talks

Discussing Time’s Tattarrattat

Posted on: September 9th, 2015 by libby

Tonight I'll be giving a talk about my recent project Time's Tattarrattat at the Creative Data Club at the Ace Hotel in Shoreditch.  While I have written a short blog post about the project already, my collaborator and I managed to record a discussion in Turku about the science, philosophy and the process we went through while working on this art and science collaboration.   If you would like more insight into our work keep reading below.

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Libby and John chat about Time’s Tattarrattat

Libby: So John tell me a bit about yourself, obviously I know you pretty well.

John: [laughs] Well I’m an Irish researcher based in Italy in theoretical physics and my work basically spans I guess interests in quantum physics, many body physics, statistical mechanics and particularly focusing on thermodynamics of quantum systems at the moment.

Libby: So let's talk about the work we've done this week!

John: Yes an interesting project! Well there's this arts festival here in Turku, Abo-a-gora, it's always difficult in Finnish no?

Libby: Yes, Aboagora.

John: Which was an idea by Professor Sabrina Maniscalco and is basically an interface between the arts and quantum physics, but I guess more generally research in physics and the [more specific] stuff that we do.  Is there a way to represent what we do as scientists through the medium of art or can art add even more to the description of scientific concepts?

Libby:  Yes you set me up with Sabrina in London.

John:  Yes, that's right.  Well I mean Sabrina is someone who is very dynamic and active in these things and I knew that she's very much interested in outreach and doing kind of ambitious projects, and I thought given your background in physics yourself that it'd be only natural to put you two in contact.  I guess that's where it has started from - she had the idea to put the two of us together to do this thing, which is something I didn't envisage, given that I have collaborated with you as a scientist before and I genuinely didn't think that once you had left science and went into art that I'd collaborate with you again. But it happened! It's kind of funny you know.

Libby:  We've got some sort of gravitational pull.

John:  [laughs] That's it like.

Libby: The idea for this arts jam was that we have thirty minutes to make some sort of interactive performance, an installation that responded to a topic that we chose.  In the end we went for the idea of time.  So we chose a really easy problem there.

John: [laughs] Yeah it's probably the most difficult one in physics.

Libby: I was driving for something else initially, I remember I wanted to focus on complexity, what drew you to this?

John:  Yes, because I find complexity in physics a vague concept in general and I think you know, it's almost TOO vague for me.

Libby: But time is such a big topic as well.

John:  It's a big topic but at least it's a specific topic and we chose in particular to focus on the thermodynamic arrow of time and the second law.

Libby: So what interests you about the second law?

John: So I suppose at a scientific level for me the second law of thermodynamics is one of the, if not THE most interesting laws in physics. It is really amazing how all other physical theories must obey this law. It governs things at vastly different scales from galaxies to your refrigerator. In some sense it’s really an example of an emergent law meaning that it emerges from the microscopic behavior of the atomic world and manifests itself in our macroscopic world.

Libby:  Can you just tell us what the second law is in a really simple way?

John:  Well this is one of the interesting things about it because the second law of thermodynamics is something that you can state a number of different ways.  For instance, one of the ways you can state it is well 'heat can never flow from a cold place to a hot place.  The Kelvin statement of the second law is that, you know: 'no work can be extracted from a single heat bath in a cyclical process”. Also you can state it by saying things get more disordered or that entropy tends to increase.

Libby:  By work you mean that a mechanical system can push something.

John:  Exactly.  Work is something you either do on something or you “extract” it like in an engine. You need two baths, a hot and a cold one, to make an engine, but you cannot do it from one bath. In fact, this idea of thinking about engines led to thermodynamics in the first place. Carnot, a French military engineer, worked out that heat engines were limited by a fundamental relation, which links the efficiency of an engine to the ratio of the temperature of the baths – this is the second law in action. What is quite amazing is that this holds irrespective of what you make the engine from – so it’s truly universal!

Libby:  And this would be like a car engine.

John:  Almost. A car engine that runs at the efficiency of Carnot would be useless. One of the assumptions that Carnot made was that the strokes were done so slowly that no friction or excess heat is generated. This excess heat is known as entropy production and it basically decreases the efficiency – nevertheless you gain power at this expense. You oil your car to try to reduce the frictional effect. With more power, you can extract more work from your engine. Engines that run at the maximum Carnot efficiency are practically useless, as they have no power.

Libby:  Entropy production sounds technical and complicated.  We have no intuition for it.

John: So loosely speaking, you can say that in any particular system, the tendency of that system is to go from an ordered state with low entropy to a disordered state with high entropy. Your bedroom does not become tidy by its own accord, eggs do not unscramble and you do not get younger. The real world we live in is what we call ‘out of equilibrium’ but everything around, including ourselves, seems to evolve to reach the state of maximum entropy. This is very deep, but amazingly the principle is like that of the engine – everything around us produces entropy from car engines to your central nervous system .  All of our life we are struggling against equilibration – to live we have to stay away from equilibrium, we have to stop ourselves reaching the same temperature as the surroundings – in the process we are producing entropy. Whether you are in Finland in winter or Italy in summer – your body has to work hard to stay at the same temperature through marvelous control techniques that produce entropy. When these stop working – well – its over.

Libby:  How does this relate to time then?

John: This production of entropy leads us to the emergence of what's called 'time's arrow'.  The idea of a time's arrow, a direction in time, is something you're probably familiar with because you see things getting older, you're getting older yourself, you don't get younger.  There is a certain directionality associated with time.  And how and why is that emerging?  Because in physics, basically all the microscopic laws, the laws of the individual constituents are basically time reversible – there is no reason for us to have some directionality with time, but we absolutely experience this sensation of time passing. Irreversible processes are ones that produce entropy – these seem to have a strong causal imprint, but crucially the issue of time’s arrow seems to be due to a low entropy initial state. Which in my opinion is still mysterious.
Libby:  Okay, does is mean that the laws of physics are time reversible?  Does it mean that time can flow backwards if we can engineer the system correctly?

John: In principle there's no reason from the primordial physical laws, so the mechanical laws, the quantum mechanical laws.  They run equally well in reverse as they do in the forward direction.
Libby: So could there be some sections of the universe where time is running backwards natually?

John: There could be, I mean who knows.

Libby: Or like a parallel universe, where time went from zero to minus our time....

John: Well we're already skipping ahead quite a lot, but I mean it's an interesting question.  Why is it that we see time going in THAT direction in our universe?  And probably, you know, one why that you can address it, skipping over a lot of stuff, is it seems to be very crucial that the universe did start in a very low entropy state.  And there's no per se reason why this is the case.

Libby:  So a low entropy state means a highly ordered state. And we don't know how that occurred?

John: Not really, there's some speculation.  You might see some more risky statements like it's due to gravity and all that.  But in the end, there's no real, particular definitive proof that's the case.  You can speculate and it's interesting and it's still very much a topic of interest for cosmologists etc as to why the universe began in such a low entropy state.

Libby:  Absolutely, it's fascinating.  I remember when we first started our initial discussions and I was trying to imagine or I asked us, actually, to both write down some ideas about what it would be like to experience time running backwards, but when I started to think more deeply about this, it kind of just killed my mind.  I mean, it was like you kind of regress back to thinking about the start of the universe, because ultimately you cannot even think about time running backwards here on earth unless you go right back to the start.  But then it's like how would time running backward even look?  I was thinking about quantum physics, if you could do an experiment where time run backwards could you ever observe it?  And it is such a hard thing to think about, even for someone who was used to thinking abut physics problems in some sense.

John:  Yeah, I remember when you had the old VHS video tapes, if you remember when you were a kid, watching ET or whatever.  I mean, I remember when you, what you have to envisage is a situation whereby you press rewind on the video and then you watch it, like you would watch it in the normal direction and it looks so bizarre.  The weird thing is that what's normal in reverse can be highly abnormal in the forward direction. Think about it!   Definitely it is a difficult thing to think about, because we're just so conditioned in our lives to thinking about the past running into the future through an ephemeral present.  It's an interesting concept to play with and I guess it's interesting concept to play around with as an artist.

Libby:  Yes, well visually or aesthetically, in some sense it's like thinking about how disorder goes to order, in terms of pattern making in particularly, and also how that would make us feel, as you say, this is a highly unusual thing to see.  Also imagine if there was some way of locally going back in time and then all of these strange things could occur.  For instance, you could meet your mom before you were born.  Well this is time travel, which is somewhat different and it's been discussed in science fiction a lot.

John:   and you could get a glass of whiskey and it spontaneously forms ice cubes, and these types of things that are very strange events in the real world.

Libby:  [laughs] Absolutely.  So after our first conversation, you mentioned some really nice, interesting visual imagery from, was it Kelvin's paper, about waterfalls running backwards.

John:  Yes right, actually this arrow of time issue, even though it arose in the early twentieth century, it had been around for a while.  People were kind of questioning what would happen if the time arrow ran backwards and one of these was an influential paper by Kelvin. I guess it was in the 1870s, I could be wrong there, to Nature [journal] actually whereby he talks about the irreversible process, dissipation and what would happen. He had these beautiful things - if we could reverse all of the molecules in the universe then we see the waterfall coming back from the bottom of the river back up the top.  It's a very beautifully written piece and actually it has a lot in it already.

Libby: Are there illustrations?

John:  There are no illustrations, but it's really beautifully written though.

Libby: It sounds like an Escher drawing.

John: Exactly.  But [Kelvin] was well aware of the issues like irreversibility and etc and there were many other big name scientists at the time were worrying about these things.  There was Boltzmann, Maxwell, all of these great scientists were wondering what would happen if you could hypothetically reverse time.

Libby:   You were saying to imagine a reversing a gas expanding. You would need to change all the momentum coordinates of all particles.  In principle could you do this for all particles?

John:  Some people like to appeal to information theory to explain time and irreversible behavior. Its an interesting perspective – the intuition would be that somehow irreversible processes (like entropy production) are not fundamentally irreversible in the sense that they could be made reversible if we actually could compute every thing about our system. What you are getting at there is something, which is a well-known paradox in physics, which is the so-called Maxwell demon paradox.  And what that is, is that imagine you were some sort of super intelligent being in the sense that you could know all the particles positions and velocities and simply reverse the dynamics by really swift manipulation. Its very difficult to do this because there is not the computing power in the universe available to achieve such a task for gases which contain 10^23 atoms. In this view you could see time as emerging out of a kind of computational complexity.

Libby:  Can you clarify exactly what you mean by computer power.  What would a computer need to be doing?

John: Well it would need to monitor the velocity of each individual molecule at the one time and be able to then reverse the sign.

Libby: Constantly as well?

John: Constantly, yes.  That's a HUGE computational task.

Libby: I suppose you would need more bits than the number of atoms in the room.

John: Exactly.  And you would need a memory basically. In the simplest situation you would need the demon to basically know what's going on at all times in order for him to perform this time reversal.

Libby:  So in some sense could the demon be what some people would call God, because he has this overview of everything?

John: [laughs] I dont know about that …....
Libby:  [laughs] So of course this is impossible to do for the whole universe and is why time cannot run backwards...

John: Yes, exactly.  I mean I'm not a cosmologist and I don't know these things, but I remember listening to popular talks by cosmologists when they were talking about basically three possible scenarios for the end state of the universe. I'm not entirely sure, but I think the consensus now is that we started from a small point, we had the big bang and then the universe is expanding and expanding and at some point there was a debate as to which ending we have, depending on how much dark matter or energy there is in the universe, whether or not the universe would contract, keep going or reach a stationary state.  And I think, if it actually had this big crunch meaning that it went backwards, then we would actually live in world with time running backwards. I think the consensus is that it wont happen.  I'm wildly speculating about these things.

Libby: So this was the science and the ideas we were thinking about when we were working on this project.  Can you tell me a bit about the process?  What did you read and how was it to work with me?

John: In some sense, I probably had to work a bit harder to give the talk in the way I gave it, than I would normally for a standard physics talk.  For a number of reasons: Number 1 there was the interactive piece that you made that I guess we will talk about in a second.  Number 2 the audience there was going to be different than scientists, although there were scientists there.  They are people that are interested more in the arts and literature, in exploring different concepts, I was very conscientious when I made the talk, making it accurate, interesting, but not over the top and it was probably borderline [laughs], because I put a lot of philosophy in it as you saw.

Libby: I think you asked more questions than gave answers.

John:  Which is always good I think.

Libby:  It's like how good artwork should pose questions for the viewers.  Your talk was actually quite poetic.  You used a lot of imagery in your talk, for instance the trees.

John: Yes, exactly.  I mean even in literature, the liberal arts - it's not just science where time is an important topic - in philosophy.  Take literature, I think I used the example of how some novelists like to play on the perception of time like and I used the example of James Joyce from Finnegan's Wake when there's a scene with two women who are washing their clothes and as the night falls, if you read it it's really wonderful because you don't know what is happening, what's going on, in typical Joyce way.  Basically as the night progresses, these women sort of, well as you read it you realize they are starting to morph into something else, their communication starts to becomes something completely different and they basically change into a tree and stone and I always found that really fascinating.  It was really a play on time and the perception of time of the reader etc.  I used this thing to motivate my talk.  Time is such an important thing for the arts and literature etc.

Libby:  So for our Skype discussions throughout this project, did anything come from those discussions that helped to shape your views or contribute to your research?

John: They did! I knew a lot of the fundamental problems with the arguments and the philosophical issues that we have spoken about, but I really had to sharpen them, because at the end, if you give a talk, and you want to do your best job and you really think you know something, but when you have to explain it to bunch of people, you really, really have to know it.  I'm not saying I understood everything, but it definitely gave me a greater appreciation of the different viewpoints in this resolution of the thermodynamic arrow.  (If there is a problem with the thermodynamic arrow, some people would say there is not.)  So I understand the different strands of the argument and I think that was important for me.  Also it definitely gives your work more context.  When you're doing any creative process, it gives you more ideas, I thought about different things that I'd been working on, some ideas came to my mind - we talked a lot about macroscopic irreversibility and of course I'm a quantum physicist and it's no different there and I was thinking about how you can describe irreversible processes using quantum mechanics.  I have an idea now that was inspired by the piece, which is to try to construct a proper understanding of irreversible motion through a technical thing.  Anyway, it was the art piece that really inspired those feelings and ideas.

Libby: I think for me this project was really interesting because I never deeply studied thermodynamics again after my undergraduate although I knew the basics of course, but I have started to understand it in a deeper way.  It was really fascinating, as our conversations would go from hardcore science to philosophy to chatting more about the artwork.  I remember the conversation we had that was discussing the palindrome idea and how it could feed into the visual elements and then we started discussing random walks.  I liked how the discussions ranged a wide range of topics, before we eventually settled on some of the ideas that I finally used.  I think we were both excited by my palindrome idea and our dual agreement is what spurred me on to implement it.

John: What I thought about your palindrome idea was that it was clean and simple enough and at the same time it sort of evoked the spirit of the second law and the increasing of entropy of something and the beginning in a low entropy state.  Your work really had it's own thing to say about the second law, in my opinion.

Libby: What I liked was that my palindrome analysis, uses information in language.  While it is not the same sort of information you would have to gather up when reversing time, i.e. we spoke about this room full of gas molecules and Maxwell's demon. Well it's not that type of information, but it uses text and shows through words and through language that even this type of information has an intrinsic irreversibility.  My text analysis here are a very different thing, but it evokes that idea of Maxwell's demon.  In our initial discussion we spoke a lot about Maxwell's demon and this is what came out from it.  Due to the brief requiring interactivity, I some how had to extract some information from you!

John:  By the way, I planned to talk a lot more about Maxwell's demon and information processing in the performance, but in the end I got so much into the philosophical side of it, I almost cut out a good section of the science part, which is okay I think.

Libby: I think it's great to pose all the different questions that are being asked and then to allow the audience to take away what they want.

John:  It seemed afterwards from talking to certain people in the audience that they appreciated it, that they learned something from it and that is the most important thing for me as a scientist.  I don't know about you as an artist, but for me the fact that they learned something in a different way is really wonderful you know.

Libby: I suppose as an artist, I don't really mind if someone loves or hates my work, but I would like them to feel something.  It doesn't necessarily need to be like scientific information, something concrete, but it could be a viewer gains some sensory knowledge related to the ideas.  I think it was the right decision to put the projection across the ceiling.

John: Yes I think it was better on the ceiling.  If we had it on the screen behind it was too typical of a science talk.

Libby:  I think since the image was based upon the clouds, it made sense for people throughout your talk to be looking up and pondering your words.  Maybe it was somehow clichéd, but by thinking about big ideas such as time and the universe for people to gaze up and have a think about this seemed apt.

John: I was looking at the audience when I was giving that talk as well, because you want to see how it's going and it was interesting because people were really looking up during the talk and I think that was something we were worried about.  That they would just look at me and wouldn't look up.

Libby:  I think it helped that we were both looking up at certain points - we were guiding the audience.

Libby: Okay, so just one more question before we wrap up.  While we were rehearsing the project, Sabrina came to us and asked me to explain the details of the work before hand to the audience when we performed our piece, so the audience really knew exactly what was going on.  I kind of pushed back against doing this, because as an artist, I didn't want to be didactic.  I wanted to allow the audience to take the elements they wanted, to come up with their own interpretation and to interact with it in different ways.  What do you make of that?  In the end, I presented our piece just by discussing the title 'Time's Tattarrattat' so it introduced the project but not the details.  Were you happy with that degree of abstraction?

John: Well, I understand.  This is something else I learned from a project about art.  My opinion would have been very similar to Sabrina's the first time I talked to you etc.  The point is you know with these artistic things and shows in collaboration with a scientist, they shouldn't be just a way of trying to explain the scientists work.  It's not illustration.  For scientists, the automatic thing is to say 'how is this working', how do you find the nuts and bolts and it's a very reductionist point of view.

Libby:  Scientists want an equation.  They want to know how everything works to come up with the main idea.

John: Yes, it's a reductionist picture, where you want to know the inner working of the nuts and bolts rather than appreciating the whole, which is more in the spirit of art.  I think I agree with the artist there, let it be.  Let people think what they think and it should be good enough in the end that they get something from it.