IRA FLATOW: This is Science Friday. I’m Ira Flatow. I want you to try something. I want you to look around and observe the world around you for a second.

Me, I’m sitting here in the SciFri studios. There’s a mic in front of me, a table, right there. I have my scripts. I have my questions. I even have a glass of water. There you go.

Now think, what if all this stuff, all these objects, this space, this reality we live in is just an artifact of some underlying quantum structure? Could it be that space and matter and things, the only stuff we know, the only stuff that feels real are actually the exception and not the rule to the overarcing order of the universe. Or as one of my guest writes, when you stretch an arm to grasp a pencil and it’s just outside your reach, something is acting to thwart you, creating what you perceive as distance. And when we ask what that machinery could be, we have arrived at the outermost frontier of modern physics.

Now, this hour we’re going to be exploring that frontier of modern physics, to paraphrase Rod Serling, a land of both shadow and substance, of things and ideas, so fasten your seat belts. George Musser is the author of Spooky Action at a Distance, The Phenomenon That Reimagines Space and Time, and What It Means for Black Holes, the Big Bang, and Theories of Everything. And we have an excerpt at sciencefriday.com/spookyaction. He’s also a contributing editor at Scientific American and Nautilus magazine. Welcome to Science Friday, George.

GEORGE MUSSER: Thanks for having me.

IRA FLATOW: You’re very welcome. Also with us today is Shohini Ghose. She’s an associate professor of physics and computer science, and director of the Center for Women in Science at Wilfred Laurier University in Waterloo, Canada. Welcome to Science Friday.

SHOHINI GHOSE: Great to be here.

IRA FLATOW: Let me begin with George, first with a little experiment explanation of what the title of your book means, Spooky Action at a Distance. This was something that Einstein came up with, wasn’t it?

GEORGE MUSSER: Yeah. It was a thought experiment he did to explore some of the implications of quantum physics. And actually, he first began to figure out what this phenomenon was in 1909. It actually predates even his famous 1935 paper with Podolsky and Rosen, the EPR paper that everyone now cites.

And there’s a lot of different metaphors and ways you can think about it, but the way I like to think about it is coins, flipping magic coins. So you can prepare these coins together, usually it’s done with some kind of optical crystal. I could give you one coin and you would go home and keep it in your pocket. And I would keep one coin in my pocket.

And later that evening, maybe we would measure the coin. We would flip it and would see whether it comes up heads or tails. And that actually corresponds to different properties of these particles. And if I found it came up heads, you flipped your coin, it would come up heads too. If I flipped tails, you would get tails.

So there’s this kind of synchronicity between these two objects. And that’s really the phenomenon that Einstein was very troubled by. He thought it meant action at a distance, or what he called spooky action at a distance to kind of heighten its mystery.

IRA FLATOW: Right. And one of the great mysteries about it is that my coin and your coin could be separated the extent of the universe far apart, right?

GEORGE MUSSER: Other sides of the galactic empire. They could be anywhere, really.

IRA FLATOW: And they would know– they would flip at the exact same time. As you flipped your coin, my coin would flip.

GEORGE MUSSER: Exactly.

IRA FLATOW: And that’s why it’s such a spooky action.

GEORGE MUSSER: Exactly. It seems to just not be amenable to a mechanistic ordinary description, an ordinary explanation of it.

IRA FLATOW: Hmm. Shohini, one of the things you study in this is this spooky action at a distance called quantum entanglement. Is that what we’re talking about here?

SHOHINI GHOSE: That is. That is exactly what we’re talking about. And it is definitely very strange.

IRA FLATOW: Is it spooky to you?

SHOHINI GHOSE: It’s pretty spooky. I don’t think we understand the mechanism, so the theory actually is quite well tested, the theory of quantum physics. And every experiment we do seems to verify this mathematical structure, which is what we call a theory. So according to the theory, it’s very precise and absolutely perfectly mathematically logical and consistent. But what it actually means, the mechanism by which these particles are connected, that part we still are debating.

IRA FLATOW: Because in order to separate it that far, you have to go faster than the speed of light, right? The knowledge has to travel faster than the speed of light, George? Does it violate that, or does it not? And that’s the spooky part, that it does not?

GEORGE MUSSER: Well, Einstein’s concern was precisely that, yes, it violated or it needed, I should say, to violate. So we have to kind of separate a couple levels here. First we have this phenomenon, at the time of Einstein’s paper, it was theorized out of the theory, but we’ve since observed it.

And then we have to ask, how do we interpret the phenomenon? And that’s where we get into, oh, god. Do we need to have something going faster than light, because the particles in question could be light. They could be flying apart from each other at the speed of light, in which case to catch up with them, you’d have to move faster than light. So that is a problem, because if you accept relativity theory, and Einstein, having invented relativity theory, certainly did, that would seem to violate his principle that or his implication of the theory that nothing can out-run light.

Now, I think the thinking today is it’s probably not an issue. For one thing, you can’t use this spooky connection to transmit information or exert some kind of causal influence of one place on the other. You can’t build an ansible or a subspace radio or one of these science fiction-y types of devices with it. So probably it’s more subtle. It’s probably not an overt violation of relativity theory or this going faster than light question. It’s more subtle. It’s indicating something deeper about space and time.

IRA FLATOW: Yeah. Well, I want to get into that. Shohini, how do we actually observe this in real life?

SHOHINI GHOSE: So there’s been a lot of experiments in recent years, starting from I’d say around the ’80s people started really getting interested in this idea. And typically in order to generate these kinds of entangled particles, what’s done is you shine laser light on a nonlinear crystal. And every once in a while, one of the incoming particles of light, which is called a photon, will generate pairs of photons. And those photons are entangled in some property that they have, specifically polarization. So there’s different polarizations of light. So both photons will come out either jointly being horizontally polarized, or both being vertically polarized.

Now, what’s weird about it is that we don’t think of it as, oh, like a regular coin where we know that it’s either heads or tails, it’s just that if you don’t look, you don’t know. No. In the case of the photons, the way we have to think about it in the quantum level is that they’re both horizontal and vertical polarized at the same time. So if we only look at one of the particles, there’s really no information, because there’s sort of this probabilistic description. There’s a 50% chance that it’s horizontally polarized, 50% of the chance it’s vertically polarized.

However, what we know for sure, and this is the power of this entanglement, is that if we measure one of the photons to be horizontal, the other one is instantly horizontal as well, or vice versa. So that’s how the experiments are done. You can actually generate these polarized photons and then detect them and, yeah, build statistics.

IRA FLATOW: George, you say in your book, I’m going to quote this, “when we can no longer take space for granted,” I mean is spooky action at a distance possible because the distances between the objects really don’t exist in another– in other words, the spooky action may be happening in another realm of physics we’re not aware of, so the objects are really not separated so they can happen right like they’re next to each other? Space, the way we think about it, is not real. Am I over-simplifying that, because it’s Rod Serling talking to me.

GEORGE MUSSER: It really does sound like Rod Serling. I love the old Twilight Zone episodes, and it does sound like something out of them. Again, scientific honesty requires me to say that I’m just presenting a certain interpretation. There are other alternative interpretations. But yes, the proposition that I’m defending in this particular book is that the particles are acting as though they are not separated by distance, or acting as though they’re actually co-located and there’s no ginormous gap between them, and that that could be an explanation for why they can behave in unison, as they seem to.

IRA FLATOW: And so space may be the exception, not the rule, as you write. Most proposed unified theories of physics suggest that the vast majority of the universe’s possible states are non-spatial.

GEORGE MUSSER: Yeah.

IRA FLATOW: We’ve constructed space for our own convenience, or it pops out of the mathematics.

GEORGE MUSSER: Yeah. I don’t think we humans can take credit for having constructed space. I mean, that would be a great accomplishment if you could do that. No, the universe has somehow arranged itself such that it has this kind of spatial-temporal structure to it, and that’s the mystery.

And this is where the whole entanglement question and other types of non-locality we see in physics intersects with the search for a unified theory of physics. So the type of stuff that Carlo Revelli works on in loop quantum gravity, Brian Greene’s work in string theory, and others, out of those theories comes the idea that space is a construction. It’s built like LEGOs, like dumping a bunch of LEGOs on your floor and piecing them all together and, hey, space. But if you can do that, as you say, then I could piece those same LEGOs together and get something not space. And your kind of imagination begins to just rebel at that point. Whoa. What could not-space be? What could the absence of space be?

IRA FLATOW: Shohini, what is the absence? How can we have the absence of space?

SHOHINI GHOSE: That’s a really good question. In fact, I’ll go one further and bring into this discussion not just space, but what we consider reality, because in fact, quantum physics tells us through things like entanglement and other very strange properties that our description, this model may not actually have anything to do with what we would describe as reality. So far, all of physics has been about trying to explain this real universe around us. But now we have a theory where if we try to ascribe reality to it, that particular reality either is very strange, where everything is connected non-locally, or if we want to preserve locality, then there is not even a reality until we observe something or do something.

So I think we are sort of having to rethink even this notion of what we perceive, whether or not it is actually related to just information and our senses, or is it actually connected to something that we call reality at all? So yeah, it’s a surprising way to have to go back and rethink what even physics is all about. Maybe this particular theory is just our description, it’s an information theoretic view, where we say, this is only our description of what we can observe. It tells us nothing about what’s really happening, perhaps.

IRA FLATOW: Wow.

SHOHINI GHOSE: I’ll leave it there.

IRA FLATOW: That’s starting less than zero, if it tells us nothing about what’s really happening. Isn’t that the whole idea of physics, is to find out how nature works?

SHOHINI GHOSE: Exactly.

IRA FLATOW: And if this tells us nothing, where has that gotten us? I mean, it’s more like we’re into philosophy then.

SHOHINI GHOSE: Absolutely.

GEORGE MUSSER: And physics often is– I mean, and it should be, foundational physics is at the intersection of metaphysics and physics. It’s kind of at that boundary. And so these questions should seem philosophical to us. And in fact, we have to bring all the apparatus not just of experimental and mathematical physics, but of philosophy to try to understand it.

IRA FLATOW: Hmm. It’s amazing. If you’re joining us, I’m talking with George Musser, author of Spooky Action at a Distance, a really good book. I’ve read a lot of– I don’t know how you got all of this together in one spot and did this, George. Also Shohini Ghose, associate professor of physics and computer science, director for the Center for Women in Science at the Wilfred Laurier University in Waterloo, Canada.

And you’re listening to Science Friday from PRI, Public Radio International. Talking more about– you know, what I want? I read the book about physics and you tell great personal stories in the book, George. It seems to me that physics really is a personal thing, that scientists who study physics put their whole body and soul into believing what they’re doing.

GEORGE MUSSER: Oh, yeah. I mean, this is why they’re doing physics as opposed to any of the other things we can do in life, just like an artist or really anybody who’s engaged in their profession will throw themself into it. And isn’t that one of the great joys of life to have that privilege to do that? And I think in the case of non-locality and these quantum entanglement and other types of questions, because they’re at the cutting edge, they demand the full person. They demand the full involvement of all our faculties in trying to understand these questions.

IRA FLATOW: Shohini, do physicists need big egos to do what they’re doing?

SHOHINI GHOSE: Well, actually it’s quite the opposite, I think. We are constantly humbled by how little we know. And that becomes a passion, to say, you know, there’s so much more to know. And the ultimate mystery is the mystery of how this universe works, so I think what the main driver I would say for myself for sure and a lot of my colleagues is curiosity. It’s about finding out about the universe.

And in order to do that, absolutely you have to have passion. And you absolutely have to be willing to actually fail, so there’s a lot of failure involved in doing this kind of work, because you have to follow these paths to the very end and see maybe you are on the wrong track, you don’t know what you’re going to find. So you have to be willing to step back and give up at some point and try different routes. So it’s absolutely something that needs a lot of commitment, for sure. And there’s absolutely a sense of achievement when you do succeed for sure. So in that sense, yeah, that’s good for our egos.

IRA FLATOW: Yeah. Well, George writes in his book, plenty of the greatest advances have their origins in wrong ideas, which breathes life into ideas by what it provokes.

SHOHINI GHOSE: Absolutely. I think this is physics by accident it what we call it. It’s a really, really important approach to doing physics.

IRA FLATOW: So failure is an option in physics.

SHOHINI GHOSE: Absolutely.

IRA FLATOW: Sort of.

GEORGE MUSSER: Yeah. I think the thing about error and failure is I think it introduces novelty into what we do, because otherwise we’re just stuck in our rut, so you almost need a mistake. And this is how natural selection works in the biological world and I think something similar happens in the intellectual world as well.

IRA FLATOW: Is physics stuck now, because it can’t explain this? There’s no unified– I mean, are we at a plateau where we need either new physics or a new idea that’ll talk about how these spooky action– what’s the mechanism, how it works? We know that it works, but we don’t know how it works.

GEORGE MUSSER: It’s hard to say. I mean, it’s something we’ll know really only in retrospect, I suppose. On the one hand, there’s just a burbling of ideas. It’s very exciting to go to conferences and hear people excitedly talk about their ideas and wow, let’s go have coffee and talk about your idea. And it’s such a great to and fro that’s occurring.

But I will say that I do get the sense that the physicists need some new input. It could either be an Einstein arising and piecing together things people hadn’t seen before that were there but hadn’t been appreciated. Or maybe even better, nature has to give us guidance. We need some experiment. We need something that’s actually just knocking us on the head and saying, hey, guys, here’s a new one data point or here’s a new experiment or here’s a new observation that is really going to guide us forward.

IRA FLATOW: Maybe some particle coming out of the Large Hadron Collider or something like that.

GEORGE MUSSER: We can only hope. Definitely.

IRA FLATOW: All right. Shohini, you agree? I got about 30 seconds before the break.

SHOHINI GHOSE: Yeah.

IRA FLATOW: Yeah?

SHOHINI GHOSE: Yeah. I think that’s certainly true, that there’s a lot of different aspects that we’re still exploring. And keep in mind that, yes, we’ve had quantum physics since the beginning of the 20th century, but that’s still about 100 years, whereas we’ve had older theories that have lasted centuries before that new idea came along. So maybe we’re still– this is early days.

And I agree that we need more data. And I think we are getting more data from cosmology, from LHC and elsewhere. It’s exciting times, actually.

IRA FLATOW: Yeah. We’ve got more data coming in from our phone calls. Our number 844-724-8255 if you’d like to join the discussion. You can also tweet us at SciFri. We’re going to take a break and come back and talk lots more with Shohini Ghose and George Musser, author of Spooky Action at a Distance. Stay with us. We’ll be right back after this break.

This is Science Friday. I’m Ira Flatow. We’re talking this hour about the spooky, weird world of quantum physics, with my guests Shohini Ghose, associate professor of physics and computer science, and director of the Center for Women in Science at Wilfred Laurier University in Waterloo, Canada; George Musser, author of Spooky Action at a Distance, and we have an excerpt of his book on our website at sciencefriday.com/spookyaction.

And I want to bring one another guest now, who’s built a computer game that lets me, you, anybody participate in a quantum physics experiment, no degree required. I have played this game online. It is addictive. And it’s quite easy. But it’s hard, so to speak.

Jacob Sherson is director of the Interdisciplinary Center at Aarhus University in Denmark and associate professor of quantum physics there. Welcome to Science Friday.

JACOB SHERSON: Thank you very much. Hi.

IRA FLATOW: I want to tell our listeners that if you want to play the game, you can check it out at scienceathome.org. Jacob, tell us why you’re enlisting the help of the masses here. What are you trying to pull off exactly?

JACOB SHERSON: I’m an experimentalist physicist, and I’m trying to build something called a quantum computer. And in this quantum computer, we have to be able to pick up individual atoms– and atoms, as you have talked about, wavy things, so that means that as we try to pick them up, they actually start to slosh when we move them around, so they start to move around just like a cup of coffee would move when you start to move quickly with it.

IRA FLATOW: And so as I play the game, you have to move the atom from one place to another and it is sloshing, right? And you have to keep it from sloshing out of the spot like the coffee would go over the top. It’s not easy.

JACOB SHERSON: Exactly. And after having moved the atom, if it’s still sloshing, then our quantum computation will give the wrong results. So our basic problem was I’m building the experiment, we don’t have any solutions on how to move these atoms around. Our best computers have failed at finding solutions for us. So in our desperation, we turn to something completely new, gamification of quantum physics.

IRA FLATOW: So you think people are better than computers at solving your problem?

JACOB SHERSON: Well, initially I didn’t think so. I just thought that was the last option we had and it would be a lot of fun trying it out. Now I’ve been so much surprised by reality and how good the players have been, and that’s exactly what we reported in Nature two weeks ago now.

IRA FLATOW: And you said you think this game allows people to use their so-called quantum intuition built into us.

JACOB SHERSON: Yes.

IRA FLATOW: What do you mean by that?

JACOB SHERSON: Well, I think that– so you’ve just talked about how weird quantum physics is. And that means that you sometimes sort of give up trying to understand quantum physics, which means that people tell me that I’m crazy because I want to enlist the help of normal people, because you cannot understand it. But in games, you actually don’t have to really rationally understand what you’re doing. You just have to get a sense of the rules of the game, and then you will, just by your intuition and your desire to do well in the game, you’ll actually just do well. You’ll start to take advantage of these subtleties and oddities of quantum physics.

IRA FLATOW: Shohini Ghose, what do you make of this computer game, the fact that humans can solve these quantum problems faster than machines?

SHOHINI GHOSE: This is so cool. It’s such a great idea. You know, this reminds me of when I teach first-year physics in my classes, Newton’s laws, when we get into that stuff, that’s quite challenging to a lot of students. And I usually tell them, you know, when you’re walking, jumping, running, playing, your body already knows Newton’s laws. It’s not like you have to stop and then calculate all of the forces and then start walking. Your mind already does this unconsciously.

So this is reminding me of that same thing, where there are obviously some unconscious ways that we can recognize patterns. And in this case, for this specific task it seems to be a really interesting, novel way of solving this problem, which our standard programming of computers doesn’t seem to get in the same way. So who knows what the possibilities are?

IRA FLATOW: George, you’ve played the game?

GEORGE MUSSER: I have indeed. It is like carrying a cup of coffee across the room, which I never was very good at, so I haven’t probably got the highest score. But it’s fun to play. And it also fits into what I think I’ve been trying to do over the years, as Shohini has, and that’s bring quantum physics down to the human, everyday level. And I think you can do that. You can actually almost, if you know how to look, see quantum phenomena all around us.

IRA FLATOW: I’ll get into that a little bit later, I want to say goodbye and thank you. Jacob, how many people do you need to play this game for it to help you?

JACOB SHERSON: That’s a fantastic question. We had 10,000 people playing for the Nature results that we published two weeks ago. Since then, 100,000 people have come in and played the games. And we’re just excited to every day plot the results of these new players.

And we just every day, day by day, we move the boundary of how good solutions players can find. So what is the ultimate limit? We thought that the ultimate limit was way much worse a year ago, so we’re just waiting anxious to see when people come in and play and give us better results.

IRA FLATOW: Well, I think we might be able to send a couple more people your way listening to our audience of 2 million here might be able to go over and play your game. Hope we don’t melt your server. The game is– check it out at scienceathome.org. Jacob Sherson, thank you for taking time to be with us today, and good luck to you on your game.

JACOB SHERSON: Thank you very much.

IRA FLATOW: Jacob is director of the Interdisciplinary Center at Aarhus University in Denmark, and associate professor of quantum physics there. Still with me are Shohini Ghose and George Musser. George is author of Spooky Action at a Distance.

We have lots of folks who want to ask questions, because this is such a difficult concept to grasp. So let me see if I can get a couple of things here, a couple of people on the air out of the way. Where should we go? OK. Let’s go to Alabama, Opelika, Alabama. Robert, welcome to Science Friday.

ROBERT: Oh, hi. Thanks. Great program.

IRA FLATOW: Thank you.

ROBERT: Here’s my comment. Regarding this heads/tails metaphor that you have for the coins, it seems to me you can only make this claim that once they’re correlated, a measurement of heads on one side gives another measurement of heads on the other side no matter how distant, the only way you can make that claim is if you can be sure that there hasn’t been an interaction with a third body in the meantime. And so it seems to me these claims are rather extravagant, because you say, well, even across the universe, once this one is flipped, the other one is flipped and bound to get the same result. That would be difficult to prove.

IRA FLATOW: You’ve hit the nail right on the head, I think, in the question that we’re facing. Isn’t that right, Shohini?

SHOHINI GHOSE: Yes and no. So it’s a very good point that if you have other things, like the environment or other particles, that interact with these two entangled particles, that has a huge impact. In fact, usually it will completely destroy that connection. It’s a process that we call decoherence.

So in fact, we would know if something like this happened, because when we do the experiment and we try to correlate the measurements of heads and tails, we would find that they don’t actually match up. So that’s how we would know that there has been something else that is impacting this experiment.

IRA FLATOW: But the fact, George, that there is nothing else impacting the experiment leaves open the question of how is it happening?

GEORGE MUSSER: Well, exactly right. I mean, one word, Robert, to focus on is the word “in the meantime” or phrase “in the meantime.” Often in these experiments, there is no meantime. As Ira was saying earlier, these experiments are conducted at complete the same time, simultaneous with one another, so there’s no time for any putative mechanism to transmit that influence.

IRA FLATOW: Could that mean– and I said this before, but it seems to me a logical solution, as you mentioned in your book, is that they’re really not separate, is that distance is our own concept but it may be another dimension somewhere where they’re not separated and they’re communicating.

GEORGE MUSSER: Yeah. And I want to emphasize this isn’t the first thing you would leap to in your– you would go to something exactly what Robert’s saying. You’d look for a more prosaic explanation for it. And they did. And for decades they have been looking and looking and looking, and then ruling out, crossing out all the ideas on their experimental lab book list. And they’re kind of driven to these extravagant options.

IRA FLATOW: Yeah. Shohini, you agree?

SHOHINI GHOSE: Yeah, absolutely. I think everybody who actually works in the field, in quantum physics hopes one day we will find some evidence that will allow us to actually move away from this theory, because it’s so weird. But so far, we haven’t. We’ve been trying, as George said. We’ve been trying to figure out a commonsense way of understanding things. And we haven’t got there.

On the other hand, we are very careful about making sure that there really is something weird there and that it’s not just all in our heads or just weird math. So for example, yes, we know for sure that we cannot communicate faster than light using this entanglement. We’ve been able to show that, test it, also mathematically prove it.

However, that doesn’t mean we can’t do other tasks. We can actually set up scenarios, kind of like games that you can play, where Alice has one of the particles and Bob has another one of these entangled particles. And then we can set up some kind of game with some winning strategies and try to figure out if these particles will help Alice and Bob win more than if there was no entanglement. And it turns out you can in fact do things better than you can without entanglement.

So it’s absolutely a real thing. It’s not just some strange thing that we can ignore. It’s definitely been tested in many ways.

IRA FLATOW: Let’s go to the phones, to Ocean Pines, Maryland. Dan, hi. Welcome to Science Friday

DAN: Hi. Thank you so much for having me on, Ira. I love your show.

IRA FLATOW: Thank you.

DAN: It’s fantastic. Thank you so much for doing it. Real quick, I missed the very beginning of the program, so I apologize if I sound crazy. Doesn’t spooky action require free will? And if there is no free will, isn’t it possible that there’s something like super-determinism that exists? I think Gerard ‘t Hooft– and I probably mispronounced his name– but I think he postulated that there’s a super-determinism in the physics underlying quantum that we don’t understand yet. Is that something that’s possible?

IRA FLATOW: George, you’re shaking sort of your head a little bit?

GEORGE MUSSER: Yeah, I mean, this is actually– I talked to t’ Hooft at great length about it and actually discuss that in the book a little bit. And it is an option.

IRA FLATOW: Explain that a little to our audience.

GEORGE MUSSER: So the idea is that– I mean, one way to explain in a prosaic way the outcomes of these experiments is that the particles somehow know what is going to happen to them. They have some kind of– you could think of it almost as like clairvoyance of that outcome. Now, you don’t really think it’s clairvoyance. You begin to wonder, well, how could they know?

Well, they could cheat. Someone could have slipped them the answer in advance. And that’s kind of what super-determinism does. It says that what’s happening in the detectors or the precursors of those detectors is somehow correlated with what is going on in the act of creating the particle. So there’s something like a common cause that’s accounting for the outcomes that we see. And you would have to trace that common cause way back, certainly before the experiment was conducted and probably right back to the origins of the universe, so somehow the universe was set up in a way that although the Earth didn’t exist yet, those particles when they met on that place called Earth would exhibit these correlations.

So it’s kind of this weird conspiratorial explanation for it. But it is in principle possible. And there are experiments to try to at least push how far back you’d have to have the conspiracy to do that.

IRA FLATOW: This is Science Friday from PRI, Public Radio International. I’m Ira Flatow talking about quantum physics with Shohini Ghose and George Musser, author of Spooky Action at a Distance.

We have just a few minutes left, but I want to get into something that’s really central in your book we haven’t talked about, and that is black holes. Black holes, you say in your book, is the opposite of the Big Bang theory, where everything gets sucked in as if exploding.

GEORGE MUSSER: Well, I wouldn’t say it’s opposite of the Big Bang theory.

IRA FLATOW: The Big Bang?

GEORGE MUSSER: In a sense, it’s the opposite of the Big Bang, because the Big Bang, everything kind of went away from it in a way. I mean, we had to modify that, but you can think of it as an explosion outwards in some sense. And the black hole is kind of the opposite. Things are going into it.

But here’s the thing about black holes. We know they’re weird. We know you die. All the things about black holes that you see in science fiction are all based in theory.

But they’re also the number one test case we have in contemporary physics for a quantum theory of gravity. They’re the thing that actually you invent a quantum theory of gravity to try to explain, because they involve various paradoxes that Stephen Hawking really made his name discovering. And one implication of the theory that I’m putting forward in the book is that the black hole may actually represent kind of a boundary to space or maybe even to space and time. In a sense space and time melt inside a black hole and they transform into some new phase. Just as an ice cube might melt and form water, something like that may happen in a black hole too.

IRA FLATOW: And what happens to all the information that gets sucked in to the black hole?

GEORGE MUSSER: Well, that is exactly the issue here. And that’s actually why people are driven to this seemingly odd view of black holes as a melting of space-time, to preserve the information, because as far as we can tell, that is a sacrosanct principle in the natural world, is that information is preserved, which is– by the way, to really think about it, I like to think about it is everything in the world is reversible. If I make something, I can break it. If I can go left, I can go right.

And the black hole also should be reversible. Things that fall in should be able to come out in some form or other. And in order to make that possible, in order to preserve the information in those objects, maybe you need some new form of matter to do that.

IRA FLATOW: Which we don’t know about.

GEORGE MUSSER: We do not know about. And in fact, you kind of don’t want to know about it, because you’d have to fall into a black hole to discover it, yeah.

IRA FLATOW: Shohini, how do you wrap your head around all of this stuff, black holes?

SHOHINI GHOSE: It’s definitely a challenge to do that. But yeah, I agree with George that the way physics progresses is when we find an exception to our model, something where we cannot explain what we see. And black holes are exactly that, because a black hole is an object which is predicted for massive objects by general relativity, so that is where we expect the laws of gravity to work, which is basically relativity at work.

However, if you talk about what’s happening inside the black hole, we assume that all of this mass is acting at very, very microscopic scales. But that’s where we have to apply the laws of quantum physics. So this is why black holes are this very, very special thing, where we need to be able to apply two different laws and we don’t know how to make them fit.

So it’s exactly this example of something outside of our physics, and that’s why it’s so interesting, because that will help us modify our theories. If we can observe, for example, radiation from a black hole, that will tell us more about what’s happening in terms of information loss as George mentioned. However, of course, that’s a very challenging thing to do, but not impossible.

IRA FLATOW: We’re going to talk lots more about this, because this is a fascinating topic and it takes more than one hour of Science Friday. I want to thank George Musser, author of Spooky Action at a Distance. We have an excerpt of his book on our website at sciencefriday.com/spookyaction. And Shohini Ghose, who is director of the Center for Women in Science at Wilfred Laurier University in Waterloo, Canada. Thank you both for taking time to be with us today.

And on our website, if you want to investigate this hidden particle world at home, you can make your very own particle detector. We have a cloud chamber up there. Check out the experiment at sciencefriday.com/cloudchamber.

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