Tuesday, May 19, 2015

Quantum Of Distress

Science is hard.

But more than that, science is hard to keep up with. Everyday it seems like there's a new discovery being made that completely changes our understanding of the Universe. If you had told me a couple weeks ago someone invented a real-life reactionless drive using only the magnetron from a microwave oven and the contents of his garage I would have said you're a dirty liar. But now look, NASA is experimenting with a reproduction of that very same device and they still haven't come up with a good explanation for how it works.

As someone who writes science fiction semi-regularly I find the burden of scientific accuracy a little overwhelming at times. I could spend months designing a fictional rocket and all it's components; the nuclear reactor, the deck plan, weapons and give it the most robust and accurate engineering I can. And sure, I could sell the idea to Reader's Digest and rake in millions. But it will all mean exactly zilch if a few weeks after publishing NASA appears and announces they've invented honest-to-God anti-gravity. It's impossible to keep up with every new scientific discovery and sooner or later any piece of science fiction will succumb to what TVTropes calls Zeerust.

I accept that everything I write here and now will one day be seen as dated, even quaint. But if my fictional universe is doomed to being hopelessly antiquated then at least it's going to be consistent.

Here in 2015, there are dozens and dozens of theories regarding the possibly quantum nature of gravity. Some of these were formulated simply to reconcile General Relativity with Quantum Mechanics (two very very different fields with completely incompatible equations), while others have the lofty goal of becoming a so-called Theory of Everything, a theory so complete in it's description of the physical world that it can predict and explain every aspect of the physical Universe.

As for potential Theories of Everything or the less ambitious Grand Unified Theories, there's plenty of candidates to choose from. Of course you have String Theory, the lesser known but still very interesting Loop Quantum Gravity and ugly ducklings like Supergravity or Euclidean Quantum Gravity. The problem is that there's so many to chose from and none of them can be experimentally verified. All these theories concern themselves with either very small or very energetic environments; conditions we're physically incapable of interacting with. So who knows what's really going on down there. We certainly don't, because our giant, fat instruments make a mess of everything we're trying to observe. This is part of the reason why some believe the Heisenberg Uncertainty Principal isn't due to the actual nature of subatomic particles, but is actually a result of the limitations of our giant Human measuring equipment.

The point is that any one of these theories could be correct and I have no way of knowing which one that might be.

I'm getting ahead of myself of course. Because before we can even hope to unify Relativity and Quantum Mechanics we need to figure out how we've even supposed to interpret Quantum Mechanics. As you know, Quantum theory is very strange, some would say frightening. Much of what goes on down there is open to interpretation and the math supports plenty of daffy ideas. For example, when you take a measurement of a particle's position or momentum (but not both), what's really going on? Was the particle behaving like a wave and you've just collapsed it into a particle? Are you getting interference from an unseen pilot wave? Or have you inadvertently created an alternate timeline where your measurements were different? Nobody knows.

The most common interpretation by a wide margin is of course the Copenhagen Interpretation. It has the distinction of being the most widely accepted and visible interpretation and also the one with the most crazy stuff going on under the hood. This is the one that gives us such weirdness as wave-particle duality and wave function collapse; strange circumstances that probably don't even accurately describe the nature of subatomic matter but is as close as we're going to get to really understanding it using our feeble Human minds.

Then there's Pilot Wave Theory which asserts that the bizarre behavior of particles has less to do with them being probabilistic bundles of energy and more to do with 'hidden variables' called pilot waves: ripples particles leave in the fabric of space-time as they pass through. These waves 'remember' the path the particle took and influence the motion of all subsequent particles that pass through it, providing a handy explanation for unusual behavior like what's observed in the famous double-slit experiment.

Or you could stick with the old sci-fi standby of the Many Worlds Interpretation and toss all those sticky questions regarding wave-functions in an alternate timeline.

But this is just the tip of the iceberg. There's a plethora of unanswered questions in physics and each one could have a potentially bizarre answer that totally changes our understanding of reality. For example, what is the origin of mass? We don't know because the concept of mass is so intertwined with gravity and like I said earlier, we don't know what gravity even is at the quantum level. Is mass actually the symmetry breaking Higgs field? W Z Bosons we haven't detected yet? Nobody knows.

How can neutrinos of a specific lepton flavor suddenly have an entirely different flavor? Do they spontaneously transform into a different particle?

Why is there so much more matter than anti-matter in our universe?

What is dark matter and dark energy? Is it zero-point energy? The cosmological constant? Another universe absorbing our own?

Who knows how long it'll take to answer all these questions. Some of them might never be answered. Well, I am not a scientist. But I am someone aiming to write a gripping sci-fi yarn so a few weeks ago I decided I wasn't going to wait for real results from the LHC. Instead, I'll come up with my own fictional Grand Unifying Theory; one that was complete in it's description of the physical universe, that was consistent with all our experimental data so far and allowed for plenty of wacky circumstances like negative mass, anti-gravity or the Alcubierre drive; phenomena conducive to a good science fiction story that haven't been disproven yet.

I call my fictional theory the Theory of Choice as it'll be fine tuned for exactly the sort of stories I want to tell and take all of what I consider the most interesting and probable explanations that are floating around in the physics community right now.

In all likelihood, my pet theory will be disproven ten, maybe twenty years from now. But in the meantime it'll serve as a good framework for the physics of my fictional universe, providing consistent and (hopefully) reasonable explanations for how all the technology therein works. And if any particular element gets disproven (like dark energy ends up being angry ghosts or something), well, I never said my fictional universe was supposed to be our universe. I'll just say in a press conference that my intellectual property takes place in an alternate timeline, similar to our own but with subtly different laws of physics. Until then I can claim perfect scientific accuracy.

How the Theory of Choice works is that I make a few sweeping assumptions about physics and from there, pick the real scientific theories that best fit those assumptions and slowly move down the list of unanswered questions , using explanations from the aforementioned theories until everything is more-or-less ironed out. It's slow going, partially because there are just that many unanswered questions in physics but mostly because I am dealing with heady scientific topics most laypeople don't even know exist. I still have no idea what CP Violation is but it's important and because it's important I have to pretend I'm an actual astrophysicist and try to wrap my head around it.

First, the assumptions: in the ToC, the universe is probabilistic, not deterministic. Second, gravity is quantum but Relativity and Quantum Mechanics go ultimately unreconciled. Third, the origin of mass lies in the Higgs field, the Higgs Boson is not the only such particle of it's type and there are many more left to be discovered, each one capable of more and more bizarre gravity-like effects than the last. Finally, no matter what, the ToC must allow for travel to alternate realities, each more terrifying than the last. This last point is the most important as it allows the antagonists of my work to kill far more people than the total population of any one universe.

Right away, I can say that String Theory has no place in my fictional universe. It's not that I think String Theory is necessarily wrong or bad. I just feel like String Theory has ballooned far out of proportion and makes a lot of assumptions that aren't going to hold up to real-world experimentation. As of this writing, there's virtually no experimental evidence for String Theory and yet it enjoys widespread acclaim and support as the most likely candidate for the fabled Theory of Everything. Plus, String Theory's implication of an orderly and elegant universe is totally at odds with the kind of story I want to tell. String Theory describes an intricate tapestry of 11-dimensional manifolds, where matter arises from the subtle vibrations of mysterious bundles of energy. Well not here it isn't. My universe is a violent, unwholesome place; a cosmology of terror where life counts for nothing and there are only three spatial dimensions.

In my universe, there is no Theory of Everything and the interaction between gravity and the three fundamental forces is ultimately hazy and indistinct. There might not be a Grand Unifying Theory either, meaning there was never a time when electromagnetism and the weak and strong nuclear forces were unified as a single fundamental force. This goes back to the idea of a probabilistic universe. Here at least, God really does play dice with the universe. Everything that occurs in the subatomic world is hazy and left to chance, meaning that at it's most basic level, the universe is open to all sorts of unsettling unrealities.

This is why Pilot Wave Theory has no place in my universe either; it offers a logical, deterministic explanation for the strange behavior of particles with the introduction of pilot waves, injecting reality back into the study of Quantum Mechanics. Determinism and the idea that there is a logical, mechanical explanation for everything his has no place in my chaotic, ultimately nihilistic universe. Instead, I'll probably end up sticking with a modified form of the Copenhagen Interpretation, but it has problems of it's own.

The crux of the Copenhagen Interpretation is the wave function collapse: before observation, particles are in superposition where they occupy any number of energy states and locations. But after observation the wave 'collapses' and the particle inhabits a single energy state. Many have interpreted this as meaning a conscious observer is an essential part of quantum mechanics and that the conscious mind plays a large part in shaping the nature of reality itself. I want to avoid this as it opens the door to a lot of New Age mysticism and other hippy-dippy nonsense I don't want to be involved with. Plus, this mindset kind of implies magic is involved.

Now don't get me wrong, there is magic in my setting, but it has it's own rules unrelated to physics at large and the less said about the quantum mind, the better.

Instead, I'll probably stick with something closer to the idea of Quantum Decoherence. But it's implications are little more far reaching than what I'm comfortable with. If I end up sticking with this route then I might not be able to justify the existence of quantum computers in my setting, something I'm not too eager to let go of.

As for dark matter and dark energy; I think I'm going to stick with main stream opinion on these two. I'll claim that dark energy has actually been the cosmological constant this whole time, similar to what's proposed by the Lambda-CDM model. Dark matter  is composed of weakly interacting massive particles (also known as WIMPs). This is the detritus left over after the Big Bang which have been counteracting the force of gravity ever since. Of course, there have been a few other interesting ideas regarding the identity of dark energy. My favorite comes from Christos Tsagas who in a paper published in Physical Review D claimed that there is no such thing as dark energy. Instead, the apparent expansion of the universe we observe is actually an illusion caused by the relatively fast motion of our corner of the universe compared to our neighboring galaxies. If he's right then all this fuss over phantom forces is ultimately pointless.

Beyond that, I like the idea of there being no supersymmetry as it reenforces the idea that this universe is altogether 'broken' or 'inelegant'. What this means for the aforementioned CP violation, I don't have a clue, but I might allow for spontaneous symmetry breaking. It's just something I'll have to work out later.

Finally, there's the question of the ultimate fate of the Universe. Personally, I prefer a scenario like the Big Rip destroying everything in the end, because it's more horrifying that way.

The Theory of Choice is an ongoing project, probably one I won't be finished with for many years, if at all. It relies on the work of actual physicists for me to iron out, so really nothing has changed. I'm still have to follow the latest news from scientific journals and letting their discoveries inform the nature of my science fictional universe. But the point is that the Theory of Choice is consistent and will make it easier to make a timeline of technological progress in this nightmare vision of the future. Plus, it'll be easier to keep track of just what each technology is capable of.

Do I think the real, physical universe is as probabilistic and inelegant as this fictional universe? It's hard to say really. Pilot Wave Theory was suppressed throughout much of the twentieth century in favor of the Copenhagen interpretation. Given the chance, I think it could have gone a long way to describing the physical world. But as it stands, Pilot Wave Theory is tragically under-researched and nowhere near as robust as the Standard Model, which I think will stand the test of time no matter how clunky it is. I think our desire to unify all the fundamental forces and find the superpartners of all the particles is a natural human tendency to see order and symmetry in every system we encounter. We just naturally like things to make sense, even if the universe might not on some hidden, fundamental level.

With that in mind, I still think String Theory is a load of malarkey.