A plea on behalf of Schrödinger's cat

I'm going to make a dual plea to all y'all:

1. Before you accept a paranormal or supernatural explanation for something, make sure you've ruled out all the normal and natural ones first.
2. Before you try to apply a scientific explanation to an alleged paranormal phenomenon, make sure you understand the science itself first.

I stumbled on an especially good (well, bad, actually) example of what happens when you break both of these rules of thumb with "paranormal explorer, investigator, and researcher" Ashley Knibb's piece, "Into the Multiverse to Search for Ghosts: Are We Seeing Parallel Realities?"  The entire article could have been replaced by the word "No," which would represent a substantial gain in both terseness and accuracy, but unfortunately Knibb seems to think that the multiverse model might actually explain a significant chunk of supernatural claims.

Let's start out with the fact that he joins countless others in misusing the word dimension to mean "some place other than the regular world we see around us."  To clear this up, allow me to quote the first line of the damn Wikipedia article on the topic: "the dimension of a mathematical space (or object) is defined as the minimum number of coordinates needed to specify any point within it."  We live in a three-dimensional space because three measurements -- up/down, right/left, forward/backward -- are necessary to pinpoint where exactly something is.

So saying that something is "in another dimension" makes about as much sense as saying your Uncle Fred lives in "horizontal."

Then he goes on to mention the quantum multiverse (also known as the Many-Worlds Interpretation), the bubble universe model, and brane theory as possible scientific bases for explaining the paranormal.  First off, I'll give him as much as to say that these are all legitimate theoretical models, although the three have little to nothing to do with each other.  The Many-Worlds Interpretation of quantum theory arises because of the puzzle of the collapse of the wave function, which (in the Copenhagen Interpretation) seems strangely connected to the concept of an observer.  Physicist Hugh Everett postulated that observer-dependency could be eliminated if every quantum collapse results in a split -- every possible outcome of a quantum collapse is realized in some universe.

[Image licensed under the Creative Commons Christian Schirm, Schroedingers cat film, CC0 1.0]

Then there's the bubble universe model, which comes from the cosmological concept of inflation.  This theory suggests that our current universe was created by the extremely rapid expansion of a "bubble" of inflating spacetime, and that such bubbles could occur again and create new universes.  Finally, brane theory is an offshoot of string theory, where a brane is a higher-dimensional structure whose properties might be used to explain the apparent free parameters in the Standard Model of Particle Physics.

These three models do have one thing in common, though.  None of them has been supported by experimental evidence or observation (yet).  For the first two, it very much remains to be seen if they could be.  In Everett's Many-Worlds Interpretation, the different timelines are afterward completely and permanently sealed off from one another; we don't have access to the timeline in which a particular electron zigged instead of zagging, much less the one where you married your childhood sweetheart and lived happily ever after.  The theory, as far as it goes, appears to be completely untestable and unfalsifiable.  (This is what led to Wolfgang Pauli's brilliantly acerbic quip, "This isn't even wrong.")  

And as far as the bubble universe goes, any newly-formed bubbles would expand away from everything else at rates faster than the speed of light (it's believed that space itself isn't subject to the Universal Speed Limit -- thus keeping us science fiction aficionados in continuing hopes for the development of a warp drive).  Because information maximally travels at the speed of light, any knowledge of the bubble next door will be forever beyond our reach.

Be that as it may, Knibb blithely goes on to suggest that one of these models, or some combination, could be used to explain not only ghosts, but poltergeists, "audible phenomena," déjà vu, the Mandela Effect, sleep paralysis, and cryptid sightings.

Whoo-wee.  Sir, you are asking three speculative theories to do some awfully heavy lifting.

But now we get to the other piece, which is deciding that all of the listed phenomena are, in fact, paranormal in nature.  Ghosts and poltergeists -- well, like I've said many times before, I'm doubtful, but convincible.  However, I'm in agreement with C. S. Lewis's character MacPhee, who said, "If anything wants Andrew MacPhee to believe in its existence, I’ll be obliged if it will present itself in full daylight, with a sufficient number of witnesses present, and not get shy if you hold up a camera or a thermometer."  A lot of "audible phenomena" can be explained by the phenomenon of priming -- when the mind is already anticipating a particular input (such as a creepy voice on a static-y recording) we're more likely to perceive it even if there's nothing there in actuality.  (As skeptic Crispian Jago put it, "You can't miss it when I tell you what's there.")  Déjà vu is still a bit of a mystery, but some research out of Colorado State University a few years ago suggests that it's also a brain phenomenon, in this case stemming from a misinterpretation of familiar sensory stimuli.  The Mandela Effect is almost certainly explained by the plasticity of human memory.  Sleep paralysis is a thoroughly studied, and reasonably well understood, neurological phenomenon (although apparently scary as hell).

As far as cryptid sightings -- well, y'all undoubtedly know what I think of most of those.

So the first step with all of these is to establish that there's anything there to explain.  The second is to demonstrate that the scientific explanations we do have are inadequate to explain them.

The third is to learn some fucking science before you try to apply quantum physics, inflationary cosmology, and string theory to why you got creeped out in a haunted pub.

Okay, I'm probably coming across as being unwarrantedly snarky, here.  But really.  There's no excuse for this kind of thing.  Even if you're not up to reading peer-reviewed science papers on the topics, a cursory glance at the relevant Wikipedia pages should be enough to convince you that (for example) the bubble universe model cannot explain ghosts.  Misrepresenting the science in this way isn't doing anyone any favors, most especially the people who seriously investigate claims of the supernatural, such as the generally excellent Society for Psychical Research.

As far as whether there's anything to any of these allegedly paranormal claims -- well, I'm not prepared to answer that categorically.  All I can say is that of the ones I've looked into, none of them meet the minimum standard of evidence that it would take to convince someone whose mind isn't already made up.  But I'm happy to hear about it if you think you've got a case that could change my mind.

Just make sure to tell the ghost not to get shy if I hold up a camera or a thermometer.

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Brane teaser

After my diatribe a couple of days ago about the misuse of the word dimension, I got into a discussion with a friend that can be summed up as, "Okay, then how are we supposed to picture spaces with more than three dimensions?"

Well, the simple answer is that we can't.  Our brains are equipped to manage pictorial representations of three dimensions or fewer.  We can try to get a handle on it via analogy -- a particularly masterful example is Edwin Abbott's Flatland: A Romance of Many Dimensions, which considers a two-dimensional character named A. Square, who has as hard a time picturing a third dimension as we do a fourth.  When a three-dimensional sphere passes through Flatland, A. Square perceives it as a series of successive two-dimensional slices -- a circle that appears out of nowhere, grows larger, then shrinks and finally vanishes.  The implication is that if a four-dimensional object -- a hypersphere, perhaps -- were to pass through our three-dimensional world, we'd see something similar; a projection of successive "slices," a sphere popping into existence, expanding, then contracting and vanishing.

But the fact remains that these are ways of thinking about a concept that is, honestly, beyond our ken.  It's the problem that plagues many of the deep models of physics -- something that can be described clearly and accurately by the math is nevertheless impossible to visualize.  It's a bit like the situation with quantum mechanics; the math is astonishingly precise and makes spot-on predictions, but if you ask most physicists, "So what physical reality is the math describing?" the answer you'll get is a slightly embarrassed "we don't know."  (If they don't say "Shut up and calculate.")

It's a serious sticking point with people like myself, who understand best when we can picture what's going on.  It was when I hit that spot in my undergraduate studies -- when the professor said, basically, "The math is what's real, here, don't bother trying to visualize it because you can't" -- that I decided that a career in physics was not in the cards for me.

Despite that, I have continued to be intrigued with notions like quantum indeterminacy and higher-dimensional space, even though when I read about them I often have an expression on my face like the one my puppy has when I explain a complex concept that is beyond his comprehension, such as why he shouldn't eat the sofa.  I'm currently reading a wonderful book about the topic of extra dimensions, by the brilliant theoretical physicist Lisa Randall, called Warped Passages: Unraveling the Mysteries of the Universe's Hidden Dimensions, which does an outstanding job of bringing the topic down to a level we eager-but-not-so-bright puppies can understand.  (And if you want more, she has an appendix with mathematical notes elucidating the topic in a deeper and more precise fashion.)  

One of the more fascinating topics she goes into is the concept of a brane -- a cross-section of a higher-dimensional space a bit like A. Square's expanding-and-contracting circles.  The name comes from the word membrane, because (like a cell membrane) a two-dimensional brane can be a boundary on a three-dimensional space.  The surface of the Earth's ocean, for example, can be seen as a two-dimensional brane (not only acting as a boundary, but oscillating up and down into the three-dimensional space on either side).

Of course, you're not limited to two-dimensional branes in three-dimensional space.  A generalized name for branes in p dimensions is called a p-brane, which was one of my father's favorite insults (albeit spelled differently).  

A two-dimensional representation of a three-dimensional projection of a six-dimensional structure called a Calabi-Yau manifold.  Yeah, my head hurts, too. [Image licensed under the Creative Commons Andrew J. Hanson, Indiana University., CalabiYau5, CC BY-SA 3.0]

Where it becomes more interesting, and unfortunately far harder to picture, is when you consider the idea from some physicists -- Randall has been one of the lead researchers in this field -- that our own three-dimensional universe is a three-brane within a higher-dimensional space.  There is a tantalizing suggestion that this model may explain some of physics's most persistent mysteries, such as why the gravitational force is so weak compared to the other three.  If we are actually living in a three-dimensional slice, the gravitational force within our bit of space may leak across into the higher dimensions,  weakening its intensity and perhaps influencing other branes within the space (which might give physicists a way of finding evidence for the conjecture).

There's even the suggestion that the Big Bang may have occurred because of collision between two three-branes in a multi-dimensional hyperspace -- a model called ekpyrotic cosmology.  

But we're still up against the problem that it's impossible to answer the question, "But what does it actually look like?"  The mathematics is crisp and clear; any picture we come up with is, by comparison, incomplete and inaccurate.  Take, for example, a hypercube, a symmetrical four-dimensional structure that can be described mathematically but is impossible to visualize.  All we can do is consider what projections of it -- shadows, so to speak -- look like in three dimensions.  Here's a particularly mesmerizing projection of a rotating hypercube:

[Image licensed under the Creative Commons Jason Hise, 8-cell-orig, CC0 1.0]

So we're kind of ending where we started.  All of this is just a teaser, really -- a brief excursion into a subject that is just now being investigated by some of the most brilliant minds on the planet.  If the mathematics of branes and higher dimensions and whatnot is beyond you -- it certain is me -- we're left with trying to get a faint glimmer of understanding via analogy.  Which only gets you so far.

But at least it gives us something our branes -- um, brains -- can handle.

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