Wibbly-wobbly...

Have I told you my favorite joke?

Heisenberg and Schrödinger are out for a drive, and a cop pulls them over.

The cop says to Heisenberg, who was driving, "Hey, buddy, do you know how fast you were going?"

Heisenberg says, "No, but I know exactly where I am."

The cop says, "You were doing 70 miles per hour!"

Heisenberg throws his hands up in annoyance and says, "Great!  Now I'm lost."

The cop scowls and says, "Okay, if you're going to be a wiseguy, I'm gonna search your car."  So he opens the trunk, and there's a dead cat inside.

The cop says, "Did you know there's a dead cat in your trunk?"

Schrödinger says, "Well, there is now."

*brief pause so you can all stop chortling*

The indeterminate nature of reality at the smallest scales always tends to make people shake their head in wonderment at how completely weird the universe is, if they don't simply disbelieve it entirely.  The Uncertainty Principle, peculiar as it sounds, is a fact.  It isn't a limitation of our measurement technique, as if you were trying to find the size of something small and had a poorly-marked ruler, so you could get a more accurate number if you found a better one.  This is something fundamental and built-in about reality.  There are pairs of measurements for which precision is mutually exclusive, such as velocity and position -- the more accurate your information is about one of them, the less you can even theoretically know about the other.

Likewise, the collapse of the wave function, which gave rise to the story of the famous (but ill-fated) cat, is an equally counterintuitive part of how reality is put together.  Outcomes of purely physical questions -- such as where a particular electron is at a given time -- are probabilities, and only become certainties when you measure them.  Again, this isn't a problem with measurement; it's not that the electron really is in a specific location, and you just don't know for sure where until you look.  Before you measure it, the electron's reality is that it's a spread-out field of probabilities.  Something about interacting with it using a measuring device makes that field of probabilities collapse into a specific location -- and no one knows exactly why.

But if you want your mind blown further -- last week in a paper in Physical Review Letters we found out how long it takes.

It turns out the wave function collapse isn't instantaneous.  In "Tracking the Dynamics of an Ideal Quantum Measurement," by a team led by Fabian Pokorny of Stockholm University, the researchers describe a set of experiments involving "nudging" a strontium atom with a laser to induce the electrons to switch orbits (i.e. making them assume a particular energy, which is one of those quantum-indeterminate things like position).  The fidelity of the measurement goes down to the millionths of a second, so the scientists were able to keep track of what happened in fantastically short time intervals.

And the more they homed in on what the electron was doing, the fuzzier things got.  The theory is that as you get down on those scales, time itself becomes blurred -- so the shorter the time interval, the less certain you are about when exactly something happened.

"People assume that time is a strict progression from cause to effect, but actually, from a non-linear non-subjective viewpoint, it's more of a big ball of wibbly-wobbly timey-wimey... stuff." -- The Tenth Doctor, "Blink"

I don't know about you, but I thought I had kinda sorta wrapped my brain around the quantum indeterminacy of position thing, but this just blew my mind all over again.  Even time is fuzzy?  I shouldn't be surprised; for something so damn familiar, time itself is really poorly understood.  With all of the spatial dimensions, you can move any direction you want; why is time one-way?  It's been explained using the Second Law of Thermodynamics, looking at ordered states and disordered states -- the explanation goes something like this:

Start with an ordered state, such as a hundred pennies all heads-up.  Give them a quick shake.  A few will flip, but not many.  Now you might have 83 heads and 17 tails.  There are a great many possible ways you could have 83 heads and 17 tails as long as you don't care which pennies are which.  Another shake, and it might be 74/26, a configuration that there are even more possibilities for.  And so on.  Since at each turn there are a huge number of possible disordered states and a smaller number of ordered ones, each time you perturb the system, you are much more likely to decrease orderliness than to increase it.  You might shake a 50/50 distribution of pennies and end up with all heads -- but it's so fantastically unlikely that the probability might as well be zero.  This push toward disorder gives an arrow to the direction of time.

Well, that's all well and good, but there's also the problem I wrote about last week, about physical processes being symmetrical -- there are a great many of them that are completely time-reversible.  Consider, for example, watching a ten-second clip of a single billiard ball bouncing off the side of a pool table.  Could you tell if you were watching the clip backward or forwards?  It's unlikely.  Such interactions look as sensible physically in real time or time-reversed.

So what time actually is, and why there's an arrow of time, is still a mystery.  Because we certainly feel the passage of time, don't we?  And not from any probabilistic perception of "well, I guess it's more likely time's flowing this way today because things have gotten more disorderly."  It feels completely real -- and completely fixed and invariable.

As Einstein put it, "The distinction between past, present, and future is an illusion, but it is a stubbornly persistent one."

Anyhow, that's our bizarre scientific discovery of the day.  But I better get this post finished up.  Time's a wasting.

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This week's Skeptophilia book recommendation of the week is a classic -- Martin Gardner's wonderful Did Adam and Eve Have Navels?

Gardner was a polymath of stupendous proportions, a mathematician, skeptic, and long-time writer of Scientific American's monthly feature "Mathematical Games."  He gained a wonderful reputation not only as a puzzle-maker but as a debunker of pseudoscience, and in this week's book he takes on some deserving targets -- numerology, UFOs, "alternative medicine," reflexology, and a host of others.

Gardner's prose is light, lucid, and often funny, but he skewers charlatans with the sharpness of a rapier.  His book is a must-read for anyone who wants to work toward a cure for gullibility -- a cure that is desperately needed these days.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

Breaking the world in two

It's no revelation to regular readers of Skeptophilia that I'm fascinated with quantum physics.

In fact, some years ago I was in the car with my younger son, then about 17, and we were discussing the difference between the Many-Worlds and the Copenhagen Interpretation of the collapse of the wave function (as one does), and he said something that led to my writing my time-travel novel, Lock & Key: "What if there was a place that kept track of all the possible outcomes, for every decision anyone makes?"

And thus was born the Library of Possibilities, and its foul-mouthed, Kurt-Cobain-worshiping Head Librarian, Archibald Fischer.

The Many-Worlds Interpretation -- which, put simply, surmises that at every point where any decision could have gone two or more ways, the universe splits -- has always fascinated me, but at the same point, it does seem to fall into Wolfgang Pauli's category of "not even wrong."  It's not falsifiable, because at every bifurcation, the two universes become effectively walled off from each other, so we wouldn't be able to prove or disprove the claim either way.  (This hasn't stopped fiction writers like me from capitalizing on the possibility of jumping from one to the other; this trope has been the basis of dozens of plot lines in Star Trek alone, where Geordi LaForge was constantly having to rescue crew members who fell through a rip in the space-time continuum.)

So it was with great curiosity that I read an article written by physicist Sean Carroll that appeared in Literary Hub last week, that looks at the possible outcome in our own universe if Many-Worlds turns out to be true -- and a way to use quantum mechanics as a basis for making choices.

[Image is in the Public Domain]

Carroll writes:

[Keep in mind] the importance of treating individuals on different branches of the wave function as distinct persons, even if they descended from the same individual in the past.  There is an important asymmetry between how we think about “our future” versus “our past” in Many-Worlds, which ultimately can be attributed to the low-entropy condition of our early universe. 

Any one individual can trace their lives backward in a unique person, but going forward in time we will branch into multiple people.  There is not one future self that is picked out as "really you," and it’s equally true that there is no one person constituted by all of those future individuals.  They are separate, as much as identical twins are distinct people, despite descending from a single zygote. 

We might care about what happens to the versions of ourselves who live on other branches, but it’s not sensible to think of them as "us."

Carrol's point is whether, if you buy Many-Worlds, we should concern ourselves with the consequences of our decisions.  After all, if every possible outcome happens in some universe somewhere -- if everything that can happen, will happen -- then the net result of our decision-making is exactly zero.  If in this branch, you make the decision to rob a bank, and in the other, you decide not to, this is precisely the same outcome as if you decided not to in this branch and your counterpart decided to go through with the robbery in the other one.  But as Carroll points out, while it doesn't make any overall difference if you take into account every possible universe, that's a perspective none of us actually have.  Your decision in this branch does matter to you (well, at least I hope it does), and it certainly has consequences for your future in the universe you inhabit -- as well as restricting what choices are available to you for later decision-making.

 If you'd like to play a little with the idea of Many-Worlds, you can turn your decision-making over to a purely quantum process via an app for iPhones called "Universe Splitter."  You ask the app a two-option question -- Carroll's example is, "Should I have pepperoni or sausage on my pizza tonight?" -- and the app sends a signal to a physics lab in Switzerland, where a photon is sent through a beam-splitter with detectors on either side.  If the photon goes to the left, you're told to go with option 1 (pepperoni), and if to the right, option 2 (sausage).  So here, as in the famous Schrödinger's Cat thought experiment, the outcome is decided by the actual collapse of an actual wave function, and if you buy Many-Worlds, you've now chopped the universe in two because of your choice of pizza toppings.

What I wonder about, though, is that after you get the results, the decision-making isn't over; you've just added one more step.  Once you get the results, you have to decide whether or not to abide by them, so once again you've split the universe (into "abide by the decision" and "don't" branches).  How many of us have put a decision up to a flip of the coin, then when the results come in, think, "That's not the outcome I wanted" and flip the coin again?  What's always bothered me about Many-Worlds is that it's an embarrassment of riches.  We're constantly engaging in situations that could go one of two or more ways, so within moments, the number of possible outcomes in the entire universe becomes essentially infinite.  Physicists tend to be (rightly) suspicious of infinities, and this by itself makes me dubious about Many-Worlds.  (I deliberately glossed over this point in Lock & Key, and implied that all human choices could be catalogued in a library -- albeit a very, very large one.  That may be the single biggest whopper I've told in any of my fiction, even though as a speculative fiction writer my stock in trade is playing fast-and-loose with the universe as it is.)

Carroll is fully aware of how bizarre the outcome of Many-Worlds is, even though (by my understanding) he appears to be in favor of that interpretation over the seemingly-arbitrary Copenhagen Interpretation.  He says -- and this quote seems as fitting a place to stop as any:

Even for the most battle-hardened quantum physicist, one must admit that this sounds ludicrous.  But it’s the most straightforward reading of our best understanding of quantum mechanics.   

The question naturally arises: What should we do about it?  If the real world is truly this radically different from the world of our everyday experience, does this have any implications for how we live our lives?

Largely—no. To each individual on some branch of the wave function, life goes on just as if they lived in a single world with truly stochastic quantum events...  As counterintuitive as Many-Worlds might seem, at the end of the day it doesn’t really change how we should go through our lives.

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This week's Skeptophilia book recommendation is by the team of Mark Carwardine and the brilliant author of The Hitchhiker's Guide to the Galaxy, the late Douglas Adams.  Called Last Chance to See, it's about a round-the-world trip the two took to see the last populations of some of the world's most severely endangered animals, including the Rodrigues Fruit Bat, the Mountain Gorilla, the Aye-Aye, and the Komodo Dragon.  It's fascinating, entertaining, and sad, as Adams and Carwardine take an unflinching look at the devastation being wrought on the world's ecosystems by humans.

But it should be required reading for anyone interested in ecology, the environment, and the animal kingdom. Lucid, often funny, always eye-opening, Last Chance to See will give you a lens into the plight of some of the world's rarest species -- before they're gone forever.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

The library of possibilities

In the brilliant Doctor Who episode "Turn Left," the Doctor's companion Donna Noble finds out that a single decision she made on a single day -- whether to turn right or left at an intersection -- creates two possible futures, one of them absolutely horrific.

It's a common trope in science fiction (although in my opinion, it's seldom been done as well, nor as poignantly, as in "Turn Left"), to look at how our futures could have been significantly different than they are.  I even riffed on this in one of my own novels -- Lock & Key -- in which there are not only multiple possible outcomes for each decision, there's a library (and a remarkably grumpy Head Librarian) that keeps track of not only what has happened, but what could have happened.  For every human being who ever existed, or who ever might have existed.

If you want to know how I handled the idea, you'll just have to read the book.

In reality, of course, the number of possible outcomes for even a simple series of choices increases exponentially with each successive decision, so in any realistic situation the possibilities are about as close to infinite as you can get.  Which makes a paper that came out in Nature last week even more extraordinary.

In order to see how amazing it is, a brief lesson in quantum mechanics for the non-physics-types in the studio audience.

One of the basic concepts in quantum physics is superposition: any measurable property of a wave (or subatomic particle) exists in multiple states at the same time.  The distribution of these states -- more specifically, the probability that the particle is in a specific state -- can be described by its wave function.  And the completely counterintuitive outcome of this model is that prior to observation, the particle is in all possible states at once, and only drops into a particular one (in a process called "collapsing the wave function") when it's observed.  (Regular readers of Skeptophilia may recall that I did a post on a particular part of this theory, Wigner's paradox, a few weeks ago.)

So that's amazing enough.  Particles and waves exist as a multitude of present possibilities, all at the same time.  But now, a collaboration between physicists at Griffith University (Queensland, Australia) and Nanyang Technological University (Singapore) have gone a step further:

They have developed a prototype device that generates a quantum state embodying all of the particle's future states simultaneously.

 My first thought was, "That can't possibly mean what it sounds like."  But yes, that turns out to be exactly what it means.  "When we think about the future, we are confronted by a vast array of possibilities," said Mile Gu of Nanyang Technological University, who led the study.  "These possibilities grow exponentially as we go deeper into the future. For instance, even if we have only two possibilities to choose from each minute, in less than half an hour there are 14 million possible futures.  In less than a day, the number exceeds the number of atoms in the universe."

So having even a simple system that generates all possible futures at the same time is somewhere beyond amazing, and into the realm of the nearly incomprehensible.

"Our approach is to synthesize a quantum superposition of all possible futures for each bias," said Farzad Ghafari, of Griffith University.  "By interfering these superpositions with each other, we can completely avoid looking at each possible future individually.  In fact, many current artificial intelligence (AI) algorithms learn by seeing how small changes in their behavior can lead to different future outcomes, so our techniques may enable quantum enhanced AIs to learn the effect of their actions much more efficiently."

"The functioning of this device is inspired by the Nobel Laureate Richard Feynman," added Dr Jayne Thompson, a member of the Singapore team.  "When Feynman started studying quantum physics, he realized that when a particle travels from point A to point B, it does not necessarily follow a single path.  Instead, it simultaneously transverses all possible paths connecting the points.  Our work extends this phenomenon and harnesses it for modeling statistical futures."

So I'm sitting here, trying to wrap my brain around the implication of this research.  Quantum indeterminacy indicates that we don't live in a completely deterministic universe; there's always some uncertainty, built into the actual fabric of the universe.  But the idea that we could, even in principle, create a system from which we could analyze all of the possible futures is stunning.

As Maggie Carmichael, the Assistant Librarian in Lock & Key, puts it:

All of our actions, even the smallest ones, make a difference.  Most of us never find out what that difference is.  All choices have consequences, however insignificant they seem at the time.  However, the truth of that statement is only evident here in the Library, where we can see what would have happened if we had acted otherwise.  Without that information, what happens simply… happens.

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This week's Skeptophilia book recommendation is a fun one; Atlas Obscura by Joshua Foer, Dylan Thuras, and Ella Morton.  The book is based upon a website of the same name that looks at curious, beautiful, bizarre, frightening, or fascinating places in the world -- the sorts of off-the-beaten-path destinations that you might pass by without ever knowing they exist.  (Recent entries are an astronomical observatory in Zweibrücken, Germany that has been painted to look like R2-D2; the town of Story, Indiana that is for sale for a cool $3.8 million; and the Michelin-rated kitchen run by Lewis Georgiades -- at the British Antarctic Survey’s Rothera Research Station, which only gets a food delivery once a year.)

This book collects the best of the Atlas Obscura sites, organizes them by continent, and tells you about their history.  It's a must-read for anyone who likes to travel -- preferably before you plan your next vacation.

(If you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!)

The collapse of reality

I can say with some level of confidence that I'm nowhere near smart enough to be a philosopher.  Or, honestly, even to read most philosophical treatises with understanding.

An acquaintance of mine is a Ph.D. in philosophy, and she showed me a bit of her dissertation.  It was a kind gesture, but I read the piece of it she sent me with the same expression my dog gets when I try to explain something to him that's completely beyond his grasp, like why I don't want to play ball when we're in the middle of an ice storm.  You can tell he really wants to understand, that he would if he could, and that he feels bad that it makes no sense to him, but the whole thing only registers enough to trigger the Canine Head-Tilt of Puzzlement.

So with that disclaimer out of the way, I'm going to leap into deep waters surrounding an experiment that was the subject of a paper in arXiv last month that -- according to an article in MIT Technology Review -- shows that there's no such thing as objective reality.

The paper, entitled, "Experimental Rejection of Observer-Independence in the Quantum World," by Massimiliano Proietti, Alexander Pickston, Francesco Graffitti, Peter Barrow, Dmytro Kundys, Cyril Branciard, Martin Ringbauer, and Alessandro Fedrizzi, working at Heriot-Watt University (Edinburgh, Scotland), investigates a little-known conundrum of quantum mechanics called the Wigner's Friend Paradox.  This one adds a new layer onto the famous Schrödinger's Cat Paradox, which seems to imply that something can be in two opposing states at once until someone observes it and "collapses the wave function."

Here's the idea of Wigner's Friend (named after Nobel Prize-winning physicist Eugene Wigner).

Let's say there's a single photon being studied in a laboratory by a colleague of Wigner.  The friend observes the photon, which can be polarized either horizontally or vertically -- Wigner doesn't know which.  The friend does a measurement to find out the direction of polarization of the photon, collapsing its wave function and forcing it into one or the other, and then writes down the results -- but doesn't tell Wigner.

Then Wigner studies the same photon.  What he'll find, goes the theory, is that to Wigner, the photon is still in two superposed states at the same time.  Ergo, Wigner and his friend observe the same real phenomenon, and they come up with different answers about it.

And they're both right.

This seems like some kind of trickery, but it's not.  Reality for Wigner and his friend are demonstrably different.  This opens up a particularly snarly (and bizarre) problem called the "consciousness causes collapse" interpretation of quantum mechanics, and that's where the waters get even deeper.

[Image is in the Public Domain]

In a nutshell, here's the problem.  The collapse of the wave function happens because of interaction with an observer, but what counts as an observer?  Does the observer have to be conscious?  If a photon strikes a rock, with a particular result in terms of interacting with the rock's atoms, is the rock acting an observer?  To physicist Pascual Jordan, this seems to be stretching a point.  "[O]bservations not only disturb what has to be measured, they produce it," Jordan said.  "We compel [a quantum particle] to assume a definite position...  [therefore] we ourselves produce the results of measurements."

Which prompted Einstein himself to respond that the Moon did not cease to exist when we stopped looking at it.

Despite Einstein's scoffing, though, it seems like that's exactly the sort of thing Wigner's Friend suggests.  The Proietti et al. paper is unequivocal that the "observer problem" can't be dismissed by saying that everything, even inanimate matter, could be an observer, because it requires a sentient entity recording the results of the experiment to produce the effect.  The authors write:

The scientific method relies on facts, established through repeated measurements and agreed upon universally, independently of who observed them.  In quantum mechanics, the objectivity of observations is not so clear, most dramatically exposed in Eugene Wigner's eponymous thought experiment where two observers can experience fundamentally different realities.  While observer-independence has long remained inaccessible to empirical investigation, recent no-go-theorems construct an extended Wigner's friend scenario with four entangled observers that allows us to put it to the test.  In a state-of-the-art 6-photon experiment, we here realise this extended Wigner's friend scenario, experimentally violating the associated Bell-type inequality by 5 standard deviations.  This result lends considerable strength to interpretations of quantum theory already set in an observer-dependent framework and demands for revision of those which are not.

The MIT Technology Review article outlines how earthshattering this result is.  The author writes:

[T]here are other assumptions too.  One is that observers have the freedom to make whatever observations they want.  And another is that the choices one observer makes do not influence the choices other observers make—an assumption that physicists call locality. 

If there is an objective reality that everyone can agree on, then these assumptions all hold. 

But Proietti and co.’s result suggests that objective reality does not exist.  In other words, the experiment suggests that one or more of the assumptions—the idea that there is a reality we can agree on, the idea that we have freedom of choice, or the idea of locality—must be wrong.

This is the point where my brain simply rebelled.  I've always considered myself a staunch materialist, although (as I said before) I'm well aware both of the fact that there are philosophical arguments to the contrary and that most of them are way beyond my mind to comprehend.  But I've been able to effectively ignore those arguments because science -- my touchstone for reality -- has always seemed to me to support a materialist view.  This table, this desk, this coffee cup all have a realness independent of me, and they would be there substantially unchanged if I weren't looking, or even if I ceased to exist.

But the truth is, as usual, more complex than that.  The hard-edged materialism I've always found so self-evident might not just be arguable, but simply wrong from a scientific basis.  Perhaps our consciousness creates reality -- a view espoused by mystics, and typically rejected by your stubborn science-types (like myself).

I don't know if I'm quite ready to jump there yet.  As the MIT Technology Review article said, it may be there are loopholes in the Wigner's Friend experiment that haven't been uncovered yet.  But one by one those options are being eliminated, with the result that we materialists might be forced to reconsider, if not completely overturn, our view of the world.

All of which makes me feel like I want to hide under my blanket until it all goes away.  Or maybe just play ball with my dog, ice storm be damned.

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This week's Skeptophilia book recommendation is an entertaining one -- Bad Astronomy by astronomer and blogger Phil Plait.  Covering everything from Moon landing "hoax" claims to astrology, Plait takes a look at how credulity and wishful thinking have given rise to loony ideas about the universe we live in, and how those ideas simply refuse to die.

Along the way, Plait makes sure to teach some good astronomy, explaining why you can't hear sounds in space, why stars twinkle but planets don't, and how we've used indirect evidence to create a persuasive explanation for how the universe began.  His lucid style is both informative and entertaining, and although you'll sometimes laugh at how goofy the human race can be, you'll come away impressed by how much we've figured out.

[If you purchase the book from Amazon using the image/link below, part of the proceeds goes to supporting Skeptophilia!]