Quantum Enigma: Physics Encounters Consciousness
by Bruce Rosenblum and Fred Kuttner
Big thanks to Rob Kroese (@robkroese on twitter) for recommending this cool book, after I mentioned my zeal for grandiose theories-of-everything, especially physicists who dabble in consciousness. This book is an excellent, no-nonsense down-to-earth review of the whole consciousness-in-quantum-physics question, that doesn’t fly off into shaky pseudoscience but yet conveys just how central consciousness is to quantum physics. (Maybe.) The authors are a couple physics professors — the book grew out of a course they gave to non-physics-majors that attempted to give a taste of how damn weird quantum mechanics is. That class must have been a blast.
They mention something about quantum mechanics that probably comes as a surprise to non-physicists — that when you get beyond the popularizations and Nova specials, it can be kinda *boring*. Let’s say you step up from reading layman-level popularizations of quantum physics, and you start taking a QM class. As you actually get into the nuts and bolts of quantum mechanics, you quickly lose sight of all the philosophical issues, the weirdness, the unsolved aspects — all the *cool* stuff. You get good at solving problems, learning the rules, applying the sometimes-clunky approximations, passing exams, etc, and ironically gradually stop thinking as deeply about quantum mechanics as novices reading the popularizations. And this isn’t accidental — your professors in your QM class probably don’t bring up the philosophical debates, because they don’t understand it either. I personally wound up enjoying my coursework in classical mechanics (essentially Newton’s Laws on steroids) much more than QM courses, and even skipped the last quarter of it in grad school.
The strange thing about QM is that it works, really really well, but we still don’t really know *how* it works. While that’s technically true for other physics topics, you don’t have to dig very far to get to the unresolved questions in QM. Unlike in say relativity, in quantum mechanics the mysteries are right on the surface. Some of the basic tenets of QM, things like how exactly a quantum state “collapses” when it is observed, are just complete mysteries. In fact this book centers on that exact question — how, exactly, does the act of observing something change its quantum mechanical state? In terms of the famous Schrodinger’s Cat example, just how exactly does the act of observation “collapse” the cat’s wavefunction?
The amazing answer to this question is: I dunno. Nobody knows. We can tell that it happens, we build it into our quantum-mechanical theories, we know the effect that observation has on the thing we’re observing, but we don’t really know what the hell “observing” means in terms of quantum mechanics. And this leads to a whole mess of crap that is both wonderful and frustrating…
This leads to an idea inside modern mainstream physics that is probably weirder than 90% of the pseudoscience new-age nonsense out there today. This idea is right smack-dab in the middle of a universally-accepted physical theory, discussed by honest-to-god real physicists (not just crystal-wielding hippies [no offense, if you're wielding a crystal right now]), and was debated among physicists you’ve heard of, people like Einstein, Schrodinger, and Bohr. The idea is that *consciousness* somehow intimately affects the physical world through quantum mechanics. I don’t mean the no-duh effect my consciousness has on the physical world when I decide to break my coffee cup, I mean that somehow *consciousness* is required as a direct part of quantum mechanics. That an actual conscious being is required to do the “observation” thang in quantum physics.
E******n In A Box
Other people have described quantum physics better than me, so I’m assuming if you’ve read this far, you either know the basics or are reading this as a direct personal favor to me. But let’s talk about the quantum-mechanical picture of a single electron. You’ve heard that an electron in the wild has no particular location until you observe it. When an electron is “observed”, it goes from some spread-out wave thing to a discrete particle, localized in space. (I imagine a little tiny “pop” sound.) Maybe a little scream.) But what does “observed” mean?
Some ruthless, cold-hearted, no-nonsense physicists would say “observed” really means just physically interacting with something else, not literally a conscious, living observer with a brain. For example, a microscope looking at the electron by shining light on it would “observe” the electron, thereby collapsing its wavefunction solely through the shower of photons hitting it. But, the other physicists would argue that this wouldn’t really be an observation, that it wouldn’t collapse the wavefunction. For example, if you threw some photons (light) at an electron (by turning on your microscope light), those photons would interact with the electron, and the electron-plus-photon system would have a joint wavefunction. *Microscopic* things you throw into the system will find themselves getting sucked into the nebulous quantum superposition state, not collapsing the wavefunction like you’d hoped.
Let’s pick a simple example — an electron rattling around in an otherwise-empty shoebox. Before you “observe” it, the electron is spread out over the entire box, in a quantum mechanical state with no fixed position or velocity. When you open the box and look around, you’ll find the electron *is* at one particular position in the box — you (somehow) collapse its wavefunction, and now it is in a new, much simpler state. When physicists try a version of this experiment, they do indeed find the electron’s wavefunction collapsed, and further they can prove the electron was in a weird smeared-out wave state before it got collapsificated. This is actually demonstrable in the lab.
But that’s a hell of an intrusive observation — you turned on the light, showering the electron with photons. Maybe you stuck your hand in there and felt around, thereby bombarding the electron with collisions from millions of other atoms that are in your hand. You might therefore wonder, maybe we shouldn’t pin the wavefunction collapse on me having a conscious, aware human brain — maybe instead it has to do with the heavy-handed bombardment of this poor electron that I’m doing by trying to “observe it”. And you’d be right. So let’s try something else — try to do the very smallest, least-intrusive observation you possibly can. Just throw a single photon in the box — just one quantum of light, shove it in there and let it go find the electron for you. In this other extreme, you are perturbing the electron as little as you possibly can. What happens in this case? Instead of collapsing the wavefunction, the photon winds up *in a quantum state with the electron* — the photon now gets its own wavefunction, and together the electron-plus-photon are in a joint quantum superposition of states. The photon doesn’t get to “observe” — instead, it becomes part of a joint electron-and-photon system, which someone else will now have to observe in order to collapse the superposition of states.
(I’m big-time oversimplifying the situation here, and anyone whose taken a physics class is currently ripping out nose hairs in frustration over the idea of reaching into a box to feel around for a single electron, but I’m just trying to convey the gist.)
Why didn’t the photon get to “observe” the electron? Does it not get the superpower of observation? How does it get promoted, so it can collapse wavefunctions on its own, not just get pulled into some joint quantum state with the thing its observing? Is there something simpler than a whole intact human being that has the power of observation? Somewhere in between a single photon and a big ol’ giant human, is there a dividing line where sufficiently-complex beings are granted the permission to collapse wavefunctions?
This was actually the point of Schrodinger’s Cat concept — Schrodinger conceived it to point out how *ridiculous* quantum mechanics sounds, and ironically his critical intent is now forgotten in pop culture references. Is the cat in a “superposition of alive and dead”? Why doesn’t the cat itself count as an observer, who could collapse the wavefunction of the decaying atom itself, and thereby wind up either definitively alive or dead? Do we “observe” and therefore collapse the wavefunction when we open the lid? What if we shake the box up a bit? If the cat plays dead when we shake the box, and we “observe” the wrong answer, what happens then?
Schrodinger was right — it *is* ridiculous. To this very day we still don’t know what constitutes a quantum-mechanical “observation”, who exactly has the power to pop a wavefunction, versus who winds up entangled into the quantum state with the thing you’re observing. You can go down one of a couple paths here, and they’re both pretty ridiculous. So let’s go down them!
Ridiculous Path No. 1: There’s No Such Thing As Collaspsing Wavefunctions
What if you (reasonably) decide that there’s nothing magical about consciousness, that after all we are made of electrons and protons and whatnot, and so there’s nothing inherently special about *us* that can collapse wavefunctions? Hell, maybe we don’t — who’s to say we ourselves don’t get pulled into a quantum-mechanical superposition of states with the cat in a box? Maybe, *nothing* in the universe can actually collapse a wavefunction, and we’re all in one big fat gigantic universal quantum superposition state, everything in the universe included, and with nothing outside the universe to “observe” and therefore collapse the wavefunction.
If so, then ironically there’s nothing random about quantum mechanics — the universe has one big fat giant wavefunction, and since there’s nothing to “pop” it, it just continues on in its perfectly predictable way until the end of time. (The randomness comes about only when a wavefunction is collapsed to a simpler state — before you observe and collapse a wavefunction, it just meanders along perfectly predictably. Quantum mechanics without a concept of “observation” that collapses a wavefunction is completely deterministic, just like Newton’s laws.)
All righty then… but why does it “look” to us like there are collapsing wavefunctions? And randomness? And if the universe is in some giant mega-quantum state with no inherent randomness, does that mean the entire universe’s history is predetermined? So what happens to our free will then?
Where could this possibly lead? To infinite parallel universes, of course! One idea, proposed by Hugh Everett (father of Mark Everett, the lead singer in the band The Eels), is that when a superposition state (like the alive/dead cat) appears to collapse, it really SPLITS THE ENTIRE UNIVERSE — two copies of the universe continue on from that point, with one containing a live cat, the other a dead cat. The two copies of you go on with their lives in their respective universes, completely unaware of each other. Every single apparent wavefunction collapse in all of creation actually generates new universes. There, problem solved! For the small cost of INFINITE PARALLEL UNIVERSES BEING GENERATED EVERY INSTANT, we have avoided the puzzling question of the role of consciousness in quantum mechanics. While this sounds like it would make Occam use his razor to slit his own wrists, it’s a clever idea and is well-regarded by many physicists — while not the prevailing interpretation of quantum mechanics, a significant minority of physicists think this might be real.
Ridiculous Path No. 2: We are a lot more important than we thought
The other extreme, believe it or not, is even weirder. Now we have to assume that there’s something fundamentally different about “observation” — that some things in the universe can “observe” and thereby collapse something else’s wavefunction. That the act of measuring something is itself something fundamental, its own special place in the laws of physics along with time, space, forces, energy, etc. Many physicists have concluded that *consciousness*, perhaps human consciousness, actually does the wavefunction collapsing. They know full well this sounds ridiculous, but its better than the alternative — after all, why *aren’t* we as humans pulled into a quantum-mechanical superposition with the electron, or with the cat?
Well, when I say “many physicists”, in truth most physicists simply ignore this question entirely, concluding that the nature of an “observation” is yet to be discovered. The prevailing view of quantum physics (called the Copenhagen Interpretation) just describes an “observation”, without explaining who gets to observe and who doesn’t. But a minority of physicists feel the search for what could possibly do the observing leads inevitably back to an aware conscious mind. Eugene Wigner, for example, extended the Schrodinger’s Cat thought experiment to include somebody else *observing* the dude who observes the cat — if Wigner does the cat-in-a-box experiment in his lab, alone, and later a friend comes to check on him, is Wigner in a superposition of states? Wigner argued that no, the chain of quantum mechanical states stops when he (a conscious observer) collapses the wavefunction of the cat-in-the-box. Since then, many physicists have actually seriously pondered whether human consciousness and observation have a physical effect on the universe. For example, Larry Krauss put forward the idea that us observing the universe might change the entire universe’s wavefunction, thereby hastening the end of the freaking world. And of course tons of pseudoscientists and new-age philosophers have taken off from here to posit all sorts of strange interrelationships among consciousness and the universe. (You can tell I’m skeptical of them, particularly ones who use half-baked quantum theories for personal financial gain. I’m lookin at you, Deepak .)
And that gets us back to this book. (Remember? This was supposed to be a book review. I almost forgot also.) Bruce Rosenblum and Fred Kuttner are both mainstream physicists, with no new-age inclinations, who nevertheless are just as baffled by this seeming intrusion of human consciousness into the physics of microscopic particles. To their credit, they don’t presume to have an answer, instead they lay out the entire problem for the layman in this book, starting at a completely non-mathematical explanation of basic quantum physics and leading right up to a tour of the various attempts to explain the consciousnesss/observer issue.
Oh yeah, the book…
About the first two-thirds of the book is devoted just to explaining the basics of quantum mechanics in a way the most math-averse could understand. It isn’t easy reading, by any means, but if you’re interested in QM and are willing to put in some thinkin’, you can learn the essence of QM from these guys with nary an equation or mathematical symbol in sight. As they get towards the end, they give a fascinating overview of the struggles the founding fathers of QM faced in wrestling with the nature of the observer. Neils Bohr and Albert Einstein, in particular, debated the true meaning of quantum mechanics for decades after the Copenhagen Interpretation was worked out in the ’20s. (Parenthetical note: Einstein, who is now famous for being critical of QM ["God does not play dice!"], was arguably the *founder* of quantum mechanics. His early paper on the photoelectric effect was just the 2nd paper ever that used quantum-mechanical ideas, and was the 1st paper to consider it physically real and not some sort of math trick to make the numbers work out right. Einstein gets very little credit for being the 1st person to take quantum-mechanical ideas seriously.)
Towards the end, the authors give us a quick tour through all the various interpretations of Quantum Mechanics — nearly every big-shot theorist has given it a shot at explaining how QM works, particularly how to tackle the problem of observation and consciousness. These are by necessity very short overviews, and left me wanting more — but they are fascinating. There’s the story of Bell’s Theorem, that proves that the collapse of a wavefunction for a system can somehow *travel faster than the speed of light*, pissing off Einstein to no end. (Imagine entangling together two electrons in the same quantum state, then let them fly off into the sunset in opposite directions, still entangled. If you observe one, the other instantly gets collapsified too.) There’s the recent experimental attempts to try to get something bigger than an electron into a quantum superposition state, preferably something macroscopic enough to see with your eyes.
The authors even get into the purely philosophical problem of the mind / brain problem — is our conscious awareness solely a physical process, arising just from biochemistry and neuroscience? Or is their a “ghost in the machine”, something beyond molecules & chemicals, something that makes the mind distinct from the brain? This is obviously a huge area, but the authors give a fascinating (but quick) overview of how the mind/brain problem is given a quirky new perspective thanks to QM.
Finally, towards the end they briefly touch on what is probably my favorite part of this whole crazy mess — theories that turn the whole problem around and propose that somehow quantum mechanics is *responsible for* consciousness. The most well-known is the work of Roger Penrose, a Certified Badass cosmologist who has collaborated with Stephen Hawking, and more recently proposed an unbelievably grandiose theory that ropes in an as-yet-undiscovered theory of Quantum Gravity to show how quantum effects are the cause of consciousness and free will. These theories fascinate me to no end, and one of these years I will finish my article profiling these guys.
Oh yeah, the end of this book review…
Okay, let’s wrap up this book review before it gets to be longer than the book itself. I certainly didn’t give the idea of quantum mechanics and its relationship to consciousness full justice in this review, but hopefully I gave you a taste of how strange it all is, and how this mess is right in the middle of a fundamental physics theory, not just on the fringes. It’s a blast, its a mess, and, much like the authors of this book, I believe it’s nowhere near close to being solved. But if you’re looking for an entertaining review of the whole shebang, give this book a try.