Welcome to the Bicentennial Celebration: This Is Ctein Column Number 200*! I felt like I needed to do something really special with this column. So, I'm going to mess with your heads. Lots.
If you thought my columns last Christmas were messing with your heads...
The Unseen Universe Gets Much Weirder (Very OT!)
...this time it's going to be a lot, lot worse.
Let me begin by explaining to you the idea of "local reality," a term used by physicists.
The first word is "local": in physics, this is actually a very strong word. For example, I can say the moon is globally a sphere, and you can confirm that for yourself just by looking at it. "Global" means that it's true taking the broad viewpoint. If I were to say the moon was "locally" a sphere, it would mean that it looks spherical at every size; no matter how close I got it would remain a perfectly shiny, perfectly spherical marble. "Local" means that we consider something to hold true everywhere, all the time, on all scales.
"Reality" means something very specific, but it's fairly commonsensical. Local reality has three characteristics:
• Causality: things happen for a reason. We may not know what the reason is, but still.... If my teacup suddenly takes off and starts flying around the room, I assume it happens for a reason. Maybe it's alien influence, maybe it's because someone put drugs in my teacup (I'll get back to that), maybe it's because I have poltergeists, maybe it's a miracle delivered to me personally by God. Something made it happen. It's hard to object to that.
• Objectivity: the things that we measure that we think are real really do have an existence independent of our imaginings. That teacup flying around the room? Unless someone has drugged my tea or I've gone insane, I assume it is there. If I make a photograph of it, I assume the photograph is real and what was photographed is real. If the tree falls in the forest, it does make the air move in a way we would hear as sound if we were there, even when no one is there.
(Lots of aspects of the world are subjective. If I ask you if you like pepperoni pizza, your answer is an objectively observable utterance, but your like or dislike of it is not.)
Like causality, objectivity is hard to disagree with. You can construct all kinds of philosophies where we are all living inside our own dreams or someone else's simulation, etc. But how many of us really believe that?
• Induction: this is a little more subtle, but we take it for granted. It's the belief that there is basically a logic to things. If we say that A always causes B and B always causes C, then A always causes C. Induction implies repeatability, which is at the heart of making any kind of an observation. I push the teacup off the table, and it falls to the floor. If I do it again (causality), and the teacup is really there and I really did push it (objectivity), then it should fall to the floor again...unless something has changed that causes it to fly around the room (back to causality).
That's what physicists mean when they talk about local reality, and it would be very hard for most of us to disagree that this is a quite sensible description of our basic experience with the world.
There's a slight problem. It's wrong. We can prove that the universe does not obey local reality and that at least one of our three assumptions has to be in error. We can do experiments in which things happen that are simply impossible according to local reality. I shall explain:
Simple logic can tell you how certain kinds of experiments will come out. Suppose I want to do a survey of cereal boxes in the supermarket. I'm going to count the total number of cereal boxes. Then I'm going to count the number of boxes that have sugar added. Finally I'm going to count the number of boxes that have no added sweeteners of any kind (those could be artificial sweeteners, sweet bits of candy or fruit, etc.; they might not be sugar). What can you tell me about the results?
It should be obvious that number of boxes that have added sugar plus the number of boxes that have no additional sweeteners of any kind must be no more than the total number of boxes of cereal on the shelf.
In general terms, Ctein's Inequality: [total items] is greater than or equal to [items with A] + [items without A thru Z]
This statement is not bulletproof. It does require some basic logic—those postulates of local reality. If the cereal boxes aren't really there or if counting them does not produce a predictable, reliable, and reproducible result, then my inequality can fail. But we would expect that in a normal, sane world, it will work.
Houston, we have a problem
Now, back to the world of physics labs rather than supermarkets.
Half a century ago, an amazing physicist named John Bell did this kind of logical analysis, figuring out what sorts of results we could expect from experiments. He came up with one called Bell's Inequality, a more sophisticated and useful version of my cereal box inequality. You can look up the details on the web. Its underlying logic demands nothing more than local reality; if that holds, Bell's Inequality applies.
In the late 1970s, a couple of physicists came up with a design for a quantum mechanics experiment that had an odd characteristic. They could calculate, using QM, what the results of the experiment should be. That prediction was in conflict with Bell's Inequality. So, of course, they ran the experiment! I do not know, but I strongly suspect that they were expecting to find a subtle flaw in quantum mechanics this way. No one thinks quantum mechanics is the be-all and end-all of physics, while local reality is awfully fundamental. So I imagine they believed the experiment would show some problem with their calculations which would lead to new, more interesting physics.
The universe threw them (and us) a curveball. Their experimental results matched their quantum mechanical calculations. The results were in violation of Bell's Inequality. In other words, the results were impossible if local reality were true.
Understand the import of that. This is not about whether or not quantum mechanics is right or wrong; quantum mechanics might very well be wrong in some way, although this experiment didn't find it. What this experiment said, though, was that local reality was unquestionably wrong.
Essentially, it was as if I had gone into the supermarket, did my cereal thing and counted that there were 38 boxes of cereal total, 23 of which had added sugar and 19 of which had no added sweeteners of any kind.
Houston, we have a problem.
First and most reasonable hypothesis: their experiment was flawed. Either their measurements were in error in some way, they were not measuring exactly what they thought they were measuring, or other factors they hadn't accounted for were intruding and messing up the experiment. That reasonable assumption hasn't panned out. In the intervening 30 years, the experiment has been refined dozens of times, and run by many different researchers.
With the advances in electronics and measuring devices, it's really at no more advanced a level today than college physics; it it might even be doable in a good high school physics lab. The results are pretty much bulletproof now—and they consistently violate local reality. Furthermore, people have come up with other experiments that measure different kinds of things that also violate Bell's Inequality.
So, it's not just one isolated case where local reality fails, although most of the time it works just fine. Regardless, reality is not supposed to be a sometimes thing. It means that we really don't understand what's going on, that our conceptual model is somehow fundamentally flawed.
So, which of our assumptions is wrong? Objectivity? Causality? Induction? Throwing out any of those makes reality a peculiar, disturbing, and very unfamiliar place. Yet we know that one of those (maybe more than one) isn't always true, it's just usually true.
Physicists lean towards throwing out objectivity; there's already been some thought for doing that in both philosophy and quantum mechanics. But that's entirely an emotional preference born of familiarity; we really don't know. Besides which, throwing out objectivity raises those deep and nasty philosophical questions like Schrödinger's cat, and what effect does an observer have on the whole universe, and what does observer really mean when we are all part of one universe, and even more tie-your-head-in-knots conundrums.
Remarkably, physicists are starting to come up with experiments that can test which of those assumptions is wrong. That work is still in its early phases, and there is not entire agreement on the results, although it is looking like objectivity may be down for the count. Which, even if that's true, doesn't mean it's the only one of our assumptions that falls. If one of them is wrong, maybe all of them are wrong. Mildly scary thought.
What's truly astonishing, though, is that we are entering an era of experimental philosophy. Understanding the fundamental nature of experience and reality used to be limited to the great armchair theorists of our philosophy classes. Now people are actually figuring out physical experiments that may illuminate matters that we thought were entirely beyond the realm of experimentation.
Want to know my utterly wild-ass guess? I think, philosophically, we just plain have it wrong. I think we're in a stage akin to alchemy: we talk about things like "observers," "events," "measurements," and "objects" believing that these are fundamental components of reality. I think we're going to find out that they are philosophical Elementals, the equivalents of earth, air, fire, and water. They are undoubtedly real, but they'll turn out to not be fundamental building blocks of reality.
Like I said, wild-ass. And I wouldn't even try to guess what real philosophical "elements" might look like.
In 50 years, though, I think we will know something. Experimentation proceeds.
*(There is a bit of ambiguity in the data; technically this could be construed as anywhere between Column 198 and Column 202. By my arbitrary numbering system, it is 200. It's my party, and I'll cry if I want to....)
Ctein, a physicist by training, is a photographer, parrot aficionado, sci-fi fan, and—as the author of well over 500 articles published in photography magazines over five different decades—perhaps the most experienced phototechnical writer in America. His regular weekly column on TOP, not always confined to matters photographic but usually conventionally reality-based, appears on Wednesdays.
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Original contents copyright 2011 by Michael C. Johnston and/or the bylined author. All Rights Reserved.
Featured Comment by Melv: "Eh?"
Ctein replies: I think "Whaaaaa???" might be more appropriate (g).
Featured Comment by Hugh Crawford: "I like the many-worlds interpretation with no wavefunction collapse , and not just because it was thought up by some other guy named Hugh (Everet). Flip a coin, create a universe unless it turns out that time is running backwards and you are consolidating two possible 'futures' into one 'now' I'm just glad to be in the universe where Ctein writes his off topic pieces about quantum mechanics and not golf. I just don't get golf at all."
Mike replies: It's harder than physics.