Reversing the arrow

In my short story "Retrograde," the main character, Eli, meets a woman who makes the bizarre claim that she experiences time running backwards.

She's not like Benjamin Button, who ages in reverse; she experiences everything in reverse.  But from our perspective, nothing seems amiss.  From hers, though... she remembers future events and not past ones:

Hannah gave him a long, steady look.  "All I can say is that we see the same things.  For me, the film runs backwards, that’s all.  Other than that, there’s no difference.  There’s nothing I can do to change the way things unfold, same as with you."

"That’s why you were crying when I came in.  Because of something that for you, had already happened?  What was it?"

She shook her head.  "I shouldn’t answer that, Eli."

"It’s me, isn’t it?  For me, I was just meeting you for the first time.  For you, it was the last time you’d ever see me."  I winced, and rubbed my eyes with the heel of my hand.  "Jesus, I’m starting to believe you.  But that’s it, right?"

Hannah didn’t answer for a moment.  "The thing is—you know, you start looking at things as inevitable.  Like you’re in some sort of film.  The actors seem to have freedom.  They seem to have will, but in reality the whole thing is scrolling by and what’s going to happen is only what’s already written in the script.  You could, if you wanted to, start at the end and run the film backwards.  Same stuff, different direction.  No real difference except for the arrow of time."

Einstein's General Theory of Relativity shows that space and time are inextricably linked -- spacetime -- but doesn't answer the perplexing question of why we can move in any direction through space, but only one direction through time.  You can alter the rate of time's passage, at least relative to some other reference frame, by changing your velocity; but unlike what the characters in "Retrograde" experience, the arrow always points the same way.  

This becomes odder still when you consider that in just about all physical processes, there is no inherent arrow of time.  Look at a video clip of a pool ball bouncing off the side bumper, then run it backwards -- it'd be damn hard to tell which was the actual, forward-running clip.

Hard -- but not impossible.  The one physical law that has an inherent arrow of time is the Second Law of Thermodynamics.  If the clip was long enough, or your measurement devices sensitive enough, you could tell which was the forward clip because in that one, the pool ball would be slowing down from dissipation of its kinetic energy in the form of friction with the table surface.  Likewise, water doesn't unspill, glasses unbreak, snowbanks un-avalanche, reassembling in pristine smoothness on the mountainside.  But why this impels a universal forward-moving arrow of time -- and more personally, why it makes us remember the past and not the future -- is still an unanswered question.

"The arrow of time is only an illusion," Einstein quipped, "but it is a remarkably persistent one."

Two recent papers have shed some light on this strange conundrum.  In the first, a team led by Andrea Rocco of Surrey University looked how the equations of the Second Law work on the quantum level, and found something intriguing; introducing the Second Law into the quantum model generated two arrows of time, one pointing into the past and one pointing into the future.  But no matter which time path is taken, entropy still increases as you go down it.

"You’d still see the milk spilling on the table, but your clock would go the other way around," Rocco said.  "In this way, entropy still increases, but it increases toward the past instead of the future.  The milk doesn’t flow back into the glass, which the Second Law of Thermodynamics forbids, but it flows out of the glass in the direction of the past.  Regardless of whether time’s arrow shoots toward the future or past from a given moment, entropy will still dissipate in that given direction."

In the second, from Lorenzo Gavassino of Vanderbilt University et al., the researchers were investigating the mathematics of "closed time-like loops" -- i.e., time travel into the past, followed by a return to your starting point.  And what they found was that once again, the Second Law gets in the way of anything wibbly-wobbly.

Gavassino's model shows that on a closed time-like loop, entropy must peak somewhere along the loop -- so along some part of the loop, entropy has to decrease to return it to where it was when the voyage began.  The equations then imply that one of two things must be true.  Either:

1. Time travel into the past is fundamentally impossible, because it would require entropy to backpedal; or
2. If overall entropy can decrease somewhere along the path, it would undo everything that had happened along the entropy-increasing part of the loop, including your own memories.  So you could time travel, but you wouldn't remember anything about it (including that it had ever happened).

"Any memory that is collected along the closed time-like curve," Gavassino said, "will be erased before the end of the loop."

So that's no fun at all.  Lieutenant Commander Geordi LaForge would like to have a word with you, Dr. Gavassino.

Anyhow, that's today's excursion into one of the weirdest parts of physics.  Looks like the Second Law of Thermodynamics is still strictly enforced in all jurisdictions.  Time might be able to run backwards, but you'd never know because (1) entropy will still increase in that direction, and (2) any loop you might take will result in your remembering nothing about the trip.  So I guess we're still stuck with clocks running forwards -- and having to wait to find out what's going to happen in the future at a rate of one minute per minute.

****************************************

Dreaming the past

My novel In the Midst of Lions opens with a character named Mary Hansard -- an ordinary forty-something high school physics teacher -- suddenly realizing she can see the future.

More than that, really; she now has no reliable way of telling the future from the past.  She "remembers" both of them, and if she has no external context by which to decide, she can't tell if what's in her mind occurred in the past or will occur in the future.  Eventually, she realizes that the division of the passage of time she'd always considered real and inviolable has changed.  Instead of past, present, and future, there are now only two divisions: present and not-present.  Here's how she comes to see things:

In the past two months, it felt like the universe had changed shape.  The linear slow march of time was clean gone, and what was left was a block that was unalterable, the people and events in it frozen in place like butterflies in amber.  Her own position in it had become as observer rather than participant.  She could see a wedge of the block, extending back into her distant past and forward into her all-too-short future.  Anything outside that wedge was invisible...  She found that it completely dissolved her anxiety about what might happen next.  Being not-present, the future couldn’t hurt her.  If pain lay ahead of her, it was as removed from her as her memories of a broken arm when she was twelve.  Neither one had any impact on the present as it slowly glided along, a moving flashlight beam following her footsteps through the wrecked cityscape.

 I found myself thinking about Mary and her peculiar forwards-and-backwards perception while I was reading physicist Sean Carroll's wonderful and mind-blowing book From Eternity to Here: A Quest for the Ultimate Theory of Time, which looks at the puzzling conundrum of what physicists call time's arrow -- why, when virtually all physical laws are time-reversible, there is a clear directionality to our perceptions of the universe.  A classic example is the motion of billiard balls on a table.  Each ball's individual motion is completely time-reversible (at least if you discount friction with the table); if you filmed a ball rolling and bouncing off a bumper, then ran the recording backwards, it would be impossible to tell which was the original video and which was the reversed one.  The laws of motion make no differentiation between time running forward and time running backward.

But.

If you played a video of the initial break of the balls at the beginning of the game, then ran the recording backwards -- showing the balls rolling around and after a moment, assembling themselves back into a perfect triangle -- it would be blatantly obvious which was the reversed video.  The difference, Carroll explains, is entropy, which is a measure of the number of possible ways a system can exist and be indistinguishable on the macro level.  What I mean by this is that the racked balls are in a low-entropy state; there aren't that many ways you can assemble fifteen balls into a perfect equilateral triangle.  On the other hand, after the break, with the balls scattered around the table seemingly at random -- there are nearly an infinite number of ways you can have the balls arranged that would be more or less indistinguishable, in the sense that any of them would be equally likely to occur following the break.  Given photographs of thousands of different positions, not even Commander Data could determine which one was the pic taken immediately after the balls stopped moving.

Sure, it's possible you could get all the balls rolling in such a way that they would come to rest reassembled into a perfect triangle.  It's just extremely unlikely.  The increase in entropy, it seems, is based on what will probably happen.  There are so many high-entropy states and so few low-entropy states that if you start with a low-entropy arrangement, the chances are it will evolve over time into a high-entropy one.  The result is that it is (very) strongly statistically favored that entropy increases over time.  

The Arrow of Time by artist benpva16 [Image licensed under the Creative Commons Creative Commons BY-NC-ND 3.0 license: creativecommons.org/licenses/b…]

The part of the book that I am still trying to parse is chapter nine, "Information and Life," where he ties the physical arrow of time (an example of which I described above) with the psychological arrow of time.  Why can't we all do what Mary Hansard can do -- see the past and future both -- if the only thing that keeps us knowing which way is forward and which way is backward is the probability of a state's evolution?  After all, there are plenty of cases where entropy can locally go down; a seed growing into a tree, for example.  (This only occurs because of a constant input of energy; contrary to what creationists would have you believe, the Second Law of Thermodynamics doesn't disprove evolution, because living things are open systems and require an energy source.  Turn off the Sun, and entropy would increase fast.)

So if entropy actually explains the psychological arrow of time, why can I remember events where entropy went down -- such as yesterday, when I took a lump of clay and fashioned it into a sculpture?

Carroll's explanation kind of made my mind blow up.  He says that our memories themselves aren't real reflections of the past; they're a state of objects in our environment and neural firings in our brain in the present that we then assemble into a picture of what we think the past was, based on our assumption that entropy was lower in the past than it is now.  He writes:

So let's imagine you have in your possession something you think of as a reliable record of the past: for example, a photograph taken of your tenth birthday party.  You might say to yourself, "I can be confident that I was wearing a red shirt at my tenth birthday party, because this photograph of that event shows me wearing a red shirt."...

[Is] the present macrostate including the photo... enough to conclude with confidence that we were really wearing a red shirt at our tenth birthday party?

Not even close.  We tend to think that [it is], without really worrying about the details too much as we get through our lives.  Roughly speaking, we figure that a photograph like that is a highly specific arrangement of its constituent molecules.  (Likewise for a memory in our brain of the same event.)  It's not as if those molecules are just going to randomly assemble themselves into the form of that particular photo -- that's astronomically unlikely.  If, however, there really was an event in the past corresponding to the image portrayed in the photo, and someone was there with a camera, then the existence of the photo becomes relatively likely.  It's therefore very reasonable to conclude that the birthday party really did happen in the way seen in the photo.

All of those statements are reasonable, but the problem is that they are not nearly enough to justify the final conclusion...  Yes, the photograph is a very specific and unlikely arrangement of molecules.  However, the story we are telling to "explain" it -- an elaborate reconstruction of the past, involving birthday parties and cameras and photographs surviving essentially undisturbed to the present day -- is even less likely than the photo all by itself...

Think of it this way: You would never think to appeal to some elaborate story in the future to explain the existence of a particular artifact in the present.  If we ask about the future of our birthday photo, we might have some plans to frame it or whatnot, but we'll have to admit to a great deal of uncertainty -- we could lose it, it could fall into a puddle and decay, or it could burn in a fire.  Those are all perfectly plausible extrapolations of the present state into the future, even with the specific anchor point provided by the photo here in the present.  So why are we so confident about what the photo implies concerning the past?

The answer, he says, is that we're relying on probability and the likelihood that the past had lower entropy -- in other words, that the photo didn't come from some random collision of molecules, just as our surmise about the billiard balls' past came from the fact that a perfect triangular arrangement is way less likely than a random one.  All we have, Carroll says, is our knowledge of the present; everything else is an inference.  In every present moment, our reconstruction of the past is a dream, pieced together using whatever we're experiencing at the time.

So maybe we're not as different from Mary Hansard, with her moving flashlight beam gliding along and spotlighting the present, as I'd thought.

Mind = blown.

I'm still not completely convinced I'm understanding all the subtleties in Carroll's arguments, but I get enough of it that I've been thinking about it ever since I put the book down.  But in any case, I'd better wrap this up, because...

... I'm running short on time.

****************************************

Timey-wimey light

I don't always need to understand things to appreciate them.

In fact, there's a part of me that likes having my mind blown.  I find it reassuring that the universe is way bigger and more complex than I am, and the fact that I actually can parse a bit of it with my little tiny mind is astonishing and cool.  How could it possibly be surprising that there's so much more out there than the fragment of it I can comprehend?

This explains my love for twisty, complicated fiction, in which you're not handed all the answers and everything doesn't get wrapped up with a neat bow at the end.  It's why I thoroughly enjoyed the last season of Doctor Who, the six-part story arc called "Flux."  Apparently it pissed a lot of fans off because it had a quirky, complicated plot that left a bunch of loose ends, but I loved that.  (I'm also kind of in love with Jodie Whittaker's Thirteenth Doctor, but that's another matter.)

I don't feel like I need all the answers.  I'm not only fine with having to piece together what exactly happened to whom, but I'm okay that sometimes I don't know.  You just have to accept that even with all the information right there in front of you, it's still not enough to figure everything out.

Because, after all, that's how the universe itself is.

[Nota bene: Please don't @ me about how much you hated Flux, or how I'm crediting Doctor Who showrunner Chris Chibnall with way too much cleverness by comparing his work to the very nature of the universe.  For one thing, you're not going to change my mind.  For another, I can't be arsed to argue about a matter of taste.  Thanks.]

In any case, back to actual science.  That sense of reality being so weird and complicated that it's beyond my grasp is why I keep coming back to the topic of quantum physics.  It is so bizarrely counterintuitive that a lot of laypeople hear about it, scoff, and say, "Okay, that can't be real."  The problem with the scoffers is that although sometimes we're not even sure what the predictions of quantum mechanics mean, they are superbly accurate.  It's one of the most thoroughly tested scientific models in existence, and it has passed every test.  There are measurements made using the quantum model that have been demonstrated to align with the predictions to the tenth decimal place.

That's a level of accuracy you find almost nowhere else in science.

The reason all this wild stuff comes up is because of a pair of papers (both still in peer review) that claim to have demonstrated something damn near incomprehensible -- the researchers say they have successfully split a photon and then triggered half of it to move backwards in time.

One of the biggest mysteries in physics is the question of the "arrow of time," a conundrum about which I wrote in some detail earlier this year.  The gist of the problem -- and I refer you to the post I linked if you want more information -- is that the vast majority of the equations of physics are time-reversible.  They work equally well backwards and forwards.  A simple example is that if you drop a ball with zero initial velocity, it will reach a speed of 9.8 meters per second after one second; if you toss a ball upward with an initial velocity of 9.8 meters per second, after one second it will have decelerated to a velocity of zero.  If you had a film clip of the two trajectories, the first one would look exactly like the second one running backwards, and vice versa; the physics works the same forwards as in reverse.

The question, then, is why is this so different from our experience?  We remember the past and don't know the future.  The physicists tell us that time is reversible, but it sure as hell seems irreversible to us.  If you see a ball falling, you don't think, "Hey, you know, that could be a ball thrown upward with time running backwards."  (Well, I do sometimes, but most people don't.)  The whole thing bothered Einstein no end.  "The distinction between past, present, and future," he said, "is only an illusion, albeit a stubbornly persistent one."

This skew between our day-to-day experience and what the equations of physics describe is why the recent papers are so fascinating.  What the researchers did was to take a photon, split it, and allow the two halves to travel through a crystal.  During its travels, one half had its polarity reversed.  When the two pieces were recombined, it produced an interference pattern -- a pattern of light and dark stripes -- only possible, the physicists say, if the reversed-polarity photon had actually been traveling backwards in time as it traveled forwards in space.

The scientists write:

In the macroscopic world, time is intrinsically asymmetric, flowing in a specific direction, from past to future.  However, the same is not necessarily true for quantum systems, as some quantum processes produce valid quantum evolutions under time reversal.  Supposing that such processes can be probed in both time directions, we can also consider quantum processes probed in a coherent superposition of forwards and backwards time directions.  This yields a broader class of quantum processes than the ones considered so far in the literature, including those with indefinite causal order.  In this work, we demonstrate for the first time an operation belonging to this new class: the quantum time flip.

This takes wibbly-wobbly-timey-wimey to a whole new level.

Do I really understand what happened here on a technical level?  Hell no.  But whatever it is, it's cool.  It shows us that our intuition about how things work is wildly and fundamentally incomplete.  And I, for one, love that.  It's amazing that not only are there things out there in the universe that are bafflingly weird, we're actually making some inroads into figuring them out.

To quote the eminent physicist Richard Feynman, "I can live with doubt and uncertainty and not knowing.  I think it's much more interesting to live not knowing than to have answers which might be wrong.  I have approximate answers and possible beliefs and different degrees of certainty about different things, but I'm not absolutely sure about anything."

To which I can only say: precisely.  (Thanks to the wonderful Facebook pages Thinking is Power and Mensa Saskatchewan for throwing this quote my way -- if you're on Facebook, you should immediately follow them.  They post amazing stuff like this every day.)

I'm afraid I am, and will always be, a dilettante.  There are only a handful of subjects about which I feel any degree of confidence in my depth of comprehension.  But that's okay.  I make up for my lack of specialization by being eternally inquisitive, and honestly, I think that's more fun anyhow.

 Three hundreds years ago, we didn't know atoms existed.  It was only in the early twentieth century that we figured out their structure, and that they aren't the little solid unbreakable spheres we thought they were.  (That concept is still locked into the word "atom" -- it comes from a Greek word meaning "can't be cut.")  Since then, we've delved deeper and deeper into the weird world of the very small, and what we're finding boggles the mind.  My intuition is that if you think it's gotten as strange as it can get, you haven't seen nothin' yet.

I, for one, can't wait.

****************************************

The stubbornly persistent illusion

I was driving through Ithaca, New York a while back, and came to a stoplight, and the car in front of me had a bumper sticker that said, "Time is that without which everything would happen at once."

I laughed, but I kept thinking about it, because in one sentence it highlights one of the most persistent mysteries of physics: why we perceive a flow of time.  The problem is, just about all of the laws of physics, from quantum mechanics to the General Theory of Relativity, are time-reversible; they work equally well in forward as in reverse.  Put another way, most physical processes look the same both ways.  If I were to show you a short video clip of two billiard balls colliding on a pool table, then the same clip backwards, it would be hard to tell which was which.  The Laws of Conservation of Momentum and Conservation of Energy that describe the results of the collision work in either direction.

There are exceptions, though.  The Second Law of Thermodynamics is the most commonly-cited one: closed systems always increase in entropy.  It's why when I put sugar in my coffee in the morning and stir it, the sugar spreads through the whole cup.  If I were to give it one more stir and all the sugar molecules were to come back together as crystals and settle out on the bottom, I'd be mighty surprised.  I might even wonder if someone had spiked the sugar bowl with something other than sugar.

In fact, that's why I had to specify a "short clip" in the billiard ball example.  There is a time-irreversible aspect of such classical physics; as the balls roll across the table, they lose momentum, because a little of the kinetic energy of their motion leaks away as thermal energy due to friction with the surface.  When they collide, a little more is lost because of the sound of the balls striking each other, the (slight) physical deformation they undergo, and so on.  So if you had a sensitive enough camera, or a long enough clip, you could tell which was the forward and which the reverse clip, because the sum of the kinetic energies of the balls in the forward clip would be (slightly) greater before the collision than after it.

But I am hard-pressed to see why that creates a sense of the flow of time.  It can't be solely from our awareness of a movement toward disorder.  When there's an energy input, you can generate a decrease in entropy; it's what happens when a single-celled zygote develops into a complex embryo, for example.  There's nothing in the Second Law that prevents increasing complexity in an open system.  But we don't see those situations as somehow running in reverse; entropy increase by itself doesn't generate anything more than expected set of behaviors of certain systems.  How that could affect how time is perceived by our brains is beyond me.

The problem of time's arrow is one of long standing.  Einstein himself recognized the seeming paradox; he wrote, "The distinction between past, present, and future is only a stubbornly persistent illusion."  "Persistent" is an apt word; more than sixty years after the great man's death, there was an entire conference on the nature of time, which resolved very little but giving dozens of physicists the chance to defend their own views, and in the end convinced no one.

It was, you might say, a waste of time.  Whatever that means.

One of the most bizarre ideas about the nature of time is the one that comes out of the Special Theory of Relativity, and was the reason Einstein made the comment he did: the block universe.  I first ran into the block universe model not from Einstein but from physicist Brian Greene's phenomenal four-part documentary The Fabric of the Cosmos, and it goes something like this.  (I will append my usual caveat that despite my bachelor's degree in physics, I really am a layperson, and if any physicists read this and pick up any mistakes, I would very much appreciate it if they'd let me know so I can correct them.)

One of the most mind-bending things about the Special Theory is that it does away with simultaneity being a fixed, absolute, universal phenomenon.  If we observe two events happening at exactly the same time, our automatic assumption is that anyone else, anywhere in the universe, would also observe them as simultaneous.  Why would we not?  But the Special Theory shows conclusively that your perception of the order of events is dependent upon your frame of reference.  If two individuals are in different reference frames (i.e. moving at different velocities), and one sees the two events as simultaneous, the other will see them as sequential.  (The effect is tiny unless the difference in velocities is very large; that's why we don't experience this under ordinary circumstances.)

This means that past, present, and future depend on what frame of reference you're in.  Something that is in the future for me might be in the past for you.  This can be conceptualized by looking at space-time as being shaped like a loaf of bread; the long axis is time, the other two represent space.  (We've lost a dimension, but the analogy still works.)  The angle you are allowed to slice into the loaf is determined by your velocity; if you and two friends are moving at different velocities, your slice and theirs are cut at different angles.  Here's a picture of what happens -- to make it even more visualizable, all three spatial dimensions are reduced to one (the x axis) and the slice of time perceived moves along the other (the y axis).  A, B, and C are three events, and the question is -- what order do they occur in?

[Image licensed under the Creative Commons User:Acdx, Relativity of Simultaneity Animation, CC BY-SA 4.0]

As you can see, it depends.  If you are taking your own velocity as zero, all three seem to be simultaneous.  But change the velocity -- the velocities are shown at the bottom of the graph -- and the situation changes.  To an observer moving at a speed of thirty percent of the speed of light relative to you, the order is C -> B -> A.  At a speed of fifty percent of the speed of light in the other direction, the order is A -> B -> C.

So the tempting question -- who is right? what order did the events really occur in? -- is meaningless.

Probably unnecessarily, I'll add that this isn't just wild speculation.  The Special Theory of Relativity has been tested hundreds, probably thousands, of times, and has passed every test to a precision of as many decimal places as you want to calculate.  (A friend of mine says that the papers written about these continuing experiments should contain only one sentence: "Yay!  Einstein wins again!")  Not only has this been confirmed in the lab, the predictions of the Special Theory have a critical real-world application -- without the equations that lead directly to the block universe and the relativity of simultaneity, our GPS systems wouldn't work.  If you want accurate GPS, you have to accept that the universe has some seriously weird features.

So the fact that we remember the past and don't remember the future is still unexplained.  From the standpoint of physics, it seems like past, present, and future are all already there, fixed, trapped in the block like flies in amber.  Our sense of time flowing, however familiar, is the real mystery.

But I'd better wrap this up, because I'm running out of time.

Whatever that means.

**************************************

Retrograde

One thing I haven't done yet on Fiction Friday is to post one of my pieces of fiction.  Seemed a bit ironic, that, so today I'm sharing "Retrograde," a strange short story about time, a chance meeting, and how we all watch the film unwind from our own perspectives.  It's not available anywhere else, so here you have it: an Exclusive Release.  Enjoy!

*************************************

Retrograde

I met Hannah about a month ago.  Of course, she wouldn’t phrase it that way, but maybe there’s no other way to say it and be understood, so let’s just leave it there; I met her about a month ago, the week before Christmas.

It had been an unusually cold December.  Even people who’d been born and raised in Ithaca were complaining.  There were about two feet of ice-crusted snow on the ground, and the sound of the plows growling by became so common that you stopped hearing them.  I was walking up Meadow Street, and as my boots pressed into the snow on the sidewalk, they made that squeaking noise that only happens when the temperature is getting close to zero.

I do this walk most nights, up from the bicycle shop where I work to the Ithaca Bakery to grab a bite to eat, then over two blocks on Cascadilla Street where I rent an upstairs room from an elderly couple.  It’s an okay life but you don’t need to tell me that I’m floating, that I’m slipping through life doing the bare minimum.  My mom tells me that most times I talk to her, but it’s not like I don’t see it myself.  I’ve got a decent brain.  I know I could do okay in college, but right now, I just don’t see a path.  I’d rather work at the bike shop, come home with my food and sit and read or watch TV or mess around online, than go to college and spend lots of money to spin my wheels, you know?

Anyway, I was doing my usual trek on that icy December night.  It was right around the solstice, so it’d been dark since around five o’clock, and by this time it was that kind of dark that seems to be an actual substance, not just an absence of light.  Even the streetlights didn’t help much, just illuminated the flakes of snow that were beginning to fall again.  I passed a guy I often see on that walk – tall middle-aged dude, wearing an old-fashioned felt hat with a feather, always going the other way, carrying a briefcase.  That night he had a thick scarf wrapped around his face, and I could barely hear his voice as he said, “What happened to the goddamn global warming?”

 
“No kidding.” 

“Winter storm warning tonight,” he said.  “Supposed to get another foot and a half by tomorrow noon.  Christ.”

I shook my head.  “Unbelievable,” and then we both went on our way.

[Image licensed under the Creative Commons Mehr News Agency, 23 January 2020, Arak (13), CC BY 4.0]

The Ithaca Bakery was empty except for me.  There never were many people in this late, but it wasn’t usually completely empty.  Probably the winter storm warning kept everyone with any common sense home.

I could hear a couple of folks in the kitchen, bumping around as they cleaned up.  There was only one person behind the counter.  I’d never seen her before, and I knew most of the staff by name.  She’d been looking down when I walked in, her hands holding onto the counter, but then she looked up at me.

She was one of those people who is hard to describe; pretty but not beautiful, medium-length blond hair held back by a clip, oval face, medium height.  Her only real standout feature was her eyes, which were a very pale blue.  An artist might describe them as a chilly blue, an icy blue, but that’s not right; there was no cold in them at all.  They had a fire in them.  I’ve read that the hottest fire, past red hot, and yellow, and white, is blue; and after seeing her eyes, I think I understand that.

And as soon as those eyes met mine, she started crying.

She looked down again, still clutching the counter, her whole body shaking.

“Jesus,” I said.  “What’s wrong?”

She shook her head, kept on crying, and I just stood there, feeling weird and uncomfortable, and glad there were no other people in the Bakery that night.

Finally she just looked up, those pale eyes still flooded with tears, and said, “Eli, I can’t believe it’s already that time.”

I stared at her for a moment, and then said, “Do I know you?”

“Not yet.  But you will.”  She drew a sleeve across her eyes, and attempted a smile.  She finally unclenched one of her hands from the counter edge, and reached it across for me to shake.  “I’m Hannah.” 

“Eli,” I said, even though she apparently already knew that somehow.

“What can I get you tonight?”  She was obviously trying for that cheerful and courteous sound restaurant staff always have, and mostly succeeded.

“Sun-dried tomato bagel, toasted, cream cheese and lox.”

She smiled a little bit, for real now, said, “The usual, then,” and turned away to get me my food.  I put a ten dollar bill on the counter, and pretty soon she came up, handed me my plate, gave me my change.

“Look,” I said, still feeling strange, “you want to talk for a while?”

She shrugged.  “No one’s here tonight, and the place closes soon anyway.  We won’t get many more people in this weather, and if we do, I can just get up and take care of them, right?”

“That’s fine.  We can talk for a little while.”

I went to a table, over in the corner by the window, and she followed me, sat down, and rested her chin in her hands, her elbows on the table.

I looked at her, trying to place where I knew her from, but still drew a blank.  I’ve got a good memory for faces, and I wouldn’t forget those eyes, I knew that.  I was certain I’d never seen this woman before.

“I know you don’t understand now, Eli,” she said.  “It’s so awful for you.  I’m sorry about the way I acted.  Inexcusable, really inexcusable.”

“Are you sure you know me?” I took a bite of my bagel.

She just smiled a little.  “Do you want me to explain?  It won’t make much sense now.  It will later.”  She paused.  “My name is Hannah, by the way.”

“Hannah,” I said.  “I know.  You already told me.  But explain?  Explain what?”

She looked out of the window, at the snow falling faster, hissing against the glass panes.

“I don’t see the world the way others do.”

That was kind of a vague start, I thought.  “None of us see the world the same way.  That doesn't mean your point of view isn't valid.”  I was trying to be helpful, but only ending up sounding like somebody who’s read too much pop psychology.

Her lips tightened, her face looking resolute.   “Okay. I guess I just need to say it straight out.”  She took a deep breath, exhaled slowly.  “What’s the past for you is the future for me,” she said, in a low, intense voice, and then just looked at me, her pale eyes searching mine.

My rational mind said, This chick is crazy, but something about her demeanor seemed so normal that I couldn’t just attribute her odd behavior to her being a nut.  “What’s that supposed to mean?” 

“When you say something is in the past,” she said, patiently, “it hasn’t happened for me yet.  What I remember is what you call the future.  What you call the past I don’t remember, because it hasn’t happened yet.  For me, at least.”

I stared at her, my mouth hanging open a little.  “That’s impossible.  The past is the past.  The future is the future.”

“Not for me.”

“Time passes the same way for everyone.”

She shook her head.  “It’s been this way all of my life.  All the few short weeks of my life.  Time runs backwards for me.”  She gestured at my plate, and smiled a little wryly.  “Can I have a bite of your bagel?  I’m starving.”

I picked up half of the bagel, handed it to her.  “Why did you ask, if for you it’d already happened?  For you, you’d already taken a bite, right?”

“Yes.  But I knew by what you said that it was going to happen, and if I hadn’t asked afterwards, you would have wondered why the hell this strange chick had taken a bite of your dinner without asking.  I learned this stuff the hard way.  I’m beginning to adapt.”

“So you asked to have some of my bagel because for you it had already happened?”

She shrugged.  “I guess from your perspective, that’s the only way you could make sense of it.”

“This doesn’t make any sense.  The clock only runs one way.  No one lives in a world where glasses unbreak, snow falls upward, balls roll uphill.  That’s scientifically impossible, right?”

“I can’t answer that.  All I can say is that we see the same things.  For me, the film runs backwards, that’s all.  Other than that, there’s no difference.  There’s nothing I can do to change the way things unfold, same as with you.”

“That’s why you were crying, when I came in.  Because of something that for you, had already happened?  What was it?”

She shook her head.  “I shouldn’t answer that.”

I thought for a moment.  “It’s me, isn’t it?  For me, I was just meeting you for the first time; for you, it was the last time you’d ever see me.”  I winced, and rubbed my eyes with the heel of my hand.  “Jesus, I’m starting to believe you.  But that’s it, right?”

She didn’t answer for a moment.  “The thing is, you know, you just start looking at things as inevitable.  Like you’re in some sort of film.  The actors seem to have freedom, they seem to have will, but in reality the whole thing is just scrolling by and what’s going to happen is only what’s already written in the script.  You could, if you wanted to, start at the end and run the film backwards.  Same stuff, different direction.  No real difference except for the arrow of time.”

“I guess I’d cry, too.”

The corners of her mouth turned up a little.  “It’s no problem, I can get you another bagel.”

 

Before I could ask her what she was talking about, there was a sudden crash as someone dropped something in the kitchen.  I jumped, and my hand jerked.  The plate with my dinner slid off the table and fell upside down on the floor.

I looked at it, mutely, then at her.  She shrugged and smiled.

“Yeah,” I finally said. “That’d be great.”

She stood up, one eyebrow raised quizzically, and went off to the kitchen.

My mind was spinning.  Was she crazy, or was what she was saying the literal, factual truth?  How could anyone perceive the world in reverse?  If what she was saying was true, someone should be told; it would blow away all of what was known about science.

But then, how could they test it?  As her life unrolled, she would forget more and more, because as our clocks moved forward, hers would be moving backward.  Only at the present moment did our lives touch – for an instant only, and then continued to spin away along their inverted paths.

She returned with the bagel.

“Sun-dried tomato, cream cheese, and lox,” I said.  “You remembered that, at least.”

She just smiled at me, and sat down, then reached across the table, and took my hand.

Then I realized -- no, she didn’t remember.  I'd just told her.  All she did was get what I just told her to get.

Looking across at her, my heart gave a funny little gallop in my chest.  She knew it because it had already happened for her.  It was the past.  She was remembering, not predicting.  And I think that’s the moment when I was convinced that she was telling the truth.

“It’s been three weeks since it all started,” she said, still holding my hand.  “It’s nice to find someone to tell about all this.  You’re the first person I’ve told.”

“Three weeks?  Three weeks since what?”

“My life started three weeks ago.  I don’t really understand how, but there it is.”

“Started?  Started how?  What happened three weeks ago?”

She looked down, her eyes becoming unfocused for a moment, as she searched her… memory?  What else could you call it?  After a moment, she looked up.  “The first thing I remember is a shock.  Like an explosion.  Then I felt wind.  Before I knew what was happening, I was up on a bridge, near Cornell, over that really beautiful gorge, I forget its name.  It was snowing, just like today.  Cold.  I didn’t know where I was, all I knew was that my name was Hannah and I was cold.  And I began to walk, and finally came here, and talked to one of the managers, and he offered me a job.  They let me sleep on a cot in one of the offices in back.  Only till I can get a place, and it was really nice of them to let me.  I honestly don’t know why they agreed.  But three weeks – yes, that’s when it all started.”

“So that means you’ve only got three weeks to live.”

“I suppose that’s the way it would appear, from your perspective.”

“My perspective?” I shouted.   “My perspective is all I have!  You don’t mean to tell me that in three weeks you’re going to die, and there’s nothing you can do about it?”

Hannah shrugged.  “I don’t know any other way to explain it.  It really is all about perspective.”

I leaned back in my chair.  “So you’re telling me that from your point of view, you’re going to get younger and younger, and finally a baby, and then you’ll disappear up into your mother’s uterus, and then you’ll just… cease to be?”

“It’s not so very much weirder than your life seems to me.  Where were you before you were born?  And what will happen to you when you die?”

Well, she got me there, and I didn’t respond for a moment.  “I don’t know,” I finally said.  “I’m not religious.  But even so, I don’t know how you can expect this to make sense to me.”

“Look, you don’t have to be upset on my behalf.  It is what it is.  Maybe we should just stop talking about all these matters of life and death, and the afterlife.  Or beforelife.  Or whatever.”

The snow was falling faster now, beginning to pile up on the older drifts, swirling in curtains against the streetlight.  “I’m not upset,” I said, and I was telling the truth.  I felt completely calm for some reason, despite having spent fifteen minutes in what was the most peculiar conversation I’d ever had.  I ate the last bit of my bagel, and looked into those eyes, those strange, luminous eyes.  “Look, I don’t know.  Do you want to come back to my place?  I know it’s weird to ask, but it might be better than your staying here, alone, and having to be left with… your memories.”

 
She smiled. “I’d like that.”

I held out my hand for her, and she stood.  “Let’s go,” I said.  “I just live a couple of blocks away.”


We didn’t talk any more about time and perspective – just talked about what we liked, talked about the weather.  We each had a beer and sat on the couch for a while, and then went to bed.  I offered her the couch, but she smiled and shook her head, saying that that if the point was for her not to be lonely, the couch was no better than her cot back at the Bakery.  I didn’t argue.

We made love that night, and as I was drifting off to sleep, I wondered what that had been like for her – an explosion, merging into excitement, fading into anticipation, then subsiding into silence.  I hoped that it was good, however she had perceived it.


She stayed with me for three days.  On the morning of the fourth day, I awoke to find a note on the pillow next to me, and that she was gone.  It wasn’t really a surprise, but still, it made my stomach clench when I picked it up.  Time was spooling by, the clock was running; it never stopped, whatever direction it was going.  You couldn’t halt it either way.

The note read:

Eli… 

I know you won’t understand, but this can’t go on indefinitely.  It will make sense to you eventually, I hope.  I hardly know you, and as time passes for you, I will know you less and less, and finally forget you entirely.  It’s better this way. 

Hannah

I looked at the note for a while, then got up, showered, dressed, and headed up to the Bakery.

Hannah was behind the counter.  She looked up at me, and I was greeted by a smile.  I went up to her, stood silent for a moment.

“My name is Eli,” I said.  “I don’t want you to forget that.  Eli.  And for three days, you were important to me, Hannah.”

She smiled again, those odd eyes glittering.  “I won’t forget,” she said, and reached across and touched my hand.

“Don’t forget,” I said.  “Don’t ever forget me.”


And that was all.

I went in to the Bakery a couple of days after that, near closing time, taking my usual route after getting off from work at the bike shop.  Tom, the long-haired, multiply-pierced counterman, greeted me with a grin.

“Hey, Eli,” he said.  “The usual?”

“Yeah,” I said.  He started putting together my dinner.  “Hey, Tom.  What do you think about that girl who works here, Hannah?”

Tom half turned, my bagel in his hand.  He rolled his eyes.  “That chick is wack, and that’s my considered opinion.  Owner said she could live in the back room for a coupla weeks, till she finds a place.  But she’s a strange one.  Nice-looking, though.”

I nodded.  “Yeah.  Pretty strange.  You got that right.”


Then last week, in the Ithaca Journal, the following article appeared on the front page.

Local Woman Killed in Fall from Bridge 

Hannah van Meter, 24, was killed in what police are considering a probable suicide.  On the night of January 17, she fell from the bridge on Stewart Avenue into Fall Creek Gorge.  A witness, whose name has not been released by police, stated that she had been standing for some time, looking down into the gorge, and that he went up and attempted to speak to her.  She seemed disoriented, and would not leave the bridge even though the witness attempted to persuade her to do so.  She threatened to jump if he approached her more closely, he stated.  After five minutes, the witness went to a nearby house to get help, and was walking back up toward the bridge when van Meter jumped or fell over the bridge railing. 

She was the daughter of David and Helen van Meter of Chenango Forks.  She had lived in Ithaca for only a few weeks, and had been employed by the Ithaca Bakery since mid-December. 

Police are investigating.

I sat in my room, crying and reading the article over and over.  Sometimes you still cry even when you know how the story’s going to end.  But perhaps, if the story is read backwards, it will have a happier ending.

 

Or beginning.  Or whatever.

At least that’s what I am hoping for.

*********************************************

I've been interested for a long while in creativity -- where it comes from, why different people choose different sorts of creative outlets, and where we find our inspiration.  Like a lot of people who are creative, I find my creative output -- and my confidence -- ebbs and flows.  I'll have periods where I'm writing every day and the ideas are coming hard and fast, and times when it seems like even opening up my work-in-progress is a depressing prospect.

Naturally, most of us would love to enhance the former and minimize the latter.  This is the topic of the wonderful book Think Like an Artist, by British author (and former director of the Tate Gallery) Will Gompertz.  He draws his examples mostly from the visual arts -- his main area of expertise -- but overtly states that the same principles of creativity apply equally well to musicians, writers, dancers, and all of the other kinds of creative humans out there. 

And he also makes a powerful point that all of us are creative humans, provided we can get out of our own way.  People who (for example) would love to be able to draw but say they can't do it, Gompertz claims, need not to change their goals but to change their approach.

It's an inspiring book, and one which I will certainly return to the next time I'm in one of those creative dry spells.  And I highly recommend it to all of you who aspire to express yourself creatively -- even if you feel like you don't know how.

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

Watching the clock

 If I had to pick the scientific law that is the most misunderstood by the general public, it would have to be the Second Law of Thermodynamics.

The First Law of Thermodynamics says that the total quantity of energy and mass in a closed system never changes; it's sometimes stated as, "Mass and energy cannot be destroyed, only transformed."  The Second Law states that in a closed system, the total disorder (entropy) always increases.  As my long-ago thermodynamics professor put it, "The First Law says you can't win; the Second Law says you can't break even."

Hell of a way to run a casino, that.

So far, there doesn't seem to be anything particularly non-intuitive about this.  Even from our day-to-day experience, we can surmise that the amount of stuff seems to remain pretty constant, and that if you leave something without maintenance, it tends to break down sooner or later.  But the interesting (and less obvious) side starts to appear when you ask the question, "If the Second Law says that systems tend toward disorder, how can a system become more orderly?  I can fling a deck of cards and make them more disordered, but if I want I can pick them up and re-order them.  Doesn't that break the Second Law?"

It doesn't, of course, but the reason why is quite subtle, and has some pretty devastating implications.  The solution to the question comes from asking how you accomplish re-ordering a deck of cards.  Well, you use your sensory organs and brain to figure out the correct order, and the muscles in your arms and hands (and legs, depending upon how far you flung them in the first place) to put them back in the correct order.  How did you do all that?  By using energy from your food to power the organs in your body.  And to get the energy out of those food molecules -- especially glucose, our primary fuel -- you broke them to bits and jettisoned the pieces after you were done with them.  (When you break down glucose to extract the energy, a process called cellular respiration, the bits left are carbon dioxide and water.  So the carbon dioxide you exhale is actually broken-down sugar.)

Here's the kicker.  If you were to measure the entropy decrease in the deck of cards, it would be less -- way less -- than the entropy increase in the molecules you chopped up to get the energy to put the cards back in order.  Every time you increase the orderliness of a system, it always (1) requires an input of energy, and (2) increases the disorderliness somewhere else.  We are, in fact, little chaos machines, leaving behind a trail of entropy everywhere we go, and the more we try to fix things, the worse the situation gets.

I've heard people arguing that the Second Law disproves evolution because the evolutionary model claims we're in a system that has become more complex over time, which according to the Second Law is impossible.  It's not; and in fact, that statement betrays a fundamental lack of understanding of what the Second Law means.  The only reason why any increase in order occurs -- be it evolution, or embryonic development, or stacking a deck of cards -- is because there's a constant input of energy, and the decrease in entropy is offset by a bigger increase somewhere else.  The Earth's ecosystems have become more complex in the 4.5 billion year history of life because there's been a continuous influx of energy from the Sun.  If that influx were to stop, things would break down.

Fast.

The reason all this comes up is because of a paper this week in Physical Review X that gives another example of trying to make things better, and making them worse in the process.  This one has to do with the accuracy of clocks -- a huge deal to scientists who are studying the rate of reactions, where the time needs to be measured to phenomenal precision, on the scale of nanoseconds or better.  The problem is, we learn from "Measuring the Thermodynamic Cost of Timekeeping," the more accurate the clock is, the higher the entropy produced by its workings.  So, in effect, you can only measure time in a system to the extent you're willing to screw the system up.

[Image licensed under the Creative Commons Robbert van der Steeg, Eternal clock, CC BY-SA 2.0]

The authors write:

All clocks, in some form or another, use the evolution of nature towards higher entropy states to quantify the passage of time.  Due to the statistical nature of the second law and corresponding entropy flows, fluctuations fundamentally limit the performance of any clock.  This suggests a deep relation between the increase in entropy and the quality of clock ticks...  We show theoretically that the maximum possible accuracy for this classical clock is proportional to the entropy created per tick, similar to the known limit for a weakly coupled quantum clock but with a different proportionality constant.  We measure both the accuracy and the entropy.  Once non-thermal noise is accounted for, we find that there is a linear relation between accuracy and entropy and that the clock operates within an order of magnitude of the theoretical bound.

Study co-author Natalia Ares, of the University of Oxford, summarized their findings succinctly in an article in Science News; "If you want a better clock," she said, "you have to pay for it."

So a little like the Heisenberg Uncertainty Principle, the more you try to push things in a positive direction, the more the universe pushes back in the negative direction.  

Apparently, even if all you want to know is what time it is, you still can't break even.

So that's our somewhat depressing science for the day.  Entropy always wins, no matter what you do.  Maybe I can use this as an excuse for not doing housework.  Hey, if I make things more orderly here, all it does is mess things up elsewhere, so what's the point?

Nah, never mind.  My wife'll never buy it.

****************************************

When people think of mass extinctions, the one that usually comes to mind first is the Cretaceous-Tertiary Extinction of 66 million years ago, the one that wiped out all the non-avian dinosaurs and a good many species of other types.  It certainly was massive -- current estimates are that it killed between fifty and sixty percent of the species alive at the time -- but it was far from the biggest.

The largest mass extinction ever took place 251 million years ago, and it destroyed over ninety percent of life on Earth, taking out whole taxa and changing the direction of evolution permanently.  But what could cause a disaster on this scale?

In When Life Nearly Died: The Greatest Mass Extinction of All Time, University of Bristol paleontologist Michael Benton describes an event so catastrophic that it beggars the imagination.  Following researchers to outcrops of rock from the time of the extinction, he looks at what was lost -- trilobites, horn corals, sea scorpions, and blastoids (a starfish relative) vanished completely, but no group was without losses.  Even terrestrial vertebrates, who made it through the bottleneck and proceeded to kind of take over, had losses on the order of seventy percent.

He goes through the possible causes for the extinction, along with the evidence for each, along the way painting a terrifying picture of a world that very nearly became uninhabited.  It's a grim but fascinating story, and Benton's expertise and clarity of writing makes it a brilliant read.

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

Views of the block universe

In the beginning of my as-yet unpublished novel In the Midst of Lions, the character of Mary Hansard realizes one day that she can no longer tell apart the past and the future.

She has memories of both -- if you can call a mental picture of something from the future a memory -- and they both carry equal weight in her brain.  She can determine which is which only in the rare cases where she can verify if an event has occurred yet, such as her "memory" that a building in her neighborhood had burned down, when the (intact) building itself is right in front of her.  But in other cases, such as a conversation between her and a friend, she has no way to know whether it has already happened, or will happen in the future.

For Mary, there aren't three classes of events -- past, present, and future.  There are only two: present and not-present.  A good chunk of the first part of the book is an exploration of how that would affect someone psychologically.  (A summary: "not well.")

The funny thing is that there's nothing in this situation that specifically breaks the laws of physics.  (It's not accidental that I made the character of Mary a high school physics teacher.)  In 2019 I wrote about the peculiar and unresolved problem of "the arrow of time" -- that virtually all physical processes are time-reversible, meaning that they work equally well backwards and forwards.  A simple example is if you watched a video of a pool ball bouncing off the bumper of a billiards table, then ran it backward, there would be no obvious way to tell which was which.  (If you had a longer video, you might be able to tell, because friction with the table would bleed away energy from the ball, causing it to slow down -- so the forward version is the one that shows the ball slowing down, and the backward version is the one in which it speeds up.  This is the approach of the arrow of time problem from the angle of the Second Law of Thermodynamics; if you want to know more, you can check out my post linked above.)

So in terms of physics, it's mystifying why we perceive an arrow of time, when it seems like there's no reason we shouldn't have equal access to both past and future.  "Time is an illusion," Albert Einstein said, "but it is a remarkably persistent one."

Things get even weirder when you start looking into physicist Hermann Minkowski's idea of a block universe, where the three dimensions of space and one of time are mapped onto a three-dimensional solid.  Picture it as a loaf of bread that you can slice at any angle.  The angle of the slice is determined by the relative speed of your reference frame in comparison to the reference frame of what you're looking at, but what it leads us to is that the present loses its simultaneity -- two events that are simultaneous in one reference frame might occur sequentially in another.  Pushed to its ultimate conclusion -- and it must be interjected at this point that once again, there is nothing about Minkowski's ideas that breaks any known law of physics -- this means that an event that is in the past for me might be in the future for you, and therefore all of temporal sequencing is relative.  Minkowski showed that you can model the universe as a block within which exists not only everything in space, but everything in time.  The fact that we haven't gotten to events in the future is no more remarkable than the fact that we haven't gotten to some locations in space yet.  They're still out there, they still exist, even if we haven't seen them.

Kind of casts a harsh light on the concept of free will, doesn't it?

In any case, the topic comes up not because of physics, but because of an article by science writer Eric Wargo over at the site Inner Traditions called "The Amazing Reality of Dream Precognition."  It's an unfortunate choice of titles, because the article is well written and way less woo-woo than it sounds.  Wargo is seriously trying to figure out if people have access to the future, specifically through dreams, and has a project going to do some citizen science and have a large number of people record their dreams, then sift through them to see if there are examples of actual precognition.

It's an interesting idea, although there are some difficulties.  One is that Wargo claims that a lot of dream precognition is symbolic in nature; for example, you might dream of seeing a photograph of a friend shattered into pieces, and soon after she is injured in a terrible automobile accident.  But this requires that we rely on our own interpretation of the symbols after the fact.  And if there's one thing I've learned from ten years of writing here at Skeptophilia, it's that humans are really good at remodeling what actually happened to fit with what they think happened.

That said, Wargo is going about things the right way.  One of the things that has plagued serious research into precognition is that you only know a dream (or thought) is precognitive after the event has occurred, at which point there's always the possibility that your memory of the allegedly precognitive event has been contaminated by your knowledge of what really happened.  Also, there's the unfortunate fact that there are lots of cases of outright falsification.  If the records are made beforehand, this reduces the likelihood of this sort of thing, although it still requires that there be some kind of rigorous standard for keeping track of when the records were written down relative to the event they allegedly predicted.

So the idea is interesting, to say the least, and I need to keep in mind that my inclination to say "this is impossible" is itself a bias.  Even the lack of a mechanism for precognition -- something about which I've written before -- sort of evaporates if Minkowski was right about the block universe.  It still might not explain how you and I, both on the same planet moving at the same speed in the same reference frame, have access to different slices of the spacetime loaf, but at least it takes away one of the most consistent objections, which is that the future is fluid and therefore precognition would constitute looking at something that has no physical reality.

Reminds me of the "fixed points in time" in Doctor Who.  Maybe the truth is that everything is a fixed point in time, not just big events like the eruption of Pompeii.

So I'll be interested to see what Wargo comes up with.  Me, I'm keeping an open mind about the whole thing, as counterintuitive as it may seem to me.  If he can come up with actual evidence of precognition, dream or otherwise, it'll force me to re-evaluate a good chunk of how I think the world works.  And my character of Mary Hansard in In the Midst of Lions may turn out to be a rather alarming case of Plato's belief that "art mimics life."

********************************

If, like me, you love birds, I have a book for you.

It's about a bird I'd never heard of, which makes it even cooler.  Turns out that Charles Darwin, on his epic voyage around the world on the HMS Beagle, came across a species of predatory bird -- the Striated Caracara -- in the remote Falkland Islands, off the coast of Argentina.  They had some fascinating qualities; Darwin said they were "tame and inquisitive... quarrelsome and passionate," and so curious about the odd interlopers who'd showed up in their cold, windswept habitat that they kept stealing things from the ship and generally making fascinating nuisances of themselves.

In A Most Remarkable Creature: The Hidden Life and Epic Journey of the World's Smartest Birds of Prey, by Jonathan Meiberg, we find out not only about Darwin's observations of them, but observations by British naturalist William Henry Hudson, who brought some caracaras back with him to England.  His inquiries into the birds' behavior showed that they were capable of stupendous feats of problem solving, putting them up there with crows and parrots in contention for the title of World's Most Intelligent Bird.

This book is thoroughly entertaining, and in its pages we're brought through remote areas in South America that most of us will never get to visit.  Along the way we learn about some fascinating creatures that will make you reconsider ever using the epithet of "birdbrain" again.

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

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.

********************************

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!]