufficient theory? How would you describe the best way to know if a theory is wrong or right? By suggesting that Newtonian and Aristotelian physics are both wrong, are you actually using one of those “value” judgments you started questioning in the first place? Sorry if I sound antagonistic–I don’t mean to be–I just like this exchange and want it to keep going :).

  14. Aaron and Ben, this is a fun exchange. And no, I did not say Newtonian and Aristotelian (that’s the spelling!) were useless, just that they are wrong. I have no problem with anyone getting a use out of them, but I do have a problem with saying one is *more* wrong than the other. Let’s say a 7 year old’s intuition says Santa doesn’t exist despite what her parents told her and a 37 year old believes Sasquatch doesn’t exist because he’s a biologist and avid camper who’s frequently tried to observe one without success. (In true mathematical form, let’s also assume that neither Santa nor Sasquatch exist.) Is the 37 year old *more* right than the 7 year old just because he’s done some research? Mathematicians love proofs, but we also understand sometimes we see the result before we can prove it (vis a vis Ramanujan) and the Platonist in us recognizes that the result is true or false regardless of whether we’ve researched it or not. Therefore, to pretend that results should only be sought through strict constructivists proofs and not by less repeatable, observable, or experimental means (flashes of insight, dumb luck, intuition) is not only haughty and unwarranted, it’s unwisely limiting.

  15. constructivists -> constructive

  16. Even though I am sad to learn that quantum entaglement doesn’t work (granted, I didn’t even know it existed before reading this post), I just have to say that it makes me happy inside anytime someone compares Star Wars and the gospel.

Follow

Get every new post delivered to your Inbox.

Join 9,823 other followers