Time, Space, and Quantum Mechanics

Ken Taylor
Welcome to Philosophy Talk, the program that questions everything…

John Perry
…except your intelligence. I’m John Perry.

Ken Taylor
And I’m Ken Taylor, and we’re coming to you from the studios of KALW San Francisco.

John Perry
We’re continuing conversations that began at philosophers corner on the Stanford campus.

Ken Taylor
Today: the metaphysical mysteries of time, space and quantum mechanics.

John Perry
Quantum mechanics was developed in the last century to deal with the tiniest parts of nature. It seemed that classical physics which was able to describe everything from the movement of stars to the movements of grains of sand wasn’t enough, a whole new theory was needed.

Ken Taylor
And it’s a whole new theory. That’s a special theory. I mean, we owe a lot to quantum mechanics, modern bombs and modern computers, for example, it’s been called the most empirically powerful and accurate theory ever developed.

John Perry
But quantum theory has been a pain or at any rate, a challenge for philosophers since it began. In the first place, the quanta turned out to be neither particles which we can imagine or waves, which we can imagine. But something that shares the properties are both in a way that’s impossible to picture.

Ken Taylor
And what’s even more worrisome is the strange role of the observer. In quantum mechanics. The idea seems to be that quantum systems move along from quantum state that quantum state in a perfectly predictable and unproblematic way, until you put the observer in the picture.

John Perry
But these quantum states seem to be just probabilities about what’s happening. As soon as there is an observer things have to resolve themselves one way or another. And this seems not to be determined by the quantum state.

Ken Taylor
So use a Schrodinger his famous cat example, you put a cat in a box with a bottle of gas rigged up so that if a particle ends up in one place, the gas will be released and the cat, the poor cat will die. But if it doesn’t end up in that place, but someplace else the cat’s gonna be okay.

John Perry
Quantum Theory tells us exactly what the probabilities are. But now what actually happens, when someone opens the box and looks in the Cat’s got to be either alive or dead. Somehow the observer forces the world to make up its mind in a way that the laws of quantum physics don’t?

Ken Taylor
Well, you know, some physicists and some philosophers say that what happens is that the world splits with the cat living in some worlds and not in others, matching the probability. So if there’s a 5050 chance and half the worlds that lives and afterwards it dies, can that’s really weird. Absolutely weird, John. But you know what, that’s an old problem. That’s an old mystery. Over the last 25 years or so attention is focused on yet another quantum mystery entanglement. And what some physicists say about entanglement, you know, it makes my head spin. It makes us philosophers feel like we’ve been kicked back inside Plato’s cave, that the familiar world, the one spread out in space, and changing over time, is just an illusion.

John Perry
Well, here’s how I understand it, which is, of course, is barely, but suppose you and I can our particles were generated by some subatomic process, we fly off in opposite directions that close to the speed of light. After a while we each raise exactly one of our hands, we do so simultaneously relative to an observer at the place where we began.

Ken Taylor
So it seems like if you just think about it, there should be like a 50-50 chance that we’ll raise opposite hands or the same hands. But look, it turns out that we raised the opposite hand, not 50% of the time, but three quarters of the time. Somehow, despite the fact that we’re traveling at close to the speed of light. What one of us does depends on what the other does. Our states are, as they say, entangled, even after a few minutes, where 1000s or even millions of miles apart. But here’s the mystery: how?

John Perry
It can’t be that we’re influencing other, but say sending signals, because no signal could go faster than the speed of light. So it couldn’t get from me to you or you to me in time to help us coordinate our actions. It seems like this better than chance correlation is some kind of miracle.

Ken Taylor
But quantum physicists don’t believe in miracles and they know that this is how the universe actually work. And even they are finding it hard to explain. So what do we poor philosophers to do?

John Perry
Some of their attempts at explaining it are really upsetting. Our guest, Jenann Ismael, uses the analogy of living inside a kaleidoscope to explain a leading idea.

Ken Taylor
So either we’re living in Plato’s cave or Ismail’s kaleidoscope, seeing shadows are mirror images with no way of knowing what the true relations between the causes of those images are. That’s depressing.

John Perry
Jenann Ismael, who will be joining us in a minute, is a philosopher of physics from the University of Arizona. She’s the author of “Essays on Symmetry” and “The situated Self.” As far as we can tell, she’s coming to us from a studio in Tucson, but maybe along some other dimensions. She’s sitting with us here in San Francisco, or maybe we’re in Arizona too.

Ken Taylor
Well, no matter what dimension you find yourself in. We want you to be part of this conversation.

John Perry
But first we’re going to hear from our Roving Philosophical Reporter, Caitlin Esch. She explores the uses and misuses of quantum physics in film and television. She files this report.

Caitlin Esch
There’s a scene in the television series “Fringe.” It’s the last episode of the first season, where a portal opens to an alternate universe and one of the characters slips through.

Fringe
You’re saying that William Bell disappeared into a different universe, like Dorothy going to Oz. Walter calls it an alternate reality. Do you understand? Not remotely. You’re saying there William Bell, he’s not on this planet? No, he is just another version of this planet.

Caitlin Esch
Sounds like the work of science fiction, right. But according to the many worlds interpretation of quantum physics, there are actually an infinite number of universes all around us with infinite possibilities.

Chad Orzel
Odd as it may seem, it’s a solution to a problem.

Caitlin Esch
Char Orzell is a professor at Union College in Schenectady, New York and the author of “How to Teach Physics to Your Dog.” He says the rules of quantum physics allow us to predict what will happen in the future.

Chad Orzel
What those rules say is that objects can be in more than one place at the same time, for example. And the reason we don’t see an electron being in more than one place at the same time is that it continues to be in multiple places. But the universe sort of splits we effectively have a universe in which the electron is here and we see it here, and a universe in which the electron is there and we see it there.

Caitlin Esch
This is great material for screenwriters.

Star Trek
Space—the final frontier.

Caitlin Esch
In this episode from the original Star Trek series, an Ion Storm causes Captain Kirk and his crew to switch places with their doubles in a parallel universe. Only their doubles are evil. Captain Kirk realizes this when a bearded alternate version of Mr. Spock tortures a subordinate,

Star Trek
Mr. Kyle, you were instructed to compensate during the ion store, but I tried to the equipment cannot be tolerated, but there’s just no, it’s just your agonizer please, no, Mr. Spock.

Chad Orzel
The interesting thing about that is if you take this sort of theory seriously, there has to be that kind of universe out there. There has to be a universe out there where everything is the opposite of what we have here.

Caitlin Esch
And that raises the question, how close are we to our alternate selves,

Chad Orzel
The Star Trek treatment of it is ultimately a little bit silly. But as an idea, that’s something interesting that it’s out there that if you’re kind to animals, you nevertheless know that there should be some universe out there in which you regularly kick puppies.

Caitlin Esch
While shows like fringe and Star Trek raise interesting ideas, the scientific implausibility of colliding universes bothers Orzel.

Chad Orzel
That’s a failing and shows like Fringe, is that the world in the other universe is really radically different. And yet, you have the alternate versions of the characters from our universe, have the same jobs and that their parents are the same people. And they live in the same unrealistic New York City to large apartments.

Caitlin Esch
One small change in the past would lead to bigger and bigger consequences. The best example of this idea according towards owl doesn’t come from science fiction. It comes from the 1946 Christmas classic, “It’s a Wonderful Life.”

It’s a Wonderful Life
I suppose it’d be better if I’d never been born at all. You’ve got your wish. You’ve never been born, you don’t exist.

Chad Orzel
They work out in detail the effects of changing one thing in the past, and it’s not treated as a parallel universe that exists. It’s just something that’s shown to one of the characters.

It’s a Wonderful Life
Your brother Harry Bailey, broke through the ice and was drowned at the age of nine. That’s a lie, Harry Bailey went to war, he got the Congressional Medal of Honor. He saved the lives of every man on that transport. Every man on that transport died, Harry wasn’t there to save them because you weren’t there to save Harry.

Caitlin Esch
In the film, you see that one man’s existence impacts everything from the name of the town to the death of a brother. And even though it’s total fantasy, it might just be realistic.

Speaker 1
You see, George, you really had a wonderful life.

Caitlin Esch
For Philosophy Talk, I’m Caitlin Esch.

John Perry
I’m John Perry with me is Ken Taylor.

Ken Taylor
And our guest is to Jenann Ismael. She’s a professor of philosophy at the University of Arizona. She’s author of “Essays on Symmetry” and “The Situated Self.” Those are two books not one. Jenann, welcome back to Philosophy Talk.

Jenann Ismael
Thanks so much for having me.

John Perry
So Jenann, firs, a question about you. What drew you to thinking about quantum physics? Did you just kind of get off on the mysteries, or do they offend you and you got in there so you could get rid of them?

Jenann Ismael
Gosh, that’s a hard question. I think maybe it’s a bit of both. I’d say that. They sort of drive me crazy, but I can’t stop thinking about them. And you keep thinking that you’re going to get to the bottom of it. But it’s punishing because you don’t you just keep digging and it gets more and more mysterious. So maybe those who are close to me would say It’s a bit of perverse enjoyment.

John Perry
Okay. Now, Ken and I, in our intro gave a kind of, I suppose, pretty amateurish introduction to this entanglement problem. So why don’t you start by cleaning up our exposition a little and then explain this business about a kaleidoscope and how it is a metaphor for a theory that people have about all of this.

Jenann Ismael
I actually think you did quite a good job in introducing the idea of entanglement, this idea that there are apparently coordinated actions that take place in different parts of space. And that can’t be explained by signals or causal influences traveling between them, or buy a kind of pre arranged recipe that you’d both be following that would guarantee that sort of coordination, that sort of explanation just doesn’t seem to work. But there’s another feature of quantum mechanics that you didn’t talk about, that’s at least as important. And in fact, the two are tied together like two sides of the same coin. And some people think that, that entanglement is the central heart of the mysteries of quantum mechanics. Other people think that this other feature, which I’m going to call complementarity is the central heart. But really, the truth is that there are two sides of the same coin. And together, they capture the central mysteries. So if you understand these two features of quantum mechanics, then you’ve really unlocked the key to the quantum universe. Okay,

John Perry
So tell us about the complement complementarity.

Jenann Ismael
Well, actually, you, you introduce the image of a kaleidoscope, but there’s another image, it’s a little bit more complicated, but it does a better job of, I think, capturing these two features of quantum mechanics. And it’s easy to visualize. And it comes actually, the image comes from Boehm, who’s sort of one of my favorite philosophers and physicists, and he says, look, think about a fish tank. Imagine a fish tank, an ordinary three dimensional fish tank with a bunch of fish in it, maybe you’ve got some plants in there. And what you’ve got is a camera pointed at the front of the fish tank and projecting an image on a screen in another room, a flat two dimensional screen, another room on the other side of the fish tank, so it kind of perpendicular to it looking from the side or not, from the front on, you’ve got another camera cameras looking at same fish tank, and it’s projecting its image on a screen right next to the screen that the first camera is projecting onto, they’ve got a flat two dimensional screen and imagine that there’s no kind of visible difference between the two sides. So they’re just kind of integrated. So it looks like you’ve got a single screen. And they’re both projecting side by side images of the same tank, one from the front and one from the side. Okay, so now think about what you would see, right, you’d see images on that screen. But for every fish and every movement of the fish, you’d see it projected in two places on the screen. And you can see, I mean, knowing what you do about what fish tanks look like and what, you know, flat images projecting from different sides of the fish tank look like you can start to picture, you know what you’d see on the screen. And you’d see, in particular, you’d see these weird sorts of coordinations, were you know, every time you’d see an action on one side of the screen, you’d see a kind of parallel action on the other side of the screen. And you’d know that, you know, these sort of coordinated actions weren’t explained by any causal influences passing through the space of the screen, or that there was some sort of communication between the two images, you’d know that what you were seeing was actually a lower dimensional projection of what’s a higher dimensional reality, so that you were seeing multiple images of the same fish and the same actions on different parts of the screen, and they wouldn’t be sort of directly copies of one another, they’d be a little bit more complicated. One would be a side on view, when you had the, you know, a front on view of the other side, when you saw a fish turn through one angle on the on one side of the screen, you’d see a different image, you know, turning through a different angle on the other side of the screen. So now focus on the changing images of some particular fish as the fish turns through an angle. So you’d see on the one hand, the aspect that was presented on one side of the screen, would disappear and be replaced by another. So let’s say that the fish the view of the fish from one angle, kind of occludes, the view of the fish from another so that they can appear simultaneously on the screen individually, but never together a full frontal view, completely occludes a view from the back, a left side view, includes a view from the right, and so on. So you get these weird relations of mutual occlusion so that you can’t simultaneously see the different views. And it would be natural to think that the that views that excluded one another of the views that excluded one another as complementary.

John Perry
So Jenann, we’re not going to have time to go much further than this. It’s a great analogy season, we have one slight flaw that we can discuss in the next segment. That is we’re in the fish tag. We’re not in the next room or part of the universe.

Ken Taylor
You’re listening to Philosophy Talk. Today we’re talking about the mysteries of time space in quantum mechanics with Jeanette Ismael from the University of Arizona,

John Perry
How do you feel about living in oh, I don’t know in a kaleidoscope or now in a in a room with two images of the universe that you can’t coordinate just quantum physics vindicate the mystics whose long claim the world is more mysterious than it seems? Or does it just show that some problems are too hard even for scientists to figure out

Ken Taylor
Quantum physics, life inside the cave, and the mysteries of the universe—when Philosophy Talk continues?

The Beatles
Nothing’s gonna change my world

John Perry
Time and space spread out across the universe—that might change your world. We’re talking about quantum mechanics. I’m John Perry.

Ken Taylor
And I’m Ken Taylor. And this is Philosophy Talk. Does the world we live in feel like the world described by quantum theory? Does quantum theory fundamentally change what we know about the world and how we should think about the world? Any quantum physicists out there with a better way of solving the mystery of entanglement? Join the conversation, if you’re out there,

John Perry
Our guest is Jeanette Ismael from the University of Arizona.

Ken Taylor
So Jenann, you have this complicated metaphor with the fish tank, which I think I got most stuff, but there’s one thing that bothers me a little bit. And maybe you can help clear this up. You talked about two cameras looking at in the fish tank. And you know, these included perspectives, but the fish one fish looked at from food perspective is still one fish, and the correlations are explainable. Because, you know, there’s one fish looked at in two different ways. But John and I, we, in our little setup, were two different particles, correlated nonetheless, but no signal transiting, transiting between us no causal signal, possibly transit, yet these two distinct particles remain correlated. Am I missing something? Is your analogy?

Jenann Ismael
Well, I think the thing that the thing to focus on is that what what you’re supposed to think of as the space that we see, the ordinary three dimensional space that evolves in time, that we think of as a space in which we live is supposed to be the analogy, in the fish tank example that I gave of this sort of two dimensional screen, that the people in another room would see if they were just looking at the images projected by the fish. So really, we know because we set the analogy up, that there’s this, you know, higher dimensional reality, in this case, a three dimensional reality with three dimensional fish. And there’s only one fish, but the people in the other room wouldn’t know that they would be looking at a lower dimensional reality, a two dimensional screen, and they would see multiple images of the same fish projected at different places on the screen. And they would be scratching their head saying, what explains the coordination between the different sides of the screen?

Ken Taylor
Are you telling me that these correlated what looked to us like correlated, mysteriously correlated distinct particles between which no signal can pass no causal influence contests? Really, we shouldn’t think of them as one party as two particles. But as one, is that what you’re doing?

Jenann Ismael
That’s exactly right. So the idea is that these multiple images is really a bit of trickery, like the multiple coordinated images, you save yourself in a hall of mirrors, you know, when you look around, you see multiple images of yourself. And just like, as you said, the six or eight symmetric images of a little red piece of glass that you see when you look through the lens of a kaleidoscope. So what we see, as you know, two particles behaving in a strangely coordinated way, it’s really a single particle living in a higher dimensional space, that’s just doing its thing.

John Perry
But Japan, these particles are going away from each other, close to the speed of light, after, you know, a little while one of them might be on the far side of some other galaxy. I mean, how could they possibly be one? Well, you say in a different dimension. But that’s still I mean, the unity of the object seems to have disappeared. Can we really? Can you really imagine that that’s true.

Jenann Ismael
You’re still thinking of the ordinary three space that we live in.

Ken Taylor
He’s in Plato’s cave, Jenann.

Jenann Ismael
That’s exactly right. Imagine, imagine someone who’s looking through a kaleidoscope and who doesn’t sort of, you know, have this ordinary three dimensional picture of themselves, all they see all sort of their complete experience is comprised of looking through the lens of a kaleidoscope and they see, you know, every time there’s a red image at one place in the kind of visual space of the kaleidoscope, there’s a corresponding image at another place in a corresponding image another and they turn the bottom of the kaleidoscope, and they see changes in the image but always that preserves the symmetries of the space are looking through and they’re wondering, how does the red image on the top right corner? How does it know so Janae what’s going on in the—

John Perry
So Jenann, throughout the history of humankind, there’s been people who said the universe is very mysterious. And maybe they’ve used that to account for things like pre cognition, and extrasensory perception, and reincarnation. Is quantum physics, just opening the door to all these things and saying, Oh, yes, no wonder people can know about things that are happening on the other side of town. They’re probably really there in another dimension. This is pretty weird.

Jenann Ismael
Well, what quantum mechanics does is it makes us reexamine our ordinary ideas about what the way and this is putting it in a way, I think that makes some contact with the sorts of mysteries that you talked about, with the way that information is spread around in space. In classical mechanics, and our ordinary kind of common sense ideas of the way information is spread around in space, we can only know stuff about the past. And the way that we know stuff about the past is that signals travel from stuff, you know, in, in the past, to the present in quantum mechanics, those sorts of nice tidy relations, about you know, what we can know about just by ordinary sort of physical signals, those aren’t preserved. So it opens the door to new new questions about just you know, what we can know about and how we can know about the things that we know about.

Ken Taylor
You’re listening to Philosophy Talk, we’re talking the metaphysical mysteries of time, space, and quantum mechanics with Jeanette Izmail. We’d love to have you join this conversation. And Joe and Oakland’s on the line. Welcome to Philosophy Talk, Joe.

Joe
Yeah, hi, can you hear me?

Ken Taylor
Yeah, we can hear you. What’s your question?

Joe
I was gonna ask about the little something about the observer, sort of a slightly two part question. First of all, does the observer have to be a human being? Can it be another animal? And if the observer has to be alive in any way, life on earth has only been around say, let’s say 4 billion years, which leaves 10 billion years in the past? When, if there was no observer, basically, nothing happened? Can you help me out with that?

Ken Taylor
I think you’re a little confused. Here to straighten you out here.

Jenann Ismael
Actually a really good question. So there are some interpretations of quantum mechanics. And the one that I was proposing is one of these, that doesn’t give the the observer any role at all. But there are other interpretations of quantum mechanics in which the observer or the at least the act of observation, or as it sometimes put measurement, does play a large role. And it is an open question and a very hard question for those interpretations. Exactly. When this sort of action of the observer makes a difference to the state of the universe.

Ken Taylor
Does it have to be a conscious thinking creature? Or is it can’t the observer just be any sort of macroscopic thing that interacts with this causally?

John Perry
I mean, what like a Geiger counter? Yeah, right?

Ken Taylor
Isn’t a Geiger counter an observer?

Jenann Ismael
It’s It depends. Some people think that it’s not actually until the result of the Geiger counter measurement is registered in the consciousness of a human being or some other kind of conscious being, that there is actually a change in the state of the universe. Up until that moment, the Geiger counter just gets kind of involved in the entangled state of the system that’s being measured.

John Perry
So this is what they call a collapse of the wavefunction. Or am I way off confusing to things?

Jenann Ismael
No, that’s exactly right. That’s exactly right. So at some point in the evolution of the system, before you get to say whether there’s actually, you know, a dead cat or an alive cat, or at the moment at which you actually get to say there’s a dead cat or an alive cat, the states that work kind of superimposed on one another, so to speak, in the quantum state of the cat get disentangled or Decaux hair, as it sometimes said. And that’s the moment at which there’s definitively alive cat or a dead cat. And the question is, when is that moment? And what is it that that forces the decoherence?

John Perry
Okay, now, some quantum physicists and philosophers of quantum physics have tried to explain to me the plausibility idea that every time we might have a collapsing wavefunction, we actually are splitting worlds. Now, what’s the connection between that idea if I’ve got it straight, and your explanation of entanglement as your explanation of entanglement, do away with the need to have splitting universes?

Jenann Ismael
It’s a good question. I mean, I think the idea of many universes that comes out of this sort of that’s associated with the every new interpretation of quantum mechanics is that the universe as you said, splits every time a measurement is carried out into branches that appear to their inhabitants as self contained universes. And in each one of these universes, one or another, the possible results of the measurement is realized. So that there’s some weird way in which the states that were superimposed on one another before the measurement had the effect of separating them from another so they could evolve separately. But there’s it’s not there’s not actually any simple connection between that proposal and my proposal, my proposal is one universe, but it’s a higher dimensional universe. And there’s no sense in which the things that you see in ordinary 3d space are splitting, or there’s some sort of dynamical interaction that that sort of restricts the inhabitants to one part of the universe. One of the interesting things about, you know, some of these proposals that have been coming up in different parts of physics that seem to, in one sense, or another suggest, you know, hidden realities, either, you know, much larger universe, which were confined to one part, or in the case that I’m describing a kind of higher dimensional universe that we see only kind of a lower dimensional projection of is that they’re coming up in all sorts of ways to deal with different problems. And it’s not actually clear at all, what the connections between them are.

Ken Taylor
Keith in San Francisco and online, welcome to philosophy Talk, Keith.

Keith
Thank you. I’m also a UV alumnus. My question concerns, how does probability figure in the concept of the many worlds theory, what I’ve read over a number of years is just as has been described, that when anything has the possibility of going one way or the other, it actually goes into both wavefunction collapse and to have multiple units versus however, the probability of those events are not always equal. So when you have say something that’s 90%, likely, does that mean, nine universes that are created one way and one universe is created the other way? Or? Basically, that’s what I’m trying to find a good question.

Ken Taylor
Well, what do you think? What’s the answer?

Jenann Ismael
Good question. Very hard question for people who are advocates of the Eveready. In approach, there’s a number of answers out there right now. But I think probably the most vividly imaginable and plausible one is something like the idea that you said, namely, that there’s, it’s a little bit more complicated, because we’re dealing with infinities rather than finite sums. But it is basically something like when the universe splits, it splits in a way that the proportions of the numbers of universes, that that number of different sort of de cohered branches of the universe that there are after the measurement corresponds, in some kind of quantitative way to the probability that a given inhabitant after the fact it’s in a universe that, you know, has whatever result that the probability attaches to.

John Perry
So Japan, you’ve talked a little bit about these different strange theories coming out of quantum mechanics, which are, in a sense, rivals limit, let me just ask about another thing that’s coming out of physics all the way gets more out of cosmology. And that’s the idea that there must be many universes, because otherwise, it would be hard to understand why ours is set with just the parameters for the basic laws of nature that it is, some people use this as an argument for God. But as I understand it, the the idea in cosmology as well, if you think of ours is just a one of a number of universes in the multiverse, each of which had to have its parameter set somewhere, then it’s not amazing that one of them turned out to have the parameters we do, is that a completely separate weird idea from physics.

Jenann Ismael
It’s not a separate, completely weird idea, that proposal that I was suggesting, doesn’t have much to say about it. But the Everett interpretation does, and the other interpretation purports to solve that problem by saying all possibilities are realized. But the reason that we find ourselves in a part of the universe in which the constants have exactly the value that they do in our universe, even though it’s not like that everywhere, and in fact, it’s only like that in a very small part of this larger universe in which all possibilities are realized as well. Of course, we find ourselves in a corner of the universe in which life was possible, and not just life, but life of the kind that gives rise to conscious cognitive beings of the sort we are because there just aren’t beings in other parts of the universe that have those qualities.

John Perry
So does it bother you that the interpretation you favor doesn’t solve that problem, but the Everett interpretation does?

Jenann Ismael
I’m not convinced that it’s a very good solution. And I think that no, it doesn’t. I mean, it’s a question about what you think needs to be explained.

Ken Taylor
Jenann, I have a slightly different kind of question. This all sounds like metaphysics, not I mean, I don’t physicists proposal this, but how could you possibly decide between these competing interpretations of quantum is this is it has physics devolved into like pure philosophy, or am I missing some? I mean, I know relativity theory used to cause people loop but you can figure out what the curvature of your space time because you can calculate what sort of geometrical formulas apply to figures in your space time you can, you know, you walk around if you’re living on a globe, then a triangle is going to have a different This angles aren’t gonna summon the same way. But how do you how do you decide about this multi universe versus multi dimensional? He tells seems mind boggling.

Jenann Ismael
First, it’s very funny that you suggest that physics has devolved into philosophy I when might just as well say it’s evolved, okay, it’s gotten to the depth, it’s gotten to the point in the discussion, where it’s now doing some real soul searching about the most fundamental sort of assumptions that we make about the structure of space, time and matter. I think of it as one of the most lovely features of modern physics is it’s raising those questions and raising them in new and unimagined ways.

Ken Taylor
I grant that but doesn’t have any way of solving them. Science is supposed to have means of solving problems that philosophers can’t emulate. Does it have means? Or does it only have, you know, overall coherence and stuff like that which philosophers trade in to, as its tool?

Jenann Ismael
I think ultimately the same it does have experimental results, or experimental results and experimental methods at its disposal. But what those experimental results and methods can do is give you a more and more detailed and precise and fine grained understanding of the observable structure of space and time. And then the questions arise, because we know I mean, we can prove formally that there are always going to be no matter how precise you get, no matter how detailed your description of the observable structure of space and time is, no matter how good your measurements get at probing the microscopic structure of matter. Ultimately, what you’re going to have is a detailed description of the observable structure of space and time. And philosophers realized long ago that there’s going to be multiple competing incompatible hypotheses about what the deep structure of the world is compatible with all of that.

Ken Taylor
You’re listening to Philosophy Talk, we’re talking about the metaphysical mysteries of time space in quantum mechanics, with Jenann Ismael from the University of Arizona.

John Perry
We seem to have a choice with quantum mechanics, we can accept that the world is really a strange place that most of which we can’t imagine and ordinary people have no contact with, because science tells us so. Or maybe we’re taking science too seriously. Maybe its job is just to give us some calculating rules that allow us to predict and control nature. And we shouldn’t press it for answers beyond that. We shouldn’t ask it to tell what nature is really like.

Ken Taylor
Science, nature, and your calls—when Philosophy Talk continues.

John Perry
Could there be a fifth dimension beyond that which is known to man? Or a sixth? What about a seventh? Or maybe there’s 11? I’m John Perry. This is philosophy type of program that questions everything…

Ken Taylor
…except your intelligence. I’m Ken Taylor. And our guest is Dan Izmail. from the University of Arizona, we’re talking about the metaphysical mysteries behind space time and quantum mechanics. And we’ve got a lineup of colors who want to join this conversation. Mike in Palo Alto, welcome to Philosophy Talk, Mike.

Mike
Hi, can you hear me?

Ken Taylor
Yeah, we can hear you. What’s your comment or question?

Mike
Oh, my first comment is about metaphysics. And when I hear metaphysician talking to me about physics, I automatically assume they don’t understand it.

Ken Taylor
Well, you would be wrong.

Mike
I would be, okay. Well, most of them make the vast bulk of them make huge mistakes in scale. So they say that something isn’t solid, because there are gaps between the electrons in in the atoms in the table. And that brings me to my second point, which is the scale of things. And I call it the physics of superlatives versus the physics of ordinary objects. It’s for the ordinary world, Newtonian physics explains everything you need to know until you get to things that are extremely large or extremely small. And the line I draw kind of arbitrarily as if something is smaller than a virus or bigger than the solar system, then you need the quantum physics to deal with that.

Jenann Ismael
I think the remark that you made about physics and metaphysics I think a lot of metaphysician say the same about physicists, as soon as they start talking about what nature is really like they sort of make all kinds of mistakes. But I think it is true that there are a small group of both people who are on the border between metaphysics and physics, which are the right people to be addressing questions about what quantum mechanics is really telling. You’re one of them Jeanette,

John Perry
So Jenann, let me let me maybe put this question in a somewhat different way. I mean, the philosopher Berkeley was famous for saying, Well, you know, the world is just ideas and this so called material Real World is just an intellectual construction that people philosophers invented to, to kind of help keep track of the way our sensations work. Well, most people don’t accept that. But some, some philosophers of science say that that’s how kind of how we should think of theories about the very small things about things that really we can’t even see through microscopes, but we only infer as parts of theories about, about patterns we see on instruments, that, that this is all an elaborate calculating device, and it’s great, and it can be confirmed or disconfirmed as far as the calculating device uses. But when you try to understand it as giving us somehow information about the world, you really going beyond what science can do. What do you think of that idea?

Jenann Ismael
Well, quantum mechanics is certainly at least a complicated algorithm for allowing us to make calculations that get the right results, about measurements and about the positions of particles and so on. It’s the formal theory of quantum mechanics as a sort of compact embodiment of regularities that we find in those sorts of measurements and results. But we don’t put those regularities there, we find regularities there, and they must have some explanation. And if we want to understand what nature is like, we have to explain those regularities. So the attempts to interpret quantum mechanics, you know whether or not you think that it’s a proper part of the job of physicists, or proper part of the job of science to be, you know, engaged in explaining what matters really like the intent is to interpreted or really attempt to explain those regularities. And if you want to understand those regularities, you have to understand quantum mechanics, you have to, you have to enter some hypothesis, about the metaphysical substructure that’s actually producing those regularities that quantum mechanics describes.

John Perry
Now, let me ask you a further question. Now going back to kind of this view that you favor. Now, there’s a Copenhagen interpretation of quantum mechanics. And that’s where this talk about the collapse of the wavefunction comes from. Then there’s this other approach. And you you, you mentioned, Boehm was was as one of your heroes. And that’s the hidden variable approach right? Now, I thought that entanglement refuted the hidden variable approach, but you seem to be adopting something like the hidden variable approach. Am I totally confused about that?

Jenann Ismael
No, not at all. First, I should say about both the interpretation that you mentioned, the sort of hidden variables you were you think of. And this is the the interpretation that’s most commonly associated with Beaumes name, where you think of the world as being largely classical. But there are just these hidden variables that are not described in the quantum state that evolve in a roughly classical manner with some funny stuff going on behind the scenes. That’s not the interpretation that I’m suggesting. I think my interpretation also traces back to bone. But he was tremendously fertile imagination. And these are actually two quite different things.

Ken Taylor
Let me tell you different kinds of questions. So all these different kinds of interpretations. But they all have seemed to me to have a consequence. That’s kind of like what John was saying, I just want to hammer that a little bit. space. And time, I’m not sure about time, but space as it ordinarily presents itself to us, like space is the great separator between objects, objects that are different, that exist in different places at different times, and at the same time, are distinct objects unless you just glom on together by some weird, you know, metaphysical lumping, but they’re not really the same. So my computer and your computer, if you’re sitting there, just different computers, because they’re spatially separated, it seems that quantum mechanics is telling us that we don’t really understand the nature of objects and space that we see kind of a shadow of space or something like that. On any interpretation, is that right? Or is that not right?

Jenann Ismael
That’s exactly right. I mean, I think one of the most innovative and interesting things about this proposal is that even though we’ve heard about, you know, proposals coming from string theory about multiple dimensions of space, this proposal is different. Because what String Theory tends to do is it tells you while there’s some sort of hidden dimensions behind the scene, so it preserves the ordinary four dimensional space time or three dimensional space that we actually see. But it’s it leaves that intact, but it tells us there are some hidden dimensions, and that allows them to add degrees of freedom that they can then play with to, you know, try to unify quantum mechanics and gravity or whatever it is that they’re trying to do. But what this proposal does is it challenges exactly that idea that you said that when we see objects that seem to be located in different parts of space, we really do have two distinct existences, so to speak, so that any independence in between those dates must be explained by some causal interaction or some sort of signal passing between them What this proposal does is it undermines that. And that’s a much deeper sort of undermining, it doesn’t leave the ordinary structure of space time intact. It really, completely deconstruct.

Ken Taylor
Righ, so quantum mechanics at bottom is just really, really mind boggling. And, you know, it lets you configure that it lets in all this mystical stuff, but I don’t think that’s really true. But you know what, we’ve got callers on the line, John and Oakland on the line. Welcome to Philosophy Talk, John.

John
Hi, thanks. I’m enjoying your show a lot. And I’ve been reading about these kinds of theories for a while. And there’s a question that I’ve had that I hope your guests can illuminate some for me. And I’ve been wondering, if you do something really trivial, like say, I scratch my head, or I don’t scratch my head? Would you say that’s enough to create an entirely different universe, which is otherwise identical? Except I happen to scratch my head at one point? Or is that like not enough to create a whole nother universe to come into being?

John Perry
Well, that sounds like a question about the relevance of quantum physics for the problem of freewill. And I know Japan’s interested in that. So I’m really interested in your answer here.

Jenann Ismael
Hmm, I think we actually need to bring in freewill. I think it it’s partly a question for people who advocate in Everett interpretation where there really is this sort of splitting after measurement? And it’s a question about how ubiquitous those sorts of splittings are. And it’s actually much worse than even you suggest for the Everett theorists, they have to say that splitting is going on all the time, everywhere, so that every time there’s an observation or a measurement, there’s a splitting.

Ken Taylor
Wow. So let me let me ask a different question. So we’re part of a quantum, right, we’re ultimately built out of quantum stuff. But now the how is it that we see a world populated with middle sized dry goods, as I think you sometimes like to put it, and they don’t behave in these? They don’t seem to be Avon these ways, right? The state that you know, this computer, I don’t I don’t go to the other side of Alpha Centauri and fine, I might find some subatomic particle that I think, oh, that’s the same particle again, but I won’t find this computer again. And moreover, this computer seems to be contained in like a very tightly constrained space. How come middle sized dry goods don’t behave very quantum like if the whole world is made up of quantum stuff? Why is that?

Jenann Ismael
So one of the most interesting things that physics has taught us quite independently of quantum mechanics is that we can have these higher level structures stabilized out of low level interactions, where the high level structures look just very different than the low level interactions. So I think one of the examples that one of your colleagues mentioned was the idea of solidity. So things are solid, you know, at the macroscopic level, but when we look behind the scenes, we see a lot of complicated activity and lots of empty space.

Ken Taylor
That’s true, but we can understand the appearance of, you know, space occupied everywhere, even though it’s in space isn’t occupied everywhere and supposedly solid, we can understand why it appears to us thusly. Are we? Are we at any way making any progress and understanding why the world appears to us in these, these chunks of middle sized dry goods that behave more classically than quantumly?

Jenann Ismael
Well, this is why I love this particular suggestion, that’s that, you know, comes from these examples of bone because there we do have concrete, easily describable almost perfect formal analogies for the what we want to say about what we actually see in ordinary 3d space. And the higher dimensional reality that one wants to describe that one wants to sort of say the quantum world is really like so think about the fish tank, of course, we do have an easily understandable relationship between the events that are going on in this three dimensional fish tank, and what someone who only sees the screen,

John Perry
Janina starting to see your theory as very conservative. That is to say, if we’re going to postulate something, try to understand quantum mechanics, rather than postulating a whole lot of universes with their own complicated objects. You just say, well, Quanta turn out to be identical. in ways we can’t see, because the identity shows up only in a dimension that’s not accessible to us. But it doesn’t doesn’t imply that people turn out to be identical along that dimension. And so what’s identical and non identical along that dimension really doesn’t matter too much to people. You mean, even if the quanta that I made out of have have each of them has a life somewhere else far away in the universe. They don’t have a life far away combined into me, so I don’t really need to worry about it. Except when I talk to people like you.

Ken Taylor
Does he have you right?

Jenann Ismael
That’s exactly right. I mean, it is a very, very conservative interpretation. It preserves locality. So objects, you know, don’t past funny signals across, you know, ad space like separation, it preserves the idea that things evolve continuously in time. And there are no spontaneous changes of state. It’s deterministic. So it is a very conservative interpretation. I think it’s very natural because so many of the other interpretations of quantum mechanics get tied in knots because they’re trying to explain in the space in which we see objects correlated, they’re trying to explain the interactions in terms of signals passing through that space.

Ken Taylor
On that note I’m going to thank you for joining us. It’s been a scintillating conversation.

Jenann Ismael
Thanks so much, again, for having me.

Ken Taylor
Our guest has been Jenann Ismael. She’s a professor of philosophy from the University of Arizona, author of “Essays on Symmetry” and “The Situated Self.” This conversation continues on our blog, the blog dot Philosophy Talk about O RG where our motto is Cogito ergo Blago, I think, therefore, I blog and you can also find out more by visiting our very active evergrowing Facebook page,

John Perry
And you can sign up to get the free weekly podcast of Philosophy Talk, website, Philosophy Talk dot o RG. For the final word, we’re going to stretch the bounds of space and time with Ian Shoales the Sixty-Second Philosopher.

Ian Shoales
Ian Shoales… When it comes to quantum physics, it’s hard for me to separate real science from New Age Whoo. Part of the problem is that math is not my strong point. I mean, I still don’t understand why we can’t divide by zero. Can somebody make that happen? I take my point of view from Niels Bohr who said, for those who are not shocked when they first come across quantum theory cannot possibly have understood as one who was both shocked and misunderstanding, I hope I can be forgiven and not quite getting our thing in the quantum world doesn’t achieve fitness until it’s observed. Or our second thing separated from first thing will need to become the opposite of the first thing, but only when observed. And there’s the Zeno Effect and what your thing, as long as it’s observed will not change space and time as we seem to know it don’t exist in the quantum world, at least not that we can observe so so chairs only a chair as long as they’re sitting on it, or their chair only comes into being when we decided to sit down. If the real world were like the quantum world, water would either be frozen or boiling, maybe both at once. It will be fast and stopped with no acceleration in between. If the real world were like the quantum world, for a few white car with airbags, it would immediately be a red car with pointy spike bags. And those things only be real, as long as we look at them. Nobody would drive because there’s either no place to go, or every place is the same at the same time, unless we’re not looking. All of this has led to a number of counterintuitive and alarming suppositions, among them. The universe is just a computer projection, or our entire universe actually exists in two dimensions which we only perceive as three. Or we actually live in a universe of 11 dimensions are the only reality is observer based. The moon only exists because we look at it. The many worlds theory supposes that for each possible outcome of any given action, the universe splits to accommodate it. Now that theory is cool with me. I like to think that in another world, I’m the mayor of Europe, I know pretty much everything my girlfriend has a lovely Jamaican accent and I can divide by zero until the cows come home. Not only that the cows come home fully cooked, falling off the bone delicious and are now officially reclassified on a subatomic level as vegetables. But only when we’re not looking. I gotta go.

Ken Taylor
The wisdom of the ages in a nutshell from Ian Shoales the Sixty-Second Philosopher.

John Perry
Philosophy Talk is a presentation of Ben Manilla productions and the trustees of Leland Stanford Junior University, copyright 2011.

Ken Taylor
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John Perry
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Ken Taylor
Also thanks to Chris Hoff, Merle Kessler, Dave Milar, Corey Goldman, and Mark Stone.

John Perry
Support for Philosophy Talk comes from the Templeton Foundation, and from various groups at Stanford University, the friends of Philosophy Talk…

Ken Taylor
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John Perry
The views expressed (or mis-expressed) on this program do not necessarily represent the opinions of Stanford University or of our other funders.

Ken Taylor
Not even when they’re true and reasonable. The conversation continues on our website, Philosophy Talk dot ORG.

John Perry
I’m John Perry.

Ken Taylor
And I’m Ken Taylor. Thank you for listening.

John Perry
And thank you for thinking.