It's very close to Charles Dickens' house, if you know that. Okay, so sorry for making you late. No problem. It's actually... I'm actually very happy that I'm one of the last speakers, because I can try to integrate a couple of things I learned from all of you the last couple of days in my own talk, so that might explain why some of it may sound a bit improvised. It's because it is, I mean it would have been a different talk had I been one of the first speakers. But I guess that's a nice thing about it. One of the... some of the overlaps I think that I have with a lot of the earlier presentations. First of all is this whole dilemma which is inherited vocabulary and borrowed forms, right, and how it shapes a lot of our debates that we've been having. And the other one is what to do with the philological attestations you may have in a sort of border version of a language, and how can they relate to reconstruction. That's another one. But I would say the main point that I want to talk today about is loanwords, what to do with them. And that's also because of my own discipline. I don't really work in a linguistic department or institution. I've always been the language guy in interdisciplinary teams, right? And then so loanwords are important because people more or less have an idea of what's going on and people looking at cultural context from a non-linguistic perspective can do something with them, right? So that's basically my PhD and a nutshell as well, which I did at the School of Archaeology in Oxford, and that was an interdisciplinary Indian Ocean project. So my task was to look at language context in pre-modern times between Southeast Asia and everybody else, which in most cases is just loanwords, right? You can't really tell much about grammatical influence if there's not too much data. So that's where I come from. I work at an institute which I can see as the little sister of SOAS. It's the Royal Mendelins Institute of Satisfaction Caribbean Studies. It shares with SOAS its rather strange labyrinth-like architecture, colonial past and also potentially interesting ways of looking at non-Western countries. And my own background in that is, say, Malay and Javanese, which are two Austronesian languages as you probably all know. And so I studied those. The reason I got interested in historical linguistics was because of that PhD in which I had to basically learn about the phonological histories of the languages involved. Of course, when you talk about loanwords, you're dealing with two possibly three phonological histories of languages that in many cases aren't really well described. There isn't one book of, say, the Malay phonological history, right? So you're dealing with a lot of indirect evidence as well, which makes it very nice to do. And it's basically one of the ways to gauge the time depth of lexical transmissions. Of course, the best way to see how old a word is in a certain language is philology. Specifically, if you have a dated inscription, which in Southeast Asia is often the case, you would have the shaka, the sort of Indic way of counting, and then you could tell exactly how old something is. If that year isn't in your inscription, you basically have to trust a philologist, and they can do paleographic dating and basically say how old something approximately is. So they have to trust philologists for that. And so basically along the way, I learned about all of these loanwords, and one of the things that struck me was that a lot of them were reconstructed to quite high-order levels of Orsonitian, say, subgrouping. So, of course, if you have attestations or reconstructions across different phylogenetic family trees and they're not things like onomatopoeia or kinship terms, that is something interesting. I mean, the chances of that aren't really high. And yet, when I ought to put it a bit, Kras came up with sort of debunked protoforms then people at first were a bit indifferent because in a lot of cases, the sound laws, the sound correspondences did what they expected, did what they were expected to look like. So you could argue that in terms of sound laws they were doing nothing unexpected, hence the reconstruction would be legitimate. But then, of course, the reconstruction would also not really tell that much in terms of the proto-language and all of the things you can do with a proto-language, all of these things like talking about a proto-society, that archaeologists really like and they take linguistic evidence for that. So that was a bit of the intersection of disciplines that I was balancing myself on. And I think it works like this. So basically today I'd like to raise a couple of methodological points, looking again at the Austronesian language family. And basically it isn't my intention to show how other people are wrong or anything. I think in a lot of cases, Austronesian linguists have been the only people right about a certain topic when everybody else was wrong. A textbook example of that would be the colonization of Maragastar, which for three centuries, I mean linguists have been known as an Austronesian language. And over the past 10 years maybe, archaeologists and geneticists have come to similar conclusions. So that would be a nice example. But I do think there are a couple of basically issues I want to point out. First of all, looking at old texts. I think that's very important. I think for some language families like Indo-European, it's very well established that you would do that.  In the Austronesian language family, I would say it's only old Japanese, which old Japanese basically means eighth century. So it's not really old when you compare it to some of the Indo-European languages, of course. But that would be the only thing and apart from that most of the languages that are being used for subgrouping are modern languages. So that is methodologically an important point to take into account when we talk about Austronesian languages. The other thing I would say is two important borderland regions. One is New Guinea as you can see here where the Papuan languages are spoken historically. And the other one here about is where historically there was a lot of language contact with also Asiatic languages. These are two things I will come back to. But for the time being, so I'll be looking at loanwords, language contact and basically the way that people from non purely linguistic backgrounds use these types of insights in, say, interdisciplinary projects. Like the one, by the way, that funded the conference. So that's how I know Nathan in the first place. I also want to make one point throughout the talk about the archipelagic nature of the Austronesian language family and how that may or may not shape the way we look at it. I mean, it's the most insular, I would say, language family. And I will argue along the way that that basically also shapes the way that the languages work in a very sort of, well, poorly understood form, at least by me. But first, let's have a look at the philology in sort of the broadest sense of the word and what are some of the issues that I come across in my work. So first of all, as we know from some of the Indo-European Afro-Asiatic languages, we have copper plates, religious scriptures, basically all of these, let's say, old texts, texts in the broadest sense of the word that give us a very good insight in the, say, not really what people would have spoken on the marketplace, but would have been a sort of literized version of the Daeglosic spectrum of those languages. And these exist for Southeast Asia as well, for the Austronesian languages. As I said, we have Old Japanese, which is pretty well done. There are some other languages as well, on which we have epigraphic data. But for some reason, well, for the reason of the absence of a dictionary, primarily, you don't see them back at all in Austronesian reconstructions. I'll talk about that a bit later. One of the other things that is really nice, I think, about, say, early dated texts in these Austronesian languages is that we can learn a lot about other language families as well, in particular Indo-Aryan, because of loanwords, and because the Indo-Aryan script, well, the Indic scripts to put it that way, often don't really give as much phonological information as you would have liked. For example, you wouldn't be able to tell how to short vowels. The Graspar would have been pronounced at a specific region in a specific time. Other things, you wouldn't know if there was interfocalic voicing in certain, say, Prakritz. And you get all of this information by looking at, for example, Old Japanese, which has borrowed a lot of vocabulary from these languages. And I suppose you could make a similar argument if you go west and look at Prakritz borrowings in Persian, for example, Middle Persian. You could get similar, say, additional puzzle pieces about the historical phonology.  So that would be a thing, or maybe something else, maybe a gap in the literature that at least I have come across. And then, of course, there is the earliest European descriptions, which in a lot of cases, a couple of centuries, 300 years, of a number of Austronesian languages, which, for most of them, will be the earliest extant descriptions in the first place. And there's nice things that could be done with those as well. One of my favorite examples is my colleague, Alexander Aghala, who has used, say, missionary, well, archives to make a complete reconstruction of the extinct Siraia language for most Austronesian languages that's spoken even north of Taiwan. Basically, using almost corpus linguistics and making a grammar of this language. So that's interesting as well. And I always wondered why couldn't something like that be done from a lay as well, with so many old word lists that basically tell you a very early stage of language development as well, which would be interesting for Austronesian linguistics, I would say. And my favorite example is the Chiang language, which is the oldest epigraphically, say, available Austronesian language spoken in Vietnam and Cambodia, what is now Vietnam and Cambodia, still spoken. It behaves in a very Montclair-like way, but it's evidently phylogenetically Austronesian, quite closely related to Malay as well. And that has been reconstructed as well. There is one book which is the reconstruction of Proto-Cham. The problem is that old epigraphic Cham isn't taken into account. So what you rather get is not necessarily Proto-Cham, but a type of early medieval, you could say, vulgar Cham, which in its phonological development is much more recent, seems to be much more recent than what you get in old texts. So that's important as well. Something that is called Proto might actually be relatively recent.  And my point is that, I mean, this could happen more in Austronesian historical linguistics. See if there's anything. Oh, the other thing that is really fun is Old Sundanese. It's one of the languages of Java. There are manuscripts being found quite old ones, even now in these sort of modern times when families don't really know what to do with the boxes they have in their attic. And basically they turn out to be of enormous linguistic value as well. It's just that nobody can read them anymore. So that's also something that could be quite high on the agenda of Austronesian historical linguistics but as far as I know isn't really at this point. So, you know, that sort of avenue of potential collaboration. Now to move on to the second point which is language contact. And these are all from my earlier work, by the way, but basically first to contextualize them a bit. Language contact is quite complicated when we talk about Austronesian languages because first of all we have these two areas of language mixing. One of them with what we call Papuan languages but they're actually quite distinct families as well. You just don't know the exact history yet. There's an area called Wallacea named after Alfred Russell Wallace, the zoologist who worked in Eastern Indonesia and discovered how the zoology was quite unique in that region. Well the languages are as well because they're all, I mean if you believe in the concept mixed languages so they take over each other's features. It doesn't really make sense anymore in that area to talk about Austronesian versus Papuan languages because people should go to each other's conferences and they often do. The other one which is I think a bit less thoroughly understood is the sort of Monkmer or Zonesian say mixed area, so Cham we talked about as well, but there's also languages in Sumatra, in Kalimantan that have distinct sort of also Asiatic features and even low words. One of my students, my first PhD student has just finished a book on Karimti, which is a Malayic language but it has this fascinating phenomenon, a phrasal alternation in which every word has a different ending whether or not it's sort of contextualized fracially or standing as an independent form. And the sound those use for that aren't Austronesian at all. It much more resembles something like Khmer or the Monkmer language is spoken now presently on the mainland. So these are the language context of a sort of more of a deeper time depth. But I've been looking at the Indian or Indic language context as well making a list of words that I thought weren't really sort of real protoforms to begin with or there may have been real protoforms if you expect a sound loss, you expect a sound loss, but they were borrowed. It's my point. From different places, from the Arian languages, but also from Dobilian languages in which Tamil seems to have been quite important. And also, I mean Hindi isn't really the right word because Hindi itself wasn't really used as a term at the time of context, but a sort of medieval prakrit I would say. So those are some of the basically things that I came across and what was interesting is that a lot of them were reconstructed to proto-wesse Malaya Polynesian which, depending on who you believe is a bit of a tricky sound family to begin with it happens to be the case that proto-Malaya Polynesian involves all of the languages historically in contact with a Indian Ocean world to begin with. Not the Pacific, not Taiwan but basically what is now Indonesia and the Philippines precisely the area where you would have expected loan words from Indian Ocean languages in. So that's interesting as well because the next question then would become how legitimate is the sub-family if it's full of things that can be demonstrated to be loan words. I don't have the answer to that one as well but it is something to take into account especially if for example they do unexpected things like the Malay R corresponding to an L in Philippine languages which would have been a G, a good if it were inherited these kind of things. So there's a couple of red flags there as well and thus far I haven't been publicly executed in the process was published in Oceanic Linguistics. I think that's fine also because you can revert the logic and say I'm going to use Austronesian linguistics to debunk some of the fake loan words scenarios that are being promulgated in the wider literature not necessarily by linguists but by social media experts it seems to be that a lot of people want things that are also niche to be from other parts of the world and then historical linguistics and linguistic reconstruction can actually be a corrective mechanism there as well to say for example these words aren't really from Sanskrit, from Tamil or from Arabic but they can be reconstructed quite regularly and there's a bit of a problem with the linguists who are obviously interested in language I get a lot of questions through email as well about where does a word really come from so there is some sort of societal interest in that as well but there are a lot of people who really want a lot of western Austronesian words to come from India which reminded me of the popular 1990s character from the BBC show Goodness Gracious Me you should watch it, it's really funny but even in a European context there will be this stereotypical Greek uncle everything comes from Greek so it's not really unique or anything okay then which is I suppose the last point of some of the issues that I come across and this has been mentioned yesterday as well during the keynotes is the problem of doublets in Austronesian languages in general but specifically a Western Malaya Polynesian these are just a couple that I found in the paper by Robert Bluss but there are hundreds and hundreds more I think the Austronesian language family may be one of the most, I mean has the highest fecundity of the reconstruction of potential doublets, you can see there's different types as well, some actually share a morphological unit or a morphemic unit others are basically throughout all of the languages that have been reconstructed you find these two forms coexisting now what does that mean does it say something about the language family, does it say something about the people doing reconstructions probably a bit of both, remember we're talking about a lot of violence that won't really isolate this was an archipelago archipelago sorry, where people were coming back and forth where people were maritime in their orientation so there is a bit of a sort of continuous tradition of going back and forth if you remember your paradigmatic Austronesian family tree branches off in like eight different things and then one of these sub-branches goes again in eight and then one in eight as well suggests that there was a multi or mono directional movement but of course people were going all over the place and secondary borrowing and these kinds of things seems to be quite the norm one of the things where I think protoforms could really give a wrong impression is one of the case studies I got an email by an anthropologist looking into what's a taboo in Austronesian basically languages and what you find going through the Austronesian comparative dictionary is that it reconstructs really, really high up but the only legitimate reconstruction here is the oceanic one which makes it a Pacific sort of thing whereas the other attestations and these are basically varieties of the same language are only attested in one tiny corner of Indonesia and they also mean something different so that is a bit of a problem for the sort of non-linguists who want to use Austronesian reconstructed data for their own work because some reconstructions maybe shouldn't be there or shouldn't be made but of course who decides these things, right? There's no high supreme court of historical linguistics or anything like that so it's also one of the things I come across I think I'm slowly moving to a number of concluding remarks which is first of all the earlier pointed it might be a bit of a problem for Austronesian linguistics specifically not necessarily the Pacific or Taiwan but specifically say the Indonesian archipelago which people say is a cradle of globalization and people are moving back and forth for the past three millennia that there seems to be little collaboration yet between say the historical linguists working on the region philologists that is one of the points that I think could be could get some attention in the future and so yeah it kind of makes me a bit jealous if I look at some of the Indo-European stuff in which there seems to be, I mean it might be that the grass is always greener but there seems to be more attention for people looking at philologically attested old languages versus what we can do in terms of reconstruction maybe the same with the Semitic branch and the other thing is I think the really cool computational stuff that happens for example for Sino-Tibetan is not really the norm either yet in Austronesian linguistics although there are people doing it now so that's nice then again the good thing about the Austronesian languages is that there is of course a lot of data and that a lot of people are working on it some regions are pretty well done others such as East in Indonesia, I mean very very little actually makes it even to the Austronesian comparative dictionary so that is a bit of a problem now in terms of knowing where the field is moving and what reconstructions are there and basically that is a bit data deprived now at this moment I would say so finally and this is where my earlier research sort of comes in, is how these things then resonate with other people who have an interest in old languages to put it that way but aren't historical linguists or the archaeologists that I work with historians, I mean archaeology is nice because these people are interested in all sorts of data, zoology genetics language, plant, science all of it historians I would say less so even though they could learn a lot from people like all of you for example in terms of what a region looks like prior to the appearance of the earliest documents and descriptions that's not really happening I suppose too much in Southeast Asia, some do it but it's exceptional so I think this might end up being a bit of a plea for closer collaboration as well between all of these disparate fields maybe over cocktails and pizza I'm not sure but one of the things I was interested as well and maybe that could be talked about during Q&A is also how some of this resonates to the fields that you're working on and how it's completely different or similar what are some of the problems maybe also what are some of the solutions about all of this so I guess that's it thanks for not sure if I made it in the right time slot or thank you


Hey, what's up coach? This is Nick Aldera with make money coaching sports and today. I'm going to talk about Three keys to your basketball training business. Have you haven't done so yet? Please subscribe to the channel smash that like button and also Any questions that you have feel free to ask them in the comments if you're looking to connect Text the word grow to<PHONE_NUMBER> So what are three keys to your basketball training business? Okay number one Is attention, right? So and what I've put into that category is you know marketing your your program or your product You know, how are people seeing? Your training, how are they seeing you as a basketball teacher? What are you putting out there? How are you gaining attention? So that has to do with your what you're putting out so parents can see right whether it's Facebook Instagram Tiktok YouTube, whatever Can I so they did a glimpse of what it how of what it looks like and how often are you putting it out so they can really see What it's like and does it does it tempt them to contact you and be like hey, this looks this looks pretty cool, right? So do you show the kids being able to do? Specific skills. Do you show your ability to communicate? Right? So there's different facets of attention So you got to market yourself the best marketer is usually who wins now you can have a great program But if nobody knows you if you can't garner any attention, it doesn't matter. So you could run paid ads, right? That's an option now. I personally don't for my business But it's not it's not that it's wrong You could definitely do that or you could use Facebook and tag the parents of kids who are in your videos and Just you make a video every time you do training and show them doing great things and show You know who the player the day is tell them who's the player the month and who's been doing their training homework and things like that Right. So number one is attention. Okay, number two is the systems you have in place So what is your onboarding system where people they contact you and then what happens?  Or are you in control of it? So for me personally one thing that I do is I have an application system where parents have to talk to me first and We have an interaction on zoom now. Do you have to do that? No But it's always better to have a face-to-face interaction and you ask them questions to see if their athletes a good fit for your Program, okay, so that is one way to onboard clients But I suggest having a certain system in place now What else falls into system systems falls into how do people pay for for training? Is it all over the place? Do you accept cash? Do you accept check? Do you accept Venmo or do you have a system in place where clients are automatically charged on a certain day? Or whether it's a month monthly three months six months twelve months And it automatically renews so you don't have to go in there and resell everything So system that type of system is is falls into that category as well, okay? And number three is you're obviously your your product, right? You're your ability to coach, you know, are you constantly learning and actually helping kids improve their skills? because Even if you're if you're a good marketer It's going to help you But then once people get in if they if they see that you don't know what you're doing or you're not a high enough level They're probably gonna leave Okay, so you don't want you don't want that being the reason why people leave now If people have other things come up like they plan a bunch of teams and they leave your program because of that because it's Scheduling that's different than they realize that you don't know as much as they thought that you knew so Who you are as a coach needs to be worked on and you need to obviously be really really good But you still need to garner the attention You still need to have the systems in place, right? And then of course that we're talking about right now. You got to be able to coach communicate and know the game Okay, if you are looking for extra help on how to grow your business text the word grow to<PHONE_NUMBER> And it is your text see me coach Nick I will directly text you back and set up the time so so we can talk Alright, I'll see you next video


Has the conference started yet? This morning. Oh, yeah, I didn't consider getting up much earlier Yeah, it's already kind of early you are online Can can the audience hear us? Yes. Yes now we are That's why we are maintaining dignified silence Maybe you can mention we're just letting people in Okay, yes Okay, welcome everybody. I think We'll start in a couple of minutes. We are just waiting for all the participants to join us. So just Bear with us for a couple of minutes. Yeah, I think maybe maybe we can start now So we are very pleased to welcome professor Frank. We'll check here today This colloquium is on time crystals past present and future and it's related to the To the conference on time crystals, which is taking place online at ICTP this week Co-organized by my colleague here, Professor Rosario Fazio and Professor Sasha Kristoff from Jagiellonian University in Krakow And it's co-sponsored by the Trieste Institute for the theory of quantum technologies So I think I'm sure all of you here are familiar with Frank Wilczek he is a Co-recipient of the Nobel Prize in physics in 2004 along with David Gross and David Pulitzer for the discovery of asymptotic freedom in the theory of strong reactions It's one of the great landmarks in modern theoretical physics And then of course Frank is very good at naming things He has many interesting names to his credit including axioms and anions and now time crystals but of course in all these behind these names he actually pioneered completely new fields for example axioms is now very you know very important potential candidate for dark matter in cosmology Aeneons is a big field in condensed matter physics and now today we are going to hear about time crystals. So he has this impressive breadth of contributions to physics. I can also say that he is an inspiring teacher When I was a student at Princeton, he was a professor at the Institute for Advanced Study I didn't have the opportunity to take any courses from him or work with him. I was working on string theory but I recall that Frank used to have this very nice post-dinner evening meetings at his home Just to discuss about whatever was occupying his mind at the time. I remember at that time it was about various phase or something like that and it was it was held at this famous address in Princeton is 112 Mercer Street which is the old house of Einstein's It was quite an experience as a graduate student to go and you know listen to the known interesting just to bounce off ideas So we are very happy to have Frank with us today And I will leave the introduction about his colloquium to Professor Thank you, Adish Just very good remarks. I mean, of course we are all thrilled to hear Professor Wilczek This colloquium is about time crystals As Adish said is connected to a also connected to a conference is Running in these days from today till wednesday and organized by this of sucking myself here at ICTP on a topic which was initiated by Professor Wilczek almost 10 years ago a couple of papers that really Put the seed on this and Let people think about this new state of matter, but But during this Times a lot of things came out, especially very interesting Experiments and now it's not only just a theoretical question, but It's confirmed state of matter and I will just pass The floor to Christoph soccer before Stuffing The colloquium Christoph Thank you. I would like to say that I learned about the works on time crystals by Frank Wilczek and our chapter in 2012 shortly before they were published because my colleague was invited to write a viewpoint on time crystals To American physical society and it was a unique experience when reading articles you realize that uh That your eyes are opening to a whole new direction of research And of course, we know that in order to conduct scientific research, we need seeds And We know that Frank Wilczek is a person who's constantly providing the seeds. So that's all thank you Well, okay, I'm on I guess So thank you very much. Thank you for these very kind introductions and my topic today And it's nice to be joining you even if virtually I'd love to be in sunny Italy. I'm here and uh, well sunny but but cold Concord, Massachusetts, and it's Not not the same Today, I'm going to be talking about time crystals as advertised and this is a subject that Got it A distinct identity I would say About 10 years ago as has been mentioned but has roots That go back much further and I'll talk a bit about the past I'll talk about what's Just a couple of highlights of what's happening Now you can hear much more about that in the conference And I'll I'll present some ideas about where I think The subject might develop in the future So, uh, the Tao of Tao Time translation symmetry needs a name that's shorter than time translation symmetry So I call it Tao And that enables this little joke that We can talk about the general state the general position of time translation symmetry in physics And symmetry is a big theme in modern physics, of course And time translation symmetry Is a profound widely occurring symmetry If you think about it, it's the symmetry that says that there are Permanent physical laws Uh, it's also by Nurtis theorem connected to the conservation of energy And uh, so it's it's a very very Profound feature of the natural world that Another Theme of modern physics that's been extremely fertile is spontaneous symmetry breaking though, uh We know many systems where the equations have more symmetry than the stable solutions and Under A wide variety of circumstances that mismatch between the symmetry of the equations and the symmetry of a given solution Which might be a material Has a whole series of consequences that are very rich having to do with the existence of phase transitions the existence of soft modes And others which we'll come to discuss so, uh We have these two big themes What could be more natural than to join them? however Explicit focus on the issue of spontaneous tau breaking Or what come to be known as time crystals is a recent development And the fruitfulness of that union is only becoming widely appreciated Recently And why did that happen? Why did it take so long? Well, uh spontaneous tau breaking brings in subtleties it's not just another symmetry that it's not a routine generalization of Spontaneous symmetry breaking to take it into to apply it to tau The analytic mechanics of time crystals looks problematic So if you try to write a Hamiltonian in particular For a time crystal And look at the Hamiltonian equations. I'll actually write this down below If you look at the Hamiltonian equations They are equations that are what's called gradient Descent gradient equations that is the time derivatives of p and q Are related to the gradient of the Hamiltonian in phase space and uh At the minimum you would expect the gradient to zero to be zero and so nothing happens To get around that you need to have something strange And uh At least spiritually and vaguely related to that energetic criteria for many body spontaneous symmetry breaking Uh are not straightforward to apply to tau breaking because tau breaking through its Connection to the conservation of energy means that energy is not conserved And so saying you're trying to minimize the energy is uh is a little questionable So those are formal problems. I think much more alarming when you start to think about Spontaneous tau breaking is that it seems to be in great tension with Uh conventional wisdoms that are very Seem very uh Wise very well established Uh one is that in a quantum mechanical ground state nothing happens The time evolution of a quantum mechanical Ground state is or any eigen state is just that it it gets multiplied by a time dependent phase And of course if the wave function is multiplied by a phase that really has no physical Significance Uh also, uh There's a strong intuition that nothing happens in equilibrium states even if we're moving we want to move outside the framework of Zero temperature to non-zero temperature There's the strong intuition that nothing can happen in thermal equilibrium states that's that's the statement that there's no perpetual motion Nevertheless nevertheless There's been a hunt for time crystals Uh over the last few years that's actually been very exciting and very fruitful Uh, this this was uh a so-called advent Sir television series in uh in sweden called the hunt for time crystals had nothing really very Tenuous connection to the time crystals. We know and love in physics But was very popular and a lot of fun and you can see Uh that it's the name is very evocative for many people Okay, so so now let me uh launch into the body of the colloquium talking about uh time time crystals past and I'm going to focus on Uh Josephson effects because well, there's among the most beautiful effects in physics The josephson effect itself goes back to the early sixties but Generalizations are very widespread and and and large classes of modern time crystals At least there is there a spirit a an family resemblance to josephson effects And and as you'll see it's very instructive to work out the formal description of the josephson effects in a way that addresses Uh the fundamental objections if you like to to time crystals The counterintuitive aspects we just mentioned So, uh, let me remind you what the josephson effect is uh In cartoon form. We have the junction between two superconductors with what's called a weak link So that whereas in a bulk superconductor, there's a well-defined phase When you have a weak link the phase can be different on the superconducting Phase can be different on the two sides And what's found experimentally is that when you apply a constant voltage across such a junction You get not a constant current but An oscillating current an ac current So this is a search. This is a situation in which you have a time independent Set of equations a time independent physical setup that gives a time dependent response Uh We can describe this very compactly and very elegantly Uh with a Lagrangian that captures the relevant physics so, uh, there's a phase number Conjugacy between the number uh the at n actually is the difference in the number of cooper pairs on the two sides and The difference in phases delta is conjugate to that There's a coupling term which says that there's an energetic cost To having but a finite energetic cost to having a difference in phase across across the junction between the two superconductors and then finally there's a Uh an energetic cost a simple voltage if you if uh because there's a voltage if you move A pair from one side to the other and that's it Okay, so those are the relevant effects And then if those are the relevant, uh physical Circumstances that are sort of necessary and sufficient to understand the josephson effect If we vary this Lagrangian with respect to delta We learn that we have a current which is j zero sine delta And if we vary with respect to n We learn that the time derivative of delta is two e v over h bar And so putting those together we see that we have a time dependent current in response to a Time independent voltage so in this Lagrangian nothing depends on time, but all the solutions do So tau you can see that time translation symmetry is broken here because if you Change t by a constant the argument of the sign changes And we also have a soft mode a kind of Nambu goldstone mode Namely this phase delta zero Is something that's kind of the residual of the time translation the original time translation symmetry and as Uh, if you made a time translation, you would in effect change delta zero and that so Uh, that's why there are solutions for every value of delta zero Delta zero they're related to each other by the broken symmetry of time translation Instead so when the symmetry is broken you get a whole family of solutions by starting with any one of them And there's a soft mode that interpolates in between the solutions Uh, it's instructive because of the difficulties that with canonical form with Hamiltonians that I mentioned to see how that's avoided in this circumstance And it's instructive also because if we want to quantize the josephson junction if we're dealing with Cases in which the the phase Is not a completely well defined if we're dealing with small superconductors where the phase Significantly fluctuates we should quantize the whole thing Uh, and then we need a Hamiltonian So to get a Hamiltonian. Well, it's straightforward given the Lagrangian And we identify the canonical momentum by varying with respect to delta dot using delta as the dynamical variable And then the Hamiltonian is this extremely simple Hamiltonian. That's linear in the canonical momentum and Sure enough all solutions are oscillatory It's the same equations basically and you get the same solutions Uh If you write down the schrodinger equation for this, uh, you get a first order partial differential equation because the the pi sub delta turns into a derivative with respect to delta A partial derivative with respect to delta and first order differential equations can be solved completely There's no no necessity for Fancy analysis going into energy eigenvalues. In fact, that's a very awkward way to analyze the system You can just write down the solution for any given set of initial values and see see how it evolves and Use the method of characteristics to see that the classical solutions underpin the quantum mechanical behavior This in fact beautifully embodies a framework that's much more general that I'll discuss at the end Because I think this is a case where the past Coins to the future when you think about it Correctly or think about it and From the right from a fruitful direction Just a quick question. So it's the Hamiltonian is not positive definitive. No. Well, yes, we're coming to that So so what happened to that big problem that I mentioned that if you take this gradient flow and minimize It seems to imply that q dot and p dot are zero Because when you go to the minimum the gradient will be zero And the answer is there's no minimum This this Hamiltonian is Linear in the momentum so the momentum can can fall as low as you want And there's no minimum to the energy and so what so what As long as it's a closed system, we don't have to worry about it's catastrophically If it doesn't matter that it doesn't have a ground state Whatever whatever state it's in it evolves in a perfectly nonsingular way so Okay, so let me move on from there to discuss a little bit about time crystals present and again you can Learn much more about what's going on in this vibrant subject at at the conference And it looks like a very exciting lineup and certainly a lot is going on But I'll just mention a couple of highlights So some of the most interesting time crystals involved driven systems with What's called sub harmonic response? so the drive Hamiltonian Does not have complete time translation symmetry, but has time translation symmetry under a discreet translation Discrete version of time translation symmetry So if you like the drive itself is a kind of crystal but But the the system that we'd like to call the time crystal in this context Has less time translation symmetry than the equations that govern it Now sub harmonic response of driven systems is a very well studied phenomena with enormous literature Going back at least to faraday Faraday did experiments in which he looked at the surface of A bowl of mercury that he shook up and down in the presence of a magnetic field and found a sub harmonic response of of its hydrodynamic modes And there are many many other circumstances in fluid mechanics and geophysics and so forth where You find sub harmonic response but What's new and different Is that we can only really claim to have a distinct state of matter here When there is a clean separation between the system and the drive You have to have part of it that's you want to call the time crystal that's broken the symmetry and another part That's the drive But if you can't make a clean separation between them, it's just a system that has less less Time translation symmetry than then then you thought and then it's not it's not Isn't there's nothing spontaneous about it. It's just a system that that is oscillating at a certain rate So in order to identify the system as separate from the drive We and and to get the consequences that we normally associate with spontaneous symmetry breaking We need to demand that our system ceases to exchange energy and entropy with the drive Then we can say that there's a system here and a drive there and they're different things And it turns out that that that separation is enough to In the presence of spontaneous symmetry breaking fully realize the combination of rigidity and softness that characterizes spontaneous symmetry breaking and makes it a powerful tool in Different parts of modern physics By rigidity, I mean things like that we can have sharp phase transitions into and out of The symmetry broken states as we vary parameters. So we get sudden changes in in the symmetry Uh And also that the faith the the states that we get are robust under local perturbations. They have the kind of long range order here in time that Is maintained even if we allow small regular irregularities in um In the exact nature of the drive or Or other yeah, and in or uh in in the external world On the other hand, we have softness Uh because there if you make Make transformations that uh restore the symmetry on a large scale gradually Uh So ideally non-locally you could just change the whole material into it's as we saw in the josephson effect change Change the the overall phase all at once then that costs no energy It gives you takes you from a solution to another solution And it's always perfectly fine if you change it gradually that will cost little energy And the system will be sensitive to perturbations of that kind So this is the philosophy that gives named google stone modes In particle physics and condensed matter and and when you have Gauge interactions long range interactions on top of this it also gives you the higgs phenomenon and so forth so we have a combination of robustness under a wide range of perturbations and sharp phase transitions, but on the other hand sensitivity to certain kinds of Long-range global perturbations now Again all all this these wonders occur only if you have a clean separation between system and drive And it was not entirely clear prior to 2017 that this kind of system drive separation could happen it's Not true of the systems that faraday studied and is not true of many of the other systems that have been studied In the intervening years. It's not even necessarily true clear of the josephson junctions Without taking special precautions If you have a voltage that means you have a battery somewhere and the battery can run down so You need you need to You need to make sure that it's really a time independent system and whatever whatever is causing the Voltage to stay constant is really not affecting the dynamics of the junction Okay, in any case It was not entirely clear prior to 2017 that this kind of system drive separation could happen And then came a dramatic issue of nature magazine Which made me really happy Which you see here where time crystals are on the cover uh, I should Tell you that this is not a picture of a time crystal at all not even remotely Uh, it's an it's an artist's inspiration somehow of a mystical thing which is some kind of combination of time and crystals and That has very little to do with the actual experiments, but inside the inside this issue. There were two wonderful experiments that showed that you could have these kinds of so-called driven systems so-called floquet time crystals In which there was a clean separation between the drive and the system of interest and uh, and you got some of the Characteristic signatures of spontaneous symmetry breaking. So there were two discovery papers There was a so-called news and views which was a scientific Appreciation by an expert. There was there were also and then there was also a very large More popular description of this so it was an issue that was just chock full of time crystallology and The the basic recipe is deceptively simple For making these things one uses a two-step stroboscopic drive In one step we apply what's called the many-body localization Hamiltonian that Uh Whose eigenstates are locally ordered with respect to the z direction of spin. So Roughly speaking it's kind of uh, A disordered ferromagnet where you have Ferromagnetism of an unusual nature where There are conserved pieces In different places. It's kind of ferromagnet that does not have normal thermodynamic properties It's very hard to transfer heat from one place to another And in the second step one flips all those spins So the special feature of many-body localization, which is very which is important to getting this separation Is that it can reach a State of equilibrium where it does not keep heating up as you apply the drive Uh, it it settles into a sort of non-ergodic state where That it no longer can absorb heat it reaches a kind of equilibrium. That's non-trivial Where it no longer can absorb heat from from the drive And in the second step, so it's ordered and as ordering with respect to Preferred direction the z direction and in the second step one uses nuclear magnetic resonance to flip all the spins so There's a two step drive and one step we establish the state and the other one in the other step we flip all the spins and Because the spins are flipped The result of this cycle is not the same as as uh, as what you started with you have A flip and you change the periodicity of the the periodicity of the response is twice as large as the periodicity of the The period is twice as large. I guess the periodicity is quicker less than uh, if uh, then the Then the drive so, uh for physically realizable states Then the ones that have these ordered arrangements of spins Time translation under one cycle period is broken on the other hand time translation symmetry through two cycle periods remains valid We have what's called period doubling Uh Choi at all even in this pioneering experiments reported also that we're using a different protocol They'd have period tripling in the intervening years many many more elaborate patterns of Time translation symmetry breaking have been observed and So here is the ax is a numerical simulation and then The actual data looks something like that and so you have the A non-zero expectation value of the spin in the z direction which flips Half as fast as the drive Is is as the drives period And this behavior Can be is robust under changes in the Flipping protocol so that it's not precisely flipping by uh by pie Nevertheless So it doesn't directly flip up to down.  Nevertheless, the time crystal is robust against that that Uh for a range and also the amount of coupling Can be varied and you see phase transitions between the time crystal with this Doubling of the behavior of the order parameter And more conventional thermal states or trivial response where it follows the drive Directly and there are sharp phase transitions that Distinguish these as a function of the parameters Yeah, I should uh Yeah, I should have mentioned let me go back to it for a moment A little bit more about the two experiments Uh one of them Involved uh a handful. I think I was 11 or 12 Different atoms that whose interactions you could control very precisely using Lasers And so you had a Hamiltonian which was suggested by theorists and was the basis of those numerical simulations and and basically the experiment was just a simulator which Realized those Hamiltonians by clever manipulations of the atoms using Lasers to put them into levels where they could exchange energy or not and so forth Uh, the other was a more naturalistic experiment in what in using what are called nv centers Uh nitrogen vacancy centers in diamond and in this case they were it's a A more natural system where you doped things in uh to a diamond dope nitrogen in and uh that presumed that Those vacancies have effectively dangling spins which interact with each other And it turns out that those For reasons that are not completely understood because this was not Simulating a known Hamiltonian, but a natural system that was built for other reasons That that this behaved as a time crystal too So as I was mentioning since then many other time crystals have been explored Uh, it's important to note that different investigators have interpreted the concept more or less strictly So When we say that it's that we that we want to insulate from the external world We don't want to we have to when we have a state of matter. This is a very general Consideration when we have a state of matter We uh that exists under certain circumstances for a long period of time and how you strictly define the circumstances And how long the period of time you wait is is very much Uh Up to you and and and people can define things in different ways Uh, otherwise the only stable state of matter would be a black hole Because eventually things will the protons will decay and your your system will decay will Spontaneously collapse into a black hole. You have to uh, you have to use things that are relative to human human times or laboratory timescales and And a certain range of perturbations that you allow Or or shield again or protect against Okay So so people have used different definitions of time crystals if you use a very strict definition Of what spontaneous symmetry breaking means then you get more consequences But there are fewer examples if you use a looser definition Then you have more examples, but the the uh These the strong consequences of spontaneous symmetry breaking get diluted Okay, so uh here i'll just so again if you want to learn more about this thriving subject There's a conference going on and it's all around you There's tremendous vibrancy on the internet You can you can tap into Here i'll just share one of the latest which is very exciting and Uh Brings in spatial dynamics This is uh just appeared from Groups in and located in germany and poland Uh where they they have a system uh with a Magnons that condense into a kind of spin wave That evolves with time That uh can be considered as a Uh A spacetime crystal so it evolves not only in space but also in time and I should be able to show the movie Do this right? Yeah, there we go So they actually have A picture where you can see And this is very exciting as we'll see because when you have Uh time crystals that are that also have spatial structure a whole new set of questions arise And opportunities Okay, let me see Good, so let me then say a few words about the the future Uh, and this is going to be a very biased View of the future. It's basically things that I've been interested in recently and I'm developing but they're There are actually no proper papers on it yet and uh, so Uh caviar at empty or bio beware But I think these are very promising ideas and directions One of them. I've already alluded to the idea of sensitive modes. So what are time crystals good for? Their rigidity Their insensitivity to perturbations Uh could be used I think plausibly in the future to make better clocks better atomic clocks better along along If the improvements could be made along several axes one is absolute accuracy one is making things that are smaller and tougher uh As you know atomic clocks are a big field that uh power the gps system among others And making ones that are smaller and portable would be a very important thing As well as making things that are more accurate So, uh, it's very intuitively plausible that by Hooking together many atoms You can make things that are more robust than and Still have the advantages of single atoms But another direction that that would uh exploit the rigidity having to do with Spontaneous symmetry rigging, but there's also the question of uh, it's rigid rigid against some kinds of perturbations But unusually soft against other perturbations the ones that tend the more global trans transformations that tend to restore the symmetry so, uh We know how powerful that can be in the context of super fluidity and superconductivity Where you can derive all the main phenomena Starting with the notion of spontaneous symmetry rigging the main macroscopic phenomenon The essence of the matter is exploration of the vacuum manifold through a long wavelength almost non-local perturbations Now, uh To make Though uh, conventional namboo goldstone modes, uh, you need To be able to make perturbations that are very gradual and it would seem that if you have, uh Discrete symmetries being broken as in the, uh Floquetime crystals, uh, that This this this couldn't be applied. However, there's another way to get soft modes Which let me exemplify in the icing ferromagnet uh And basically the ideas instead of moving individual spins gradually you move the boundary between spin Spin up and spin down Gradually by small perturbations So, uh, here's a concrete example So we take an icing ferromagnet and then So it's symmetric between spin up and spin down. It chooses one of those directions Impose a global field a global b field to make the chosen state Energetically unfavorable so your system chooses a direction And then you apply apply a little field to say that you chose wrong That's the wrong direction and then it's then it's metastable It would like to point in the other direction But it has a hard time doing that because, uh Because you have to flip all the spins and the interactions are local and that's Not easy to for them to all cooperate and flip at the same time There's a big barrier to it. In fact an infinite barrier in the infinite volume limit Uh, but what you can do is give it some help by, uh Flipping some finite region of spins And then the question is does this region grow or not? And the energetic differences between growing and not are very small and that's connected to the fact that you can Make continuous changes in the shape Or more or less continuous changes in the area And see that there is a very small energetic cost to, uh, to those kinds of small changes so, uh Well, I won't I won't attempt to to Because of the time limitations. I won't go into great detail great detail on this but, uh You just take that kind of issue in space And turn it into time where we have a kind of icing behavior More like an icing ferro magnet in time where the flips the things were flipping up and down as you saw and, uh what you can do is make A magnetic field which favors the other directions of the spins an oscillating magnet and, uh, and then a finite region where The system does what it what it really wants to do energetically and then see if it grows and so you can reproduce all that uh, it's kind of, um hyper cooling, uh super cooling and, uh Nucleation in the context of time crystals, I believe and because the energetics near this, uh Transition are controlled by the fact that you're trying to restore a symmetry We can make universal statements about The relevant modes Another possibility That arises when you have spontaneous imagery breaking is the possibility of topology When you have defects and if you have Time crystals now that are also have spatial structure Uh You or even if they don't didn't have spatial structure, but but it's easier to visualize if you have spatial structure You can imagine introducing defects Uh, you can imagine for instance. Okay, so our our pump is going through a certain number of cycles In general, but you might in a small region of space have the pump doing one extra cycle Or one less cycle that introduces a defect Into the into the time Uh crystal how does it respond does it respond in a way that is stable as it goes forwards in time? What are these kinds of topological quasi particles that Settle out or are they reproducible? Very little is known about this, but it seems like a very interesting kind of question How can we make it if they are reproducible? Can we make a gas of them? What are their properties? Okay, so that's that's one idea for the future another one that I I'd like to share is also Quite nice. I think so this was a beautiful picture that caught my eye. This is supposed to be a picture of a proton Uh But wait a minute. Okay, so proton is supposed to be made of three quarks. We understand that but but then What what is this beautiful picture mean where you see things happening inside the proton? what And we have some intuition that there are quantum fluctuations going on and and things are moving around but On the other hand if we go back to our textbook of quantum mechanics or just look at a proton nothing is happening right, so So, uh What are these pictures mean? We think they mean something and more more more over in chemistry chemists are very fond of drawing pictures and molecules with balls and sticks and things moving around and resonant resonant resonances Uh resonating valence bonds that percolate around what what does that mean in the context of ground states or Things that have had in some sense aren't changing in time Okay, so the intuition I think behind this movie and many related pictures Is that the quantum state can be described and it's advantageous to describe it as a superposition of quasi-orthogonal states that in some sense evolve classically So we take not the usual analysis of a wave function in terms of energy eigen states where nothing happens But take the wave function as decomposed into a state into a frame that itself evolves in time so states that are that have a kind of uh coherence to them a classical behavior that are quasi-orthogonal that we can understand And when we're making these pictures we're making pictures of a typical such state that's That's the now can this intuition be made precise and may be useful And I of course, I wouldn't be talking about this if I didn't think the answer was yes Uh, first, let's think about it in a slightly more formal way Uh, what we'd like to say is that we describe the path integral. Uh, that's uh applying to our quantum system, uh, and We want to we want to decompose it into a collection of dominant paths That are not necessarily time independent And but when but one changes into the other as a function in other words, we have kind of time crystals that That are the a better way to analyze it and this is very much the case in the josephson effect and the josephson effect That the uh as if you quantize that the energy eigenstates are of very little interest what that what and the the the thing or or I shouldn't say that they're of interest, but they're not the natural way to analyze it The natural way to analyze it is in terms of the time dependent solutions that we know as the josephson effect that people see in laboratories And and and and perturb around those To build in the quantum fluctuations so Now there's a Beautiful, but I think underappreciated way uh due to kutman and von neumann of recasting classical mechanics into the same Framework, I'm sorry. I duplicated the work The the the word form and framework this should be you should choose either form or framework But in any case Framework where as we have come to know and love in quantum theory with wave functions Probabilities strobing their equations and so forth. Let me show you how that works. In fact, I'll show you a generalization of the kutman von neumann trick that Takes even dissipate of quantum mechanics into the framework of a dissipative classical mechanics into The framework of quantum mechanics so Just consider a dynamical system a classical system that that's you Have in this form. So hamiltonian form is fine, but it's not necessary hamiltonians are Hamiltonian formulas and gives you this but you could you have other things that uh, for instance, I studied in chaos theory or Vander paul oscillator and other things that that Are analyzed this or fall into this category, but aren't hamiltonian and what you do is Make these quantum mechanical equations of motion of a system Uh, so you elevate the y's to operators in hilbert space that commute with each other You can get however this equation of motion as a quantum mechanical equations of motion By introducing conjugate variables to the y's so effectively momenta and then uh using this hamiltonian Or actually you can also add to this hamiltonian any function of y because That will commute with y's the y's and give you the same equations of motion But this one's good enough to get those equations of motion And so we've embedded our classical system into a Full quantum mechanical system as wave functions shorting your equation, uh, and so forth So at the price of expanding the formalism and using a rather unusual hamiltonian that's linear in the momenta When even these particular momenta Exactly what we found in the in their joseph's in effect We've embedded our classical dynamical system into a conventional quantum system the special feature of wave functions in y space is that they don't spread in fact they Evolve according to the classical evolution. That's how we arranged it. So they can be The things that That beautiful picture was a picture of it's a picture of a classical approximation Or a classical model of a quantum mechanical system Promoted in but we can now promote it into a full quantum model and embed it as the start of a well-defined approximation scheme so in this way time crystals become The foundation of everything as Of describing an alternative way of describing Quantum mechanical systems that can can be advantageous. I think in a wide variety of circumstances okay, so With that I will just Conclude I've given you a very personal sampling of a few of the highlights of time crystallology I hope I've at least conveyed the sense that It's an exciting subject and the hunt continues in laboratories computers and minds. Thank you So thank you very much. Thank you for a beautiful talk. So I think I don't know probably it's easier to start from the panel if you have question. Otherwise, there are several questions that are Going up. Should I should I should I I can Yeah, no, no, I can I can read the The question, okay, I'll leave up. I'll leave this slide up anyone because I think it's a very charming What? Okay So there is the first question by James singled by so He would like to Some clarification would like to understand better why Justice and juncture is not the perfect example of a time please. So let me see understood this way I think it is a very good example Actually, okay, but some people some people claim that it's not truly an equilibrium system because you have a voltage Uh And to be sure if you plug into a conventional circuit with a battery the battery runs down and there's dissipation and there's resistance somewhere Uh, but if you take it on its own as an ideal Lagrangian, there's no question that it It you you get time dependent solutions to time independent equations and not only for the ground state but for all solutions and the And and that's a system that can be very very well approximated in a laboratory So yes, it might eventually dissipate But it takes a very long time if you take appropriate precautions And In other systems Then sort of electrical is I mean the josephson phenomena Uh is much more So similar equations govern other phenomena and magnetic systems in Not only in superconductors, but in superfluids and and many other circumstances And in those circumstances The question of dissipation may be even less pertinent. So I think it's a I think I think it's a perfectly fine example And uh, it's only disadvantages that it's old and familiar and that's uh Uh, but but also at some point maybe maybe it's maybe it's you know, maybe it's uh You know the kind of perturbations it's robust against In the case of josephson junction Maybe is not as large as you would like because after all it is electrons that are electrically coupled and and so so But but but it's a pretty good example Yeah, so in this respect may you comment also because lasers have equations that are close to The time dependent josephson effect, right? Yeah, I think there's a similar that's right. There's a similar discussion for lasers although I think they are uh It's harder to make them clean cleanly non dissipative. I would say But if you could you uh, you might expect to get sharp phase transitions and the combination of rigidity and softness that's characteristic of spontaneous symmetry breaking There's but but I But it takes special precautions. I mean so so I mean there's a large literature on of course on laser phenomena of all kinds and there's there are strong analogies to phase transitions but uh well, I Think they could be sharpened. Yes. I do. I do think they could be sharpened and That that would be a very interesting thing to do, but I should say, you know, my my command of that literature is is not Professional so there may there may be a lot of things that people have done that I'm not fully aware of So there is another question by uh, jaffari can a timescale for a time crystal be as small as a plank Uh, well I don't know That uh, that brings in a whole raft of other questions. Uh, maybe maybe The appropriate response I can give is that Of course, you know at the very very broadest level we can say that uh, the big bang is a kind of Spontaneous breaking of time translation symmetry because we have the the equations the underlying equations as In most formulations that we know of not only within the standard model, but also in string theory Basically have time translation symmetry And yet the solution we live in does not an asymmetry and uh And actually there are some identifiable soft modes steve Weinberg has emphasized this and his approach to cosmology So, uh, so there's a little bit of that if you talk about cyclic universes. It's also possible but another possibility That's that that's more novel but much more speculative is that There may have been in the early universe all kinds of things might have happened in the early universe We just don't in the very early universe. We just don't know there might have been a period where you had not smooth evolution But a very rapidly oscillating behavior taking over for a while So a time crystal in the in the in the more usual sense where you have many oscillations But uh It's it's also interesting to speculate that under extreme conditions Of curvature So, you know at the center of a black hole for instance as well as in the early universe You might have new phases of spacetime that are crystalline in some sense and if Because you're talking about spacetime. It would be very natural very unnatural to just have crystals that are not also time crystals So so yeah, so I I think there's there's uh There is a small literature, but but it's an interesting possibility to consider time crystallization of spacetime itself And possible application areas would be black holes in the early universe Yeah, so, okay, so probably I take the chance to ask myself a question Is it possible? I mean, what would think probably an application of time pressure would be in synchronization, just, you know, you know what? Synchronization or just trying to synchronize different. Yeah, well Self-correcting ways to synchronize things Yeah, well in the in the context of of clocks for instance if you have something that's uh Robust to perturbations you can use it to feed back into the things that Drive atomic clocks and make corrections if they if they if they wander a little bit So that that that's that that's the atomic clocks. I mean, uh Several different applications have been speculated about in the literature I'd be very interested to hear at this conference what some of the more some more details But uh, one one possibility is that eventually when we have quantum computers, they're going to need to I mean all all computers need clocks that you know that do Operations where where they have to be synchronized across different modules And if you want to have clocks that are gentle and don't Uh interfere with the quantum mechanical behavior, you probably want to use some kind of time crystal clock if and uh, these Magnon clocks might have technological potential Certainly the authors of This paper and also there was another paper Recently from Helsinki Their low temperature group Mentioned that they have applications in mind, but but the papers Well, I didn't read the papers closely enough to see exactly what they had in mind If I'm not sure you can find out from those papers exactly what they have in mind, but you should be asking them not me I don't know they uh But so it's early days. I don't think we know What if any technological applications they will be but I think because of This combination of robustness to most perturbations But sensitivity to Selected kinds of perturbations Uh, those those are very potentially useful properties sensitivity for sensors obviously and robustness for keeping stable time And uh being able to synchronize reliably Adish Yeah, just to follow up on this Josephson junction question. So So it looks like the trend crystals have nothing to do with many body physics or even quantum You can have a completely classical system with just a single degree of freedom Well, uh, well, I mean the jokes. Well the joke As I said, uh, the people you can Different investigators have used different definitions or different different, uh, criteria for, uh Uh, what they mean by spontaneous symmetry breaking and Depending on how strict your definition is you'll have more or less Of the desirable features of or the interesting universal features of robustness and softness Now, of course the josephson effect is a many body is definitely is a many body effect It's just that we're focusing on collective, uh degrees of freedom that, uh Uh Can be treated To a good approximation, uh On their own, uh So and that's what makes it robust if it really is, you know, the delta is the phase of an enormous thing Enormous number of electron physical So, uh, so it's still it is a many it still is a quantum and is very much quantum mechanical There were h bars all over the place but, uh Yeah, but I I do think your remark is well taken that, uh, it certainly is possible and fruitful to, uh Think about, uh, classical dynamical systems that have this property Of, uh, solutions with less symmetry than the equations. Uh, of course, you know That's a huge subject in itself and a huge classical subject with the whole business that goes into chaos and, uh Nonlinear circuits and all kind of yeah and limit cycles. It's you know, it's a tremendously rich subject, uh, but most of that has to do with, uh dissipative systems and The kind of robustness and soft mode structure they have is rather different However, uh, you know, it's it's not An entirely different universe and I think one can one can cross fertilize between Those different ideas So this one this one more question Sorry, I just read it. I I'm not sure I really understand very well But say can a time crystal have a space crystal equivalent in a sense that you can do rotations between and just Transform one in the other. I think it relates to well, yes Often there's locking between space and time symmetry. So if you think about it in a traveling wave The traveling wave at any point changes in time at any Time changes as a function of space, but if you move space and time together in the right way It's symmetric. So you can have these locked symmetries and that's uh, that's definitely possible and there's There's a kind of you can imagine a four-dimensional classification of possible crystalline patterns And things like that. So in fact, that's where I started as a kind of formal investigation in group theory as to possible patterns, but the dynamics I think is has been has been especially fruitful And and and for the patterns by the way, there's a very highly developed literature Uh Of of of classifying that and so called bifurcation theory. Well, you see what how one pattern can change into another So there's a there's a very well developed rich mathematical literature Just ready for use. I think in the time crystal Take me In the time crystal context Yeah, so I should apologize Now because then the the q of the unanswered question is growing much faster than You know the speed at which I'm able to read. So I'm not sure we are going to Okay, so uh, tomas fischer Ask about If you say something more about, you know, you mentioned about the A clean distinction between the system and the drive. So Yeah, you just say so why is the drive? What is the system? It's just a purely theoretical point of view that can be checked or not No, no, no, it's it's not it's much more than theoretical It's I apologize with tomas. I'm condensing the because it was a long I actually can I can see the question here. Uh, the But it's it's not It's it's not it's not conventional at all. It's uh The thing is, okay, you put you have a drive and you have a system and they start by exchanging energy and the drive In general because of friction, uh, if you don't pump energy out of the system You'll just have the the the system heating up If you do take things out of the system, it's not closed and and you know, it's it's uh You shouldn't be treating it as a closed system. Uh, so the criterion is that you have you the the system settles down Into a state where it's no longer exchanging energy and entropy with the drive so Mathematically, it's as if you have an external a time dependent Hamiltonian of of a closed system It's implemented through a drive, but the drive is not exchanging entropy and energy with the system And so it settles down into the system settles down into a kind of autonomous behavior as if it just has a time dependent Hamiltonian and uh, the objective Correlate of that is That the system doesn't keep heating up that it that it forms that it falls into a reproducible equilibrium And it's it's properties uh Don't change anymore And uh, so so it it has settled down into a well-defined state And as you saw that can be phased transitions and So, let's see. Let's also ask Oh, sorry, sorry Go ahead. No, go ahead. Okay, uh, let's see. Let's ask, uh, is block oscillation in crystals can be considered Another example. Oh somebody, you know, somebody once told me what block oscillations are, but I forgot So I can't answer the question Yeah Okay, uh, I don't know but the general answer is to all these questions though is uh that If you use a very strict definition of time crystals, then you'll have fewer examples, but more consequences If you use a very loose definition You'll have hordes of examples, but very they'll have very little in common And they to me the dividing line is you want you really want to have this kind of robustness against a large class of perturbations and softness against some other chance Class of transformations that are connected to the symmetry breaking. So another At least you you tell me when we should stop. I don't know. I mean that we can go like this like this So another question is that in your talk, you put stress on lack of dissipation by our Chuck There are a lot of recent works on disability time crystal. Can you please comment on them? Well, as I said, if you if you, uh If you lower the criteria Then there are more examples, but fewer universal properties I would have to look at them sort of on a case-by-case basis to see where they fall Yeah, that's that's what I'll say, you know that If you use a looser enough definition, then Then you you you get back to Faraday and And that that's fine, but you should you should realize that You're not necessarily getting the full Uh Weight or implications of spontaneous symmetry breaking or because Really your system is not The closed system includes both the drive and what you call the system. So it just has less symmetry It's not a matter of breaking spontaneous. It just has less symmetry so So that that that's the issue whether whether you can identify a separate system that has less symmetry But is separated from from the drive and Maybe you can loosen that criterion to a Quite a bit and still preserve the good properties, but That would have to be examined case by case Okay probably I should apologize for all the people that could not Then I could not read the questions, but I think there are Constraints time constraints I got already emails from Icts system that We cannot go on so I really would like to thank for the To thank you a lot for the very nice and inspiring A lot. Yeah, thanks. Thanks for your interest and it was a real pleasure Thanks, and thank you very much. Yeah, and it's been uh, it's you know, it really woke me up this morning in a nice way well, okay Hope to see you in ictp in person. Maybe sometime in the future and Okay, yeah, and I guess now we're going to adjourn to another another room and then yes Yeah, so if you like maybe a few minutes like what do you think like 15 30 in about Yeah, a 30 minute break 30 minute. No. No. No. I was saying 10 minute break for eight minutes 10 minute break A 10 minute break is less wonderful, but I'll also do that. Sure Okay, I think the idea is that you yeah, just to interact with our students and then I will leave you All right. Very good. Thank you. All right. Bye for now. Okay. Thank you Bye. Bye


What's up everybody, it's Stas here. Welcome back to another video. So in this video we're going to be talking about two more stocks that I'm looking to swing trade here heading into the month of October in 2019. And this is kind of a follow up video to a video I made last week where I talked about three stocks that I'm looking to swing trade heading into the month of October. That video got some good feedback so I figured why not throw in another two to make it five total stocks that I'm watching and looking to trade swing trade heading into the month of October. So if you find value in this video, if you enjoy how I break down these stocks, tips, tricks about swing trading feel free to go down below, hit that like button, consider subscribing if you want to see further content from me and make sure to join our StriveSmart Discord group chat as well as our StriveSmart Facebook group. All of those are linked down below. So let's take a look at the S&P very quickly right now and you may be asking yourself, Stas, the S&P is selling off. Why are you looking to swing trade right now? Well, believe it or not, when the markets are selling off, a lot of stocks are selling off as well. And what is that doing? That's opening up margin of profit on a lot of these stocks. So I'm not against the stock market falling. I like it when the stock market falls because it opens up a lot of opportunities to swing trade stocks and maybe even buy stocks for the long, long term. And in long, long term, I mean three, five, ten years out, ten plus years out. But in this video, again, we're mainly focusing on swing trading. So looking at the S&P guys, you know, right now it's down about 0.7%. It's down about $21. And it seems like it's looking to test that 50 S&A here on the four hour chart. And we may be going down to that level that I've been talking about on the S&P, which is at around 29.50. So that is a retracement. If we just pull out my trend tool very quickly, my trend line drawing tool, that's a retracement of about 2.5% from the all time high. So with that 2.5% drop since the rejection at that resistance we got a couple weeks ago, you know, that opened up a lot of opportunity in a bunch of stocks. And it's currently opening up a lot of opportunity as the market continues to drop. And let's say the markets continue to drop over the next couple of days, next couple of weeks. Again, this is going to open up a lot of further profit margin in a lot of stocks out there in the stock market, which is why, honestly, guys, I advise you to just keep a watch list of at least 10, 15, 20 stocks that you're always watching. You're always breaking down. You're always doing technical. So this way, when the markets are dipping, you can run through those stocks that you're very familiar with. You can see, okay, this could be an entry point. This could be an exit point. And you can plan out your trades that way, right? So let's just hop into the first one that I am watching here, which is drumroll, please. The first one is guys J and J good old Johnson and Johnson. So this one is at a level right now where it's not 100% confirmed to pull up here to continue to run up here. It's at that point where it's close to a breakout. And let me explain what I mean by this. If we zoom out a bit, let's say to the one year one day chart, you can see that there's a clear resistance on Johnson and Johnson at around $131.50. Maybe you can say $131 flat that rough area right around there. So you guys can see now today, if we go to the intraday chart, we actually broke out of that 131.50 level of resistance we failed or actually we didn't fail yet, we're looking to hold it as a new support right now due to the pullback we're experiencing, most likely because the overall markets are getting crushed, which obviously is dragging down Johnson and Johnson. So on the 184 hour chart, if we go back, this could be a point in time where if we break 131.50, which we did again, as you saw in the intraday chart, and we pulled down and hold it as a new support, which we're in the process of doing right now, this could be an entry point if we hold it as a new support, and then start to climb back up, maybe test 132, maybe 132.50 and ideally into the 133s because 133, if you notice a couple weeks ago, back in the middle of August, this was actually a resistance point. So in my opinion, 133, if we did break that, that would be the first signal to potentially start buying into Johnson and Johnson. That's what I'm thinking as of right now, as an entry point for a swing trade. And it's very obvious you guys can see resistances all over here. If I just pull out my little tool here, you can see a strong resistance is going to be at around 139. You see another one at around 142. You see another one at around $144.98. I guess you can call that $145.  So let's say 133 we enter, we swing it all the way up to 140, that's going to be roughly a 4 to 5% margin of profit, you know, upwards of $142, that might be around 7%. And if we get to that high at 145, that could be upwards of 8% profit. So guys, one thing to keep an eye on, and again, I can't hammer this into your heads enough, take these with a grain of salt. Don't just buy these because I'm looking to buy them. Do your own research, do your own due diligence, make sure to understand what you're trading, and understand that the overall market could affect these individual stocks heavily, and this whole plan could go out the window if the overall market's continue to drag down, and that would obviously drag down stocks individually. So look, the markets, as we speak guys, they're falling down and down and down. If we break 29.50 and we start to drop, you know, all of these swings that I'm looking at right now, they might not be good entry points right now. But once the markets find a bottom, whether that's in a week, whether that's in a couple of days, they could be setting up for an entry point at that moment in time, which goes back to why it's important, like I said a couple of minutes ago, to have a watch list of 10, 15, 20 stocks. So even when the markets are selling off, you can always go back, check it, understand where the stock's at, is it at support, where the moving average is doing, is it at resistance, is it at a good entry point, is it a better time to wait? You know, this is very important when in terms of just tracking and keeping an eye on a bunch of different stocks. So again, you know, it's important to watch the markets, watch how everything is doing because the markets, the economy, everything that's going on right now in the whole global economy, trade war interest rates, that has a huge effect on everything. So the second one that I'm looking to swing trade here, not as juicy as J&J, but it's still been doing very well over the past couple of months is Chipotle Mexican Grill ticker symbol CMG. This stock in the year of 2019 alone, you guys can see here back in January, literally about eight months ago, this stock was $453 per share. Fast forward eight, nine months. Look where it's at now guys, $857 is where it peaked. We pulled down, we held that 180 SMA support on the four hour chart, which has been a support over the past couple of months, which is a very good sign. We popped, we got rejected near that high at about 857, 860 ish. That could be a temporary double top, which might be bearish in the short term. But now that we're pulling down and it's looking like we're retesting that 830 level, it seems like we're breaking that, we might be going down at the 50 SMA at this point on this four hour chart, which could potentially retest. But ultimately, I need for Chipotle Mexican Grill to hold this 180 SMA support on this four hour chart. If we hold this level here guys, you know, we start to maybe pop up. This could be a good entry point, 815, 810, you know, 820. And if the markets do end up dragging down Chipotle, which if you think about it guys, Chipotle doesn't get too affected by the market's performance. I mean, it does. Of course, a lot of stocks do in certain scenarios, but Chipotle overall, it's been doing quite well. And during the time periods where the market sold off, you can see it went from 720 to about 650 in May. But ultimately, it's recovered after every single correction that it saw, that it's seen at this point. So if we just pull down and hold, this could be another point where it recovers from the dip again, which it's done every single time, at least on this four hour chart in the past, right? So keep an eye on that. We may be getting the pull down. This could open up a nice entry point. Again, low 800s, you know, from 805, let's say, for example, we get in for a swing, we go up to 860. That could be around a five, six percent move. And of course, if we continue to hit those higher highs, you know, continue to smash, I believe those would be all time highs. If we go to the one year, one day, we'll see. Yes, that would be an all time high, you know, you could potentially get upwards of like eight, nine, 10% and even more intra-poly if you do get in on that dip. So those are just two more stocks that I'm looking to swing trade heading into the month of October. If everything sets up well, if the markets, you know, sell off and find the bottom and continue the upwards push, which would again, most likely influence these two stocks and the three other stocks that I talked about in last week's video, you know, that could be a good, you know, potential swing trades for October. So now that you made it here, guys, if you made it here, feel free to go to that other video I made last week. Go check out the three other stocks I'm looking to swing trade. I'll link that video down below. And that's it for this video, guys. If you enjoyed it, feel free to go down below, hit that like button, consider subscribing if you want to see further content for me and drop a comment. Let me know what are your thoughts on the markets right now. What are your thoughts on these stocks? I'd love to know. So I'll catch you all in the next video. Thanks again for watching. Peace out.