Thanks so much to Linda and to Lisa for inviting me to participate. I'm coming to you from the Miller Center at the University of Virginia. So I'm going to start a little bit talking about the Miller Center. So the Miller Center is a research institute. The Miller Center is a nonpartisan research institute that focuses on political history and public policy with a special emphasis on the U.S. presidency. We're part of the University of Virginia. And you can see there, our building, we're kind of housed off the ground in a really nice space that has free parking. Don't tell anybody that, because that is the most important thing at any college or university. I'm sure you all know. So we have a number of different programs that might be useful to accidental government librarians. And I'll kind of walk us through those through my presentation. The first one I'm going to start with is our American president website. So it's called the U.S. President. And this website is good for general users. This is not for your deep scholars that want to do scholarly research. This is for your students who come and say, I need to find some information about any given president. And this website has authoritative essays that are written or reviewed by experts and supporting materials such as speeches and public programs. So I'm going to just click on Lincoln as an example to show you. They all come up. They have the same template where they have across the top members of the administration. You can see everybody in their cabinet, major events, which is kind of key events by a timeline during the presidency, and then educational resources. If you scroll down, each president has fast facts on the right. And then you can see the essays in the middle of the page. So it covers, as you can see, campaigns and elections, domestic affairs, foreign affairs. HSA has an expert who has written or reviewed the material, and then there's supporting materials. So featured insights, these are public programs about Lincoln, about his presidency, about the Civil War, as well as speeches, these and photographs. And these differ, obviously, for each president a little bit. But this is a great site for students and for, actually, general interested public. Someone's like, I want to know more about Teddy Roosevelt's 1912 presidential campaign. Great, a great site to use. So moving on from there, the Miller Center also houses a presidential speech archive. Now, this is not a comprehensive resource. When Lisa gets to her resource, the American Presidency Project, which I think is what she's going to talk about, that is a comprehensive, like all the public papers of the president. This is kind of the highlight of presidential speeches. And it includes text from George Washington to Donald Trump, audio from Franklin Roosevelt to Donald Trump, and video from JFK to Donald Trump. To give you, so here you can select which president you want to explore. And then if you click on a specific page, you can see they sort of come up with the video, the audio file, a description of the speech, and then the transcript. These are very useful for finding a famous speech if you want to compare speeches from presidents. So what John Kennedy's speech about the Berlin Wall in Berlin versus Ronald Reagan's speech in the same place 30 years later, so that sort of thing. We're working on making it possible for users to bulk download materials from our website, so when that is enabled, that would allow people to do kind of textual analysis of the presidential speeches. So going on from that, the Miller Center is also home to a presidential oral history project. And this is in-depth interviews from members of the administration from Jimmy Carter, Ronald Reagan, George H. W. Bush, Bill Clinton. We are getting ready early, probably next spring we'll launch the George W. Bush oral history project, and by launch I mean we'll open it to the public. That has already been done. We have, I think, about 60 to 80 interviews for that, and that will be open to the public. And we have just started the interviews for the Obama, for the Barack Obama oral history project. We also did a special project on Edward Kennedy, as you can see his name there as well. And these are interesting too, so if you, so I'm going to actually, let's click on, we're going to click on Bill Clinton, just to kind of show you, and then it will list all of the interviews for that particular president. If you click on a specific interview, you can see they come up in the website. They are here for users. You do not need to come to the Miller Center. Everything that is open for the oral history project is available online. And users can search these, obviously, they can also download them. So if you wanted to see, we offer PDFs of the oral history interviews, as well as a briefing book, which is the materials that we give to the interview, before we do the interview. So they have some sense of what we're going to talk to them about. And these interviews cover specific events from a presidency, but they also get into detail on the workings of a presidential administration. So how decisions were made, how information flowed through an administration, and how an administration responded to events. We don't have at this time a great index for these oral history interviews. And so sort of, lamely, the best thing to do is kind of do a command F on any given interview. So say you want to see where the Cold War is discussed, for example. It would be to kind of go through the people in a presidency, the secretary of state, the secretary of defense, and kind of search that, the electronic transcript to find out where that topic has been mentioned. And those are just a really good inside first-person account of these presidencies and kind of what went on in them. The final project I'm going to talk to you about is called the Secret White House Tapes. So these are about 5,000 hours of audio from the Franklin Roosevelt, Eisenhower, Truman, Kennedy, Johnson, and Nixon presidencies. But the bulk of the audio comes from Kennedy, Johnson, and Nixon. The audio tapes are from the National Archives, and they are in the public domain. So the Miller Center does not own those. Anybody can access them and listen to them. But the Miller Center is the only place transcribing and contextualizing the tapes. The tapes allow users to listen to phone conversations and meetings between the president and his advisors or visitors to the White House. The tapes are complicated, and they are great, and they're complicated for a number of reasons, one of which is that each administration did it differently. So where they recorded, how they recorded, how the tapes were processed by the National Archives, they're all different. And so the naming conventions are different. How they're organized is different. And so if you have a scholar who is interested, or if you yourself are interested, and you really want to get more into the meat of the presidential secret White House tapes, I would actually recommend for you to get in touch with me, because depending on which presidents you're talking about, they're kind of different strategies and different ways to approach them. But for the casual users, you can see here on my screen, we have these featured recordings. And these are available under our educational resources. And actually, wait a minute, before I go there, I'm going to show you, when you research the tapes, basically, you can see here, we just have all the audio. Like it's just here, and we have an infinite scroll on our website, which I don't love, but that's the way it's done. And so you can just kind of go through and see, so you can see from conversation to conversation, different dates and different topics that are discussed. And you can also search your process. So you can see if I just searched on civil rights, and there you can see conversations that are specifically about civil rights across different presidencies. But for the more casual user, what we've done is under our educational resources, we have highlighted different conversations. So if I go back here, you can see here, these kind of featured recordings, wherein our scholars have transcribed them, and then they put them, match them to the audio. Generally, like Lyndon Johnson is actually very easy to understand, but a lot of the other recordings, it can be hard to understand what they're saying, if you can't also see the transcript at the same time. And so these are under our educational resources on our website, but I'm going to just bring up one quickly and play it for you. It's kind of a short one, but it's a good one. This is a recording between Lyndon Johnson and Senator Richard Russell, who is I believe from Mississippi, a close kind of mentor of Johnson's. And this is a conversation that took place in March 6, 1965, about the ongoing war in Vietnam and kind of the upcoming escalation.  And you can obviously hear it and see it at the same time. Well, I'll have the military assistance and the, I don't know, deck to trouble with this finally. The great trouble I'm under. A man can fight if he can see daylight down the road somewhere, but there ain't no daylight there. There's no end to the road. The more bombs you drop, the more nations you scare, the more people you make mad, the more embassies you get made. We're going to wind up with the people who are mad as hell with us that we're saving by being in there. Well, they'd say, I'm ahead. It'd be lucky, but they'll all say I created it.  And I want to see you. And it got three women want to see you. Well, give all of them my love, bye. As you can see, these do a great job of kind of bringing to life history. So they're useful for scholars. They're also useful for teachers in the classroom with students as a way to kind of help history come alive. You really get to hear a lot about, learn a lot about the president's personality, how they interact with people, the way they negotiate policy compromises, for example. And so it's just a really unique resource that people can kind of delve into on that. So that's it for me. I'm sort of trying to keep my time constrained since there are four of us to present. But if you have any questions for me, I'll go to the chat and I can answer them. But also, my email address is my last name, blackfordatvirginia.edu. And so if you have, I've gone through this kind of quickly, if you have any specific questions, feel free to email me. I'll put my email in the chat and I'm happy to help you. Thanks so much. So I'm Catherine Hornam, the special collections librarian at the Washington Library at Mount Vernon. I'll just give a quick intro into what we are. Our library was actually built five years ago. There was previously a research center on one of the administrative buildings on the historic estate. But five years ago, they decided to build this beautiful new facility to really be a center for the study of Washington. Very much in the model of the presidential libraries, even though we are not an official presidential library, we are complete. We are our own nonprofit institution separate from the National Archives. But if you go to our website, mountvernon.org slash library, you can see there's some pictures of our beautiful building. And then I'm just going to run through a few of the resources that we have. Obviously, unlike the other presenters, we do not have information on all of the presidents. We have a very specific focus on the first president towards Washington. But what we do at our library, in addition to being a research library, we host a lot of speakers and events. We have research fellows who come for any more from one month to six months. And we also have an education and leadership department that do their own programming. But what I thought would be of most use to you all, I wanted to switch over and talk about two different initiatives that are hosted by our library. The first one is the Papers of George Washington, which is also being hosted in conjunction with the University of Virginia and their Papers of George Washington editing project. One of their editors works here in our library. And this project has been going on for, coming up on 50 years now. They are going through and transcribing every piece of correspondence that George Washington has ever written. And they are both publishing them in physical volumes and then putting them on a database that will be accessible, text searchable for everyone to use, along with their copious notes and cross references that really have opened up a whole new world of researching George Washington. So if you go to our website, we have a description of the project. There's a way to link to the Papers database, which maybe I won't go into now. But again, that has fully transcribed all of the correspondence of George Washington. And you can, on the website, can read a little bit more about that project. And so as part of our partnership with the Papers of George Washington, once the printed volumes are complete, the goal is for all of the paperwork related to this project to be housed at the Fred W. Smith Library. So once the project is complete, we will have at least a scanned copy of every single piece of correspondence George Washington has ever written. And that will be a great resource for us and for all of the scholars who come here who want to research George Washington. Our library is also home to a digital research, Digital History Research Center. And there are a number of initiatives that come out of this center. The most important one, or the one that might be the most useful to you all is the George Washington Digital Encyclopedia. And there's a link to it here. In addition to the Encyclopedia, you can see that there's a podcast. There are some interactive maps, interactive maps of George Washington's world, which sort of is a great digital history project tracing everywhere that George Washington went in his life. And this is very helpful for, do you ever get very specific research questions about where was George Washington during this time period? That's a great resource. But going back to the George Washington Digital Encyclopedia, what this is is essentially a really big database full of articles on everything related to George Washington's world in both the colonial era and the founding era and the Revolutionary War. So this is everything from who were his generals, who were his secretaries, who were the enslaved people who worked at Mount Vernon, and they are all organized both by subject, subject and title kind of broken down into these different groups such as things about the American Revolution and the presidency will also have its own section. And these articles, they have all been either written by somebody on our staff or a professional scholar, or they have been written by an undergraduate student and then they have been edited and approved for publication by somebody who has a PhD in history. So it's actually also been a really great kind of community outreach and kind of crowdsourced encyclopedia all by history scholars. So this is a really great resource, great place to send people instead of if you're trying to encourage students to get off of Wikipedia and go to a more reputable source that was kind of the big impetus between the digital encyclopedia is that we could direct those sorts of inquiries to our website. And then for the research library itself, we have a list of our databases which is really a great jumping off point for all of the research tools that are available at our library. And you can see on our database listing that some of these are websites that were created by Mount Vernon. These are the ones listed as Mount Vernon open access. A lot of the databases are open access so they're just made by offsite, they're offsite resources, but they are open to the public. And then there are also a number of databases listed that are subscription only and these are databases that we provide access to when scholars come and use the computers at our library. In terms of actual primary sources that are in our special collections, visual resources and archives, there are three main ways to find our collections online. The first is our library catalog. This is where all of our general collection as well as our rare book collections and a number of our manuscript collections are. This is our founding fathers library consortium in partnership with two other famous historical houses in this Northern Virginia area. We have a standard library catalog. This is where again, you can search for all of our rare books. Some of the highlights of our collection and we do have 104 volumes from George Washington's original library. A lot of these are books that he actually received during the presidency. So there's some really great things that will come up when you search there. And then I'm gonna turn it over to Becca Baird who's gonna talk a little bit about the two other ways to find our primary sources which is our archives-based, finding aids database and the digital library. All right, so I'm just gonna jump off of what we're cat left off. So we are both, Catherine and I both work at the Washington library. Before I launch into searching our collections I do just wanna talk a little bit about my collection that I work with and the difference between what is our special collections and what is our archives. So the archives that I work with are the archives of the Mount Vernon Ladies Association. A lot of people don't know that Mount Vernon is actually not owned or operated by the federal government or the state of Virginia but they're owned by this nonprofit, the Mount Vernon Ladies Association. Here's some information about them on our website. It is a unique organization because it is made up of only women and it has been since they purchased Mount Vernon in 1858 but it's also significant because it was pretty much the first organization in the country that was dedicated solely to historic preservation. These ladies got together to try and save George Washington's home. So what's significant for us at the Washington library is not only do we have some great resources about George Washington but we also have this great archive of information about the Mount Vernon Ladies Association which is what I mostly work with. Then to go back to previous page. So to search all of our collections and there's a couple of jumping off places you could go to our special collections and archives page which kind of outlines the differences between all of the three collections for primary sources that we have. So you see the special collections here which holds mainly Washington family papers so any papers written to or from George Washington and Martha Washington and the rest of the Washington family would be in special collections and then the archives of the MVLA and then the photo archives are separate from special collections. So those are the kind of our three primary source collections there. So you can search our finding aids for all three of these big collections in our archives space. We use archives space as our database. A lot of you might be familiar with this already. So you can get to that through our website through that couple of different links. So this is our archives space page. I apologize that we don't have our branding on it yet. Our IT department is still working on that but at least we're available on the web now. So you can see our three repositories here listed. So you can go, you can search, do a search for all across all three of the repositories or you can do just a search in one of the three whichever one you're looking at. So I'm gonna go into the archives just to give you a few ideas of other places that you can search. So if you're looking at the collections right now from some of the collections from the archives we have about 21 finding aids available. And one of the great things about archives space is that you can link to digitized material on the web because we also use OCLC's Content DM Digital Asset Management System to host our digitized material. So just to give you a quick example of how these are linked, I'm gonna show you one collection. This is publications of the Mount Vernon Ladies' Association. You can see here once you click into the collection all of the finding aid details that you would normally find in a finding aid. And then over here to the right all the different series. So just to go into this series here that breaks it down even more into the folder level here and then if you click on something specific that you wanna see such as this historical sketch of Anne Pamela, our founder. This big icon right here shows you that there is a digitized version of this publication available. So if you click on that, it will take you to our digital collections page where you can see the digitized version of this booklet and scroll through it. So this kind of brings me to them. One of our other great resources which is our digital collections at the Washington Library. I'll take you to the main page of that. This is a great way to search and see all of the items that we have digitized here. A lot of the George Washington manuscripts that we have are available through this as well as a lot of the family papers, a lot of images of Mount Vernon and a significant amount of information about the MVLA as well. And as I said, this is, we use OCLC's content EM system for this. And then the last thing I kind of wanted to show you is that we also have some material on Femio. We have some video. We recently had some material digitized, a lot of our film collections. I wanted to show you how those are kind of linked to each other.  We had almost all of our film reels that are in the collection digitized recently within the last few years. And now those have all been organized and placed here. So they're described in archive space, but then if you scroll down, you can click on specific ones and you can see here's the digitized version.  And here's a good example of one of our videos that shows a visit of King George and Queen Elizabeth in 1939 to Mount Vernon. So I think that there is another way to search on archive space. If you just want to look at digital material you can see here. Anyway, that's just kind of an introduction to our special collections and archives that we have here at the Washington Library. So that's it for me. I think I'll just hand it over to Lisa next. You know, as the final presentation, mine's gonna be quick. I just wanted to give everybody an update about the American Presidency Project, which you can see here has a brand new look. It's much more user-friendly. I know that this was a big project for John Woolley and Gerhard Peters at the University of California, Santa Barbara. And you can see here all types of presidential documents that you can search. And the majority of this collection is post-SDR. And you know, this is an amazing resource because students, if they wanted to do some text mining, could grab a document and put it into the JSTOR text analyzer or something like Boyant. There's a big section on statistics with mapping and data visualization that I think librarians and students are going to find useful. There is a media archive as well that can be searched. And then a section of content by president. So, you know, I encourage everybody to take a look at this new interface. And now I'm gonna just go in to PowerPoint and just show you some of the new content that will be included are Donald Trump's tweets, press poll reports, 2020 campaign materials. And this final slide are some articles that discuss resources as they exist now for presidential studies as all of our presenters have told us, you know, websites, content are constantly being updated. There's a list of research guides and also Hine Online has a great new collection about the JFK assassination with I think over 600,000 records in there. And that's all I have and I'll hand it back to Linda. All right, thank you very much everybody. This was wonderful to see what your different institutions are doing. If you have questions, feel free to put them in the chat box. I guess one of my questions was, is there any big projects coming that you have in the works or things that you? I just wanted to comment that the presidential or the secret White House tapes, which we also call the Presidential Recordings Project, we are getting ready to kind of redo that part of the website in an effort to make it a little bit more user-friendly than it is right now. So just kind of FYI, it won't happen, you know, before the new year, but just we're hoping to make that a little bit more, a little bit clearer to user kind of a combination of just the audio and then the transcripts in the audio a little bit easier for people to be able to navigate. So keep your eye out for that. And this is Catherine. I would just add special collections. Our main project right now is just describing documents, which anyone who works in archives can understand. Our archives-based database just went public this year. So we're sort of working to get through the backlog and catch up on some things and sort of beef up those item level descriptions to make them more accessible to people, especially adding subject level access points for topics such as slavery, you know, Native Americans, the presidency, the farewell address, these sort of access points that people are often asking reference questions about. Could you talk about how people can access the physical collections or the process for doing that? Maybe that might be of interest for some. Sure, Fred to Beatsmith Library. We're open by appointment only. We don't qualify researchers or make anybody submit any kind of like letters of recommendation and all of that. If people just go to our website, there's a form or there's a general email that people can use. We're open Monday through Friday, nine to five. You just have to make a research appointment to get you through the gate. And then our reading room, both our general collection and our special collections materials are available. So people are looking for specifically the Washington-era manuscripts in the special collections. You can also feel free to reach out to me directly or reach out to Becca for the archives materials. And I've been getting, some people are sending me private questions actually. Could Lisa talk a little bit more about what kind of statistics are included in that section of the site? Okay, so there is, you can look at election results by year. I hope you see that. You got it, okay, great. So you can look at election years. You can look at breakdown by party going back to 1789. And then in the data archive, there is so much here. I think this is great. Again, for librarians, researchers and students, there's information about congressional relations, approval rating. And then we see, we have approval ratings here from Eisenhower through Trump. So basically, whatever your researchers might be looking for, it's pretty likely they're gonna find something useful in here. We've got how many news conferences, presidents participated in, executive branch growth, elections obviously, there's some more data here. So there's a lot here. Great, thank you. And let's see, Anna was saying no questions, but a giant thank you, this was an eye opener. Thank you for coming, Anna. Thank you for coming, and thanks everybody for coming. Thank you, everybody.


First of all let me thank you for inviting me to give this lecture series. So, this is first of three part lecture series. Today I will mainly talk about causality in quantum field theories and general quantum field theories and this lecture is. So, today's topic is. So, these three lectures are mostly based on three papers. So, these two with Tom Hartman and Sachin Jane and the last paper with Hartman and a PhD student Amir Tajdini. Quantum field theories are integral part of our lives and they have certain properties. For example, if I if somebody gives me a Lorentzian quantum field theory, it should have few properties. First of all, obviously it has to be Lorentzian variant. Secondly, it should be unitary and also it should be causal. Similarly, if somebody gives me a quantum field theory in Euclidean signature, first it has to be Euclidean invariant. It should be reflection positive and also crossing symmetric. So, in the next lecture, I will explain this properties in more detail. So, from the title of the lecture series, you probably can guess that I will mainly focus on causality. So, it is an open question how causality is related to all these properties of an Euclidean quantum field theory. In some sense, this question was addressed in 50s, 60s and 70s by Schwinger, Weidmann and Osterwalder, Schroeder. So, the precise statement is the following. If you have a good Euclidean quantum field theory and if you perform a continuation, that gives you a good Lorentzian quantum field theory which has all these properties. But the point that I want to address is the following. So, what goes wrong if I have a quantum field theory in the Lorentzian signature which violates causality, what actually goes wrong in the Euclidean signature? Before I proceed, let me make couple of comments on causality. Causality is the Lorentzian concept for obvious reason. If you want to talk about causality, you need to have light cones. The main point that I want to focus on these lectures is the following. Causality can impose non-trivial constraints on quantum field theories in Lorentzian signature. There are Lorentzian variant quantum field theories which actually violate causality and I will give you one example. And the next point is in quantum field theories causality is an operator statement. So, a theory may appear to be causal in the vacuum, but it can violate causality in non-trivial states. Because causality is a statement about operators, so a theory should be causal in any state. And requiring a theory to be causal in any state actually impose non-trivial constraints. Here are couple of examples. Please feel free to ask questions if you have any. Yeah, I have a question. Of course the list of the triaxioms there is gauge theories are those triaxioms are incompatible. Lorentzian unitarity and causality cannot hold at the same time engage theories. You are excluding gauge theories for your presentation? Not really. What kind of theories are you talking about? Whatever. Quantum electrodynamics. It doesn't work in quiddiq. It is not quiddiq, so let's start with quiddiq. You see, d is not satisfying the saxons. No, I mean they are incompatible in gauge theories. No, I am surprised to say so. It depends on which observables you look at. No. It's a theorem by Whiteman. No, it's not. Okay. Let me start with a scalar field theory with shift symmetry. So let's start with this action. So in a paper by Adams, Arkane-Hamed, Duoski, Nicholas, and Rathaj in 2006, they argued that this coefficient mu has to be positive, otherwise this theory cannot be UP completed. So obviously this coefficient is non-enormalizable, so this is an effective field theory and their argument is basically if mu is negative, this theory is sick and there is no UP completion. And this constraint actually played an important role in the proof of C theorem in 4D. And let me give you a classical proof of this bound. So classically phi equals to zero is a solution of this theory, but let's consider a somewhat non-trivial solution of this theory. So let's consider this solution where this is a constant vector. Oh, that's a solution of this. I write down the equation of motion. This is a solution. You can just check. So what I want to consider is basically propagation of this perturbation in this background. So again I can write down equations of motion for del phi. So it goes like this. In the plane wave basis, this is simply, okay. Now for simplicity, let's take C to be a time-like vector. So my C is C0 and 0 and K is omega. If I plug that in here, that gives me. So if mu is negative, the speed of propagation is greater than 1. So that's one reason phi mu has to be non-negative. So in this original paper by Adams et al, they had another beautiful argument phi mu has to be positive from by considering 2 to 2 scattering of phi. And they basically showed that unitarity tells you that this has to be positive. An important point about both of these proofs is that they make sense only in Lorentzian signature. So one might ask what goes wrong in the Euclidean theory if mu is negative. So this classical argument is not obviously sufficient for that. Yeah, this is a very rough argument like there is a actual proof of this statement. I know they had the argument which is basically unitarity and I think this was the argument. But this argument is also given in the paper. It leaves some unsatisfactory feeling because you say, okay, this background, I can see this background where phi 0 grows at infinity. Is this actually a very good background? Should I, if something here kept on this background, maybe I should not be very concerned. They tried to answer this question in the paper by like taking a bubble inside. So this solution is valid in some bubble and then it goes to 0 outside that bubble. They tried to make that argument in the paper that like, yeah, you can probably make this precise but because they had another argument, I guess they didn't actually. It makes you move space like that from. Yeah, you can do that. Yeah, then it will not change sometimes. You'll get the same result, yes. So another example comes from gravity. Consider gravity in let's say 5D where I have the Einstein-Hilbert term. I have some negative cosmological constant, though I don't need this term. Let me just skip it here and I also have some higher derivative correction terms. So this is the Goswami term in 5D. So this is a ghost recombination of all possible R squared terms and M2 is some mass scale which is far below the Planck scale and C2 is some order 1. So just as a Lagrangian, you can just check that this is partuitably consistent up to some scale M which is parametrically higher than M2. In a paper in 2014 by Edelstein, Kamanhoe Edelstein, Maldesena, and Zubayadab. Can you explain why it is not, why it is a top form of M2? Yes, so it's just, you just take, because there is an overlap. One, two. Yeah, so it's basically something like square root of M2 times M Planck, something like that. Okay, so in the paper by Kamanhoe Edelstein, Maldesena, and Zubayadab, which I'll refer to as KEMS, come to 2014, they studied shock wave solutions in this background, in ADS. So you have something like this, where u and v, they are null coordinates and z is the bulk coordinate. They basically studied shock wave solutions in this background. So you have some function of z and y, a delta function. So this is a shock wave. So let me draw a diagram. So this is v, this is u. So this shock wave is propagating this way. Now let me take a graviton, probe graviton, and send it in this background. So when that graviton hits the shock, there is a jump, and let me call that jump. So bulk causality requires that this delta v has to be positive. If delta v is negative, that means there is some time advance. So in this particular paper, they send gravitons with various polarizations, and they showed that delta v is always positive if and only if C2 is zero. So that means pure Gauss Bonnet theory is a causal. So now from the point of view of effective field theory, this has the following meaning. So as I said earlier, so I have scale m2, m-flank. As I said earlier, this is perturbatively consistent up to some scale m, which is parametrically higher. So nively I would expect that new physics should appear here to make everything well behaved. But this argument tells you that actually new physics should appear here and fix this causality violation. So it's basically if you just take this theory, if I just give you this theory and if you just study perturbation theory, then you'll see that actually it breaks down at this scale. That would be called the strong copy scale, which is not necessarily capable of the field. Yes, so basically m2 is basically like if I have a theory and I integrate out everything above m2, you should get something like this. But just as a Lagrangian, it doesn't require that. But at the classical level, this theory with the square and the curvature, it is not maybe it's the case, but there's no prior reason that the characteristic cone is still the null cone. For Einstein theory, we know that the characteristic cone for the propagation is the null cone.  Yeah. So if this classically is not causal? That's right. You can make that argument classically, but again there is another argument which shows the same thing. So this is a very classical rough picture, but there are other arguments which shows that. But what I say is that there is no reason to require the usual causality for such a theory. Yeah. But like if you study, let's say, Graviton scattering in ADS for this theory, that should have unitarity, things like that. Yeah. Classical level, yeah. So this is classical argument, but there are analogous quantum argument which gives you the same result. Yes. This classical argument can have problem, but that quantum argument is there actually. So the goal of today's or these three lectures are the following. So understand causality quantum field theory. This is what I covered today. Then as I said earlier, causality violation in Lorentzian signature tells you that there has to be something wrong in the Euclidean signature. Then I'll consider CFTs in the greater than two dimensions to show that reflection positivity plus crossing guarantee that the Lorentzian theory is causal. Then I'll use that to derive constraints on interactions of low dimensional operators regardless of what happens in the UV. And fourth, I'll show that these constraints are intimately related to the averaged null energy condition. So I'll provide up to of the averaged null energy condition from causality. So this is today. So this is lecture two and this is lecture three. So in quantum field theory causality is a statement about commutators. So this commutator should be zero if they are space like separated. As I mentioned earlier, this is an operator statement. So if I plug this commutator inside any correlator, that correlator should also be zero. So because of that, a theory may appear to be causal in the vacuum but in some non-trivial state, this condition can actually be non-trivial. So in a quantum field theory, whenever we compute some correlation function, generally what we do is we start with the Euclidean theory, we compute the correlators, and then we perform a decontinuation to get Lorentzian correlators. So Euclidean correlators has certain properties. First of all, they are single valued. So let's say if I take a endpoint function. So this is a single valued function. Second is its permutation invariant. That means if I change orders of the operators in the Euclidean correlator, that doesn't change the function. Sorry. You exclude fermions for simplicity. Yes, that's right. And third is this function is analytic. And it's analytic and it doesn't have branch cuts as long as all the points remain Euclidean. The fact that its permutation invariant, that means basically an Euclidean signature commutators do vanish. Then I perform the standard analytic continuation to get Lorentzian correlators. So for that, I take one Euclidean direction arbitrarily and I'll call that tau and I'll analytically continue that to it, where now t is real. So that leads to one question. When do a set of Euclidean correlators define causal theory? So this question was answered by Osterweiler and Schroeder and which goes by the name Reconstruction Theorem. Reconstruction Theorem tells us that well-behaved Euclidean correlators after analytic continuation leads to well-behaved Lorentzian correlators. So let me write down EC for Euclidean correlators. So by well-behaved Euclidean correlator, I mean they are analytic from coincident points. They are SOD invariant, crossing symmetric, reflection positive and obey certain growth condition, which is not relevant for our discussion. And by well-behaved Lorentzian correlator, I mean they are invariant, causal and unitary. So the point of view that I want to take is somewhat different. I'll only assume some limited information about the quantum field theory. So I'll assume something about the, I'll assume something about few low dimensional operators and I want to know if that set of information is compatible with causality or not. So in Reconstruction Theorem doesn't actually give an answer to that question. It just, it tells you that well-behaved Euclidean correlator will give you causality violation, but it doesn't tell you exactly what, like if, if I have a causality violating theory, it doesn't tell you what goes wrong exactly. So that leads to analytic continuation. So this Euclidean correlator G, I said earlier that it's an analytic function of positions. So if my tau is real, then this is an analytic function. So, but as a function of complex tau, so this function G can have intricate structure of singularities and branch cuts. Do you think, do you are talking about only one time or all the times? Are you ordering the times in any way? So in the, in the, in Lorentzian signature, yes, that's, that's what my goal is. In Euclidean. So in Euclidean signature, so this is, I'm just starting with Euclidean, Euclidean correlator which doesn't care about the ordering. So all the points are Euclidean. But when you go to continue? Yeah, so then in the Lorentzian correlator, I'll, I'll care about the ordering. And yeah, I'm going to talk about that, yes. M tau, you have tau 1. Yes, yes, yeah. Yes, and okay, so for simplicity, I'll just, I'll just anecdotally continue one of them, not, not all. So because of this, because this function has branch cuts, so this analytic continuation is actually ambiguous. That sounds problematic, but actually that's not a bad thing. You can actually show that each choice that you make in, in this analytic continuation translates into a particular ordering in the resulting Lorentzian correlator. So basically, that means because of this branch cuts, operator ordering does matter in the Euclidean signature. So these branch cuts are actually responsible for non-vanishing commutators in the Lorentzian signature. Let me give you one simple example. Let's consider this two-point function. So in the Euclidean signature, I can just compute this two-point function. For simplicity, let me call them O1 and O2. So first, I compute the Euclidean correlator. Let me call this G. So complex tau. In the complex tau plane, there is a branch cut at ix and minus ix. So if I want to compute the Lorentzian correlator, I'll start from the Euclidean one and I'll analytically continue. If in the Lorentzian signature, O1 and O2, they are space-like separated, then basically I have to analytically continue from here to let's say somewhere here and there is no ambiguity. However, if in the Lorentzian signature, O1 and O2, they are time-like separated, then I have to start from here and analytically continue somewhere here. And because of the branch cut, so because of the branch cut, you can do it in two different ways. So one will give you the time-ordered one and the other one will give you the anti-time-ordered two-point function. So what are the rules? So first of all, the one important thing is whenever you hit this singularity, only after that you have these two choices. So that means this singularity is responsible for non-finishing commutators and not that is responsible for non-finishing commutator between O1 and O2. So what are the rules for this analytic continuation? So if I have a singularity, I can either pass this singularity from the left or from the right. If I pass this singularity from the right, that gives me time-ordered commutator. If I cross this singularity from the left, that gives me anti-time-ordered. So this one gives me O1 Tx and this one gives me, so this discontinuity across the branch cut, that basically gives you the commutator of O1 and O2. Now let me give you one more involved example. Let's now consider four-point functions. Probably it does tell you something about the CFT but for us only thing that matters is if it's non-zero or not. Or it can be non-zero or not. That's the only thing that we care about because that's the signature of causality violation. Let's now consider this four-point function. This is T, this is Y. So this T is the Lorentzian time and this is some arbitrary direction. So my O1 is here, my O3 and O4 they're here. Let me draw the light cones and my O2 is let's say somewhere here. So all of the O1, O3 and O4 they are space-like separated and they are at T equals to zero. Only O2 has some non-zero time component. So as now this coordinator in the complex tau-2 plane has this structure of singularities and branch cuts. So first singularity appears when this O2 hits this light cone of O1. So that's I times O2 minus O1 and the next singularity appears when this O2 hits the light cone of O3 branch cuts. And there is one more singularity because of this O4 but let me ignore that. Similarly there should be singularities on the lower half plane. So now consider this case when O2 is time-like separated with respect to O1 and O3. So it's somewhere here. So because this is inside the light cone of O1 and O3. So in this language so I should start from somewhere here and I have to analytically continue to this point here. So when it's basically above both of these singularities. Let me just somewhere here. So there are obviously you can immediately check that there are four different analytic continuation that you can perform. First one is this one. Let me call that A. So this goes this passes this singularity from the right also this singularity from the right. So this is when this operator O2 is time-ordered with respect to both O1 and O3. So that's O2, O1, O3, O4. The second thing that you can do is this. So you can analytically continue this way. Right of this then left of the other singularity. So as I said according to our rules O2 should be time-ordered with respect to the operator responsible for the singularity that's O1. But it should be time anti-time-ordered with respect to O3. So this is O3, O2, O1, O4. The next thing you can do is this one. Left of this singularity then right of this. So this is B, this is C. So you are crossing this singularity from the left. That means O1 and O2 they are anti-time-ordered. So O1, O2, O3, O4. So O2 is anti-time-ordered with respect to O1 but time-ordered with respect to O3. And the fourth one is this one where the collator is completely anti-time-ordered. So there are four choices for analytic continuations. And in the Lorentzian signature you can write down these four different Lorentzian collators. Now let me make the statement about causality. Need this board. So let's now consider a special case of the last example. Okay, so again I have four operators. So this is time, this is y. So I have an operator psi and operator O, another psi. So this is the light cone. And I have another operator O which is time-line separated with respect to psi. So it's somewhere here and it's approaching the light cone of other O. So I have another operator O. So in the language of analytic continuation, so this is what I'm doing. So again I have two branch cuts. So basically I am approaching this singularity. So I'm approaching this singularity. And again I can do it in two different ways. I can choose to go from left or from right. Now first consider the simpler one. So this is the coordinator O, O, psi, psi. So when I hit this singularity along this path. Yes. That actually doesn't matter. Yeah, I can do that. I care about the commuter. So it will give you a different sign. That's it. It's approaching it from below. Yeah, from below, yes. So it's basically like, I basically want to study this singularity by approaching it from the below. So when you hit this singularity, at that point the O, O commutator becomes non-zero. So this thing becomes non-zero when I hit this singularity. Now if I follow this path, as I said earlier, this singularity is fixed by light cone. So as long as I'm below this singularity, this is zero. And that means this is, this coordinator is causal. And that's not very surprising. This is, so this coordinator is kind of fixed by the light cone structure. Now let's look at this coordinator. This is psi, O, O, psi. So this quantity psi commutator of O and O with psi, this becomes non-zero when I hit this singularity, but along this path. But because I'm crossing this branch cut, the position of the singularity is no longer fixed. So basically I'm going to the second sheet of this Euclidean correlator. And on the second sheet, this singularity can actually move around. And this commutator becomes, or this coordinator becomes non-zero when I hit this singularity, but on the second sheet. So now the statement of causality. Now let me erase the trivial one. Let me now look at this analytic continuation. So two things, when I do this analytic continuation, two things can happen. So on the second sheet, this singularity can, let's say, move in the upward direction somewhere here. So if that happens, then this coordinator becomes non-zero when I hit this point. Now in this diagram, that point is somewhere here. So that means this coordinator becomes non-zero at a later time than you expect from the light cone. That means there is some kind of time delay. And that's all right. There is nothing wrong about having a time delay. However, if this singularity, so this gives you, however, if this singularity moves in the downward direction, that means this correlator with the commutators becomes non-zero. So let's say somewhere here. But that means, so this operator O and this operator O, they are now space-like separated. But even then, this is non-zero. That means this is a causal. Or you can say that there is some time advance. So the statement of causality is basically this singularity on the second sheet cannot move in the downward direction. So this is not allowed. So let me summarize. The first statement is I don't know of any example where it moves at all. So the state like the causality tells you it cannot move in the downward direction. But in principle, it's allowed to move in the upward direction. But I don't know of any example where it moves. In fact, in CFT2, we can actually show that this singularity doesn't move at all. So starting from the Euclidean correlator, causality on the first sheet is trivial. The non-trivial statement about causality is a constraint. Singularities move around in the complex tau plane when we other light cone branch curves. So in the next lecture, I'll use this setup to derive constraints on interactions of low-dimensional operators in conformal field theories in dimension greater than 2. And next, I'll comment on how these constraints are related to the operational energy condition. So let me stop here. Can you remind us what determined like there was some tacit assumption that the first sheet corresponded to both branch cuts go in like you drew them. Why then? We have to note on the right. Okay, so this is kind of a cartoon. Where did this get broken? So it's not like it's not like you can actually forget about these branch cuts altogether. So what you can do, let me, so let's just consider the two-point function that's easier. So if I have a single, if I have this singularity and if I just do two things, I compute this function and I just compute this function and I can just match these two can check if they are the same or not. So you can just check that they are because of this singularity that they are not the same function. So we draw a branch cut somewhere here. So I'm drawing these branch cuts. You can actually just forget about this branch cut. You can just follow this path and find out that function here. So all I'm doing, I'm just saying I'm approaching this imaginary axis from the left or from the right. So that's the only thing I'm doing. But why, where was the symmetry between left and right broken? So it's not as... You said that when you approach from the right, from the right it's trivial and from the left non-trivial. So why is this symmetry broken? So it's not like, okay, probably there is a symmetry between which I call trivial and which one I call non-trivial. Yeah. So there has to be some formulation of this, not in terms of right and left, but in terms of some other. So, okay. What you can do, you can... Somebody can just choose to draw them on the right side. Then basically you can just do the whole thing. So in my rules of anticontinuation, I can just move the left to right and right to left. It's basically, it's just identical. So the reason I'm drawing in this particular way, so that the trivial anticontinuation, that gives you the time-ordering. By trivial, I mean like just I'll take a point from here and I'll just adequately continue this way. Start from positive tau and then you rotate. Yeah. So that gives me the time-ordered collator. But I don't have like, I can just choose the branch curves in this direction and then I'll just call this one time-ordering. That's it. You made a comment before concerning that you are going beyond the of the van der Schrader continuation. Reconstruction, what is the point here? We don't have to re-exploring the other regions. So for the reconstruction theorem, basically you need to know all the collators and everything. So here I'm just, I have a single collator and I can talk about causality of that. Like if that collator is, will give you a causal Lorentzian collator or not. So it's basically, I only have this, if I start with this limited information, even then I can talk about causality. That's my point. So in other words, basically I don't care if this comes from some quantum field theory, which has all the good properties. Only thing I can, the thing I want to show, if I have some collator and it has this, and it has this attic properties, if it's consistent with causality or not. I don't care if it comes from some. What do you assume on the Euclidean side? So on the Euclidean side basically, okay, so I assume everything on the Euclidean side, but only for this collator. I don't care about all the rest of the collator that you can have on that particular theory. So it's basically, in that sense, it's some limited information. Can't you say that, can't you say that you will, unlike Astrovaldi Schrader, who reached some qualitative conclusions about what is good and what is bad, you will reach some quantitative conclusions, like you will be able to derive some constraints on the data of your theory. Yes. Some numerical answers about what can happen and what cannot happen, and this was not contained in those theorems. Yeah, that's right, yeah. So next week I'll move on to CFT, when I can actually use this setup, where this setup will actually give you non-trivial constraints. So what that tells you, it doesn't matter what kind of theory, what kind of CFTs you are looking at, all of them should obey those constraints. You mentioned that you will use also reflection positive up to this point I haven't seen. Okay, so this is now, so far this is a statement about like what does it mean to be a causal Lorentzian correlator. So next week basically what I'll show that if I start from Euclidean theory and let's say if I start from this collator in the Euclidean signature, if it obeys reflection positivity and crossing symmetry, then this is guaranteed, that this will not move in the downward direction, that's guaranteed. I have a question about the rules you assigned, is it just there and a deeper reason for how you read all the rain from the way your analytics continue? So there is basically reconstruction theorem does one more thing. It actually tells you how you can analytically continue one Euclidean collator to get different Lorentzian correlators. So the rules that I described today, they are basically equivalent to those, the one that you get from reconstruction theorem. So in reconstruction theorem what you do, you use some I epsilon prescription, which basically shifts this singularity either on the on this side or this side. So you can do this analytic continuation in two different ways. Either you can choose to move the singularities or you can choose to move the path which you take to do the analytic continuation and both are equivalent. So all I have to check is basically I am not all I have to check is basically this prescription is in agreement with the known I epsilon prescription. And it agrees with the I epsilon prescription. Yes. Since there was a question, can you clarify, which I think is possible to clarify, so to, in which sense, to which correlation functions, to which observables would your discussion apply if we had a gauge here, something like young meals in 40 degrees, some really complicated. Whatever I said should be like, if you managed to give me a four point function in the position space, everything I said that should go through. Well, which of which operators? Any scalar of, any Bosonic operator will do. It shouldn't matter. It will not be reflection positive. It should be gauging their interpreter, right? Yes, yeah, yeah, that's right. It should be gauging their interpreter. Yes, it has to be gauging, that's right, yes. And probably it's, we can still allow for myonic operators, but you have to be more careful. This is for a scalar, so I'm sure there is a easy generalization of this for fermions. But fermionic or otherwise, I think that's easy to fix. Yeah, it's more important to see if it gauging the other problem. Yeah. And I believe that this will apply really engagement otherwise you will never have it. Never have it, I think. Just some question. Yeah, even to those kind of long angles, this discussion of what is the main of analyticity for wind functions here, because we have configured this in the space and it's kind of unknown for many points. And it's about geometry of this, all of these discussions about analyticity and convexity envelope for this domain. It's anything else? So this analysis question is that you get. So because the cases that I consider today, they're kind of simple, because I'm adequately continuing only one point. So but there are known subtleties, if you just try to adequately continue all four points, let's say, there are known subtleties. It's possible that this one-to-one correspondence between number of analytic continuation and number of orderings in the Lorentz signature, that one-to-one correspondence might not be true if I adequately continue all of them. So there are subtleties, yes. No, but mathematical questions, you have some domain in that function, I want to see you as a values of point. Yes, so I'll actually comment on that on the third lecture. That will actually be important for the discussion. Because you are assuming that you have only cats here. This is not known in general. Yeah, that's right. Yeah, but you see, this is a minimal set for flow. You see, it's the other way around, the way I understand it. If you find that this particular commutator is not causal, the theory is not causal. It does not tell you that every other commutator will also be causal. And what you ask is a much more general question, is whether the entire theory, but what he wants to see is, if you have a constraint, this one commutator is not causal or not. If one commutator is not causal, the theory is not causal. But even for this particular thing, it's assuming something concerning the analytic structure of the four-point balance, which is not known. Yeah, but you can do it for the two-point function. Two-point, okay. But there is an old theorem due to a Bartman-Coward-Weidman, which tells you a domain where the Euclidean correlator is a single-valued analytic function. So can you see this domain in your consideration somehow? Not in this. To find the domain of the model, which is the angle of this, the film. So not in this construction, but so when I'll prove average knowledge condition, there it will be important. So I'll discuss that. So this is a minimal setup. So this is, I guess, too restrictive. So we might not be able to see everything from this setup. Yes, yeah. You're talking about local operators. Yeah, yeah, they are local operators. Yes, that's right. Yeah, I should have mentioned that. Yes. So you can see the account to filter. It's okay. For example, define Euclidean where it can define gauge variant operator. So because I'm not studying from a Lagrangian, it's basically all I have is basically some gauge invariant local operators in the theory. That's it. Because I guess there exists quantifier, so we don't have gauge variant local operators. Then you have to worry. I was wondering how much of this would go through. Yeah, I haven't thought about that. So I'll probably, yeah, I have to think about that. I'm not sure. Okay, well, if there are more other questions, then I'll be preparing to clap. So let's thank speaker again.


From before the beginning of time, mankind has shared stories. For centuries, communities have gathered together by the light of the campfire, sharing legends of heroes and villains, monsters and demons, of hidden treasures, and adventures in mystical worlds. These stories all share the same purpose. They keep the spirit of adventure alive, as the legends of the past are retold for each new generation. In the modern era, our legends are bigger, grander and more immersive. At their core, though, they're still based on that same spirit of adventure that humans used to share around the campfire. This is the origin of one such modern legend. As a young boy, Shigeru Miyamoto didn't have a television. It wasn't that his family couldn't afford one. It just didn't seem like a priority. Instead, Shigeru spent his childhood years roaming the hillsides of his hometown, Sanobe, in Japan. He would spend days exploring the rocks and the trees, lakes and fields, learning about the world through every new plant and creature he encountered. He liked the experience of going out without a map, discovering things at his own pace. His adventures were filled with mystery and the excitement of the unknown. This occasionally got him into trouble. Shigeru would often find himself terrified of an enormous dog that would bark and strain to its chain whenever anyone drew near. Thankfully, the chain never broke, but that didn't stop Shigeru from thinking about what horrors might unfold if ever the dog broke free. One day, young Shigeru found a cave nestled away on a remote hillside. It was large, dark, and Shigeru realized that if he was going to explore it properly, he'd need some kind of light source. Running home, he found a small lantern that would provide enough light to enter the cave. Stepping across the threshold and in amongst the cold, wet rocks, his little lantern illuminating the space, Shigeru was struck with a sense of wonder and discovery. He had found this cave all by himself. Nobody else knew it was here. The possibilities were endless. He felt like a true explorer, mapping out a corner of the world all by himself. It was exhilarating. Years went by and Shigeru grew into manhood, but he never lost that childish sense of wonder with the world around him. Working as a game developer for Nintendo, Shigeru had the task of coming up with new ideas for inventive and original video games that his team could work on.  As such, Nintendo wanted new games that couldn't be beaten in a single sitting. They had the possibility of building enormous free roaming experiences where the player could spend months exploring the same game world without having to start all over again. Shigeru liked the idea of making a fantasy game, something that gave the player a sense of the unknown and a spirit of adventure. He remembered back to his time in the cave and got excited, thinking about the possibilities. What if he made a game that captured the thrill he felt when he was exploring all those years ago? He started brainstorming ideas for a game that would let you roam across an expansive open world, finding hidden treasures, caves, and secrets. This game wouldn't have a clear goal from the start. It wouldn't be as simple as progressing right, as in Super Mario Bros. Shigeru and his team filled the game with caves to explore, with dungeons to traverse, and puzzles to solve. This new game would be about more than just quick reflexes and fast reaction times. Players would succeed only by being brave, exploring everything, and seeking out hidden secrets that helped them progress. Building one world wasn't enough either. Shigeru and the team had the idea of adding a second, altered, and rearranged map to the game, where items and caves would be found in completely different locations. To even the most seasoned player who'd beaten the entire game, this was meant to feel like an endless, expansive experience. Shigeru liked the idea of starting the player off exactly where he had started all those years ago, by tiptoeing into a cave without any indication of what might be waiting there. Inside, players found their call to adventure, much as Shigeru himself had been filled with excitement when he explored the cave in the countryside near his home as a child. This approach also meant putting Shigeru's mascot character to one side. He decided that including Mario and as many games as possible was a fun way to connect his work, but this time around, he needed someone less recognizable. Shigeru wanted a protagonist who felt a little more like a blank slate, so that the player could invest in the character and put themselves in his shoes. Using some of the available save data on the Famicom Disk System, players could enter their own names into the game and could feel like they were the hero in the story.  Shigeru called his creation a garden of sorts, but one that players could roam around in endlessly, placing it in a draw when they'd finished and returning any time they'd like. And with that, the legend of Zelda was born. The game has gone on to become one of the most influential titles in the history of digital media. Even to this day, over 30 years later, players are still finding new hidden secrets and tricks to exploring the game world. Shigeru's vision was truly realized. His experience in the cave all those years ago has now been shared with millions of players across multiple generations. The moral of the story is simple. Be adventurous. Go out into the world and try new things. Find your own path and see what wonder and joy awaits you that others might overlook. You never know when you'll find some incredible inspiration. As you journey, be sure to share your adventures with others. After all, the trials that you pass through will become the legends that the next generation looked to for inspiration.


Okay. Thank you everyone for turning up to the 2.30 session for the Open Programming MiniConf. We have a couple of JVM talks for you now. The first one is going to be presented by Steve Dalton who is going to be explaining why rumours of Java's demise have been greatly exaggerated. Please make him welcome. Thank you. I've been a Java developer for some time and I come to these conferences and hear lots of interesting ideas about Java, particularly in the Linux community. I thought today I'd just do a little talk on my view on where Java's going and sort of dispel this myth that Java's dead. Maybe some of you might have thought that. I'll just quickly show your hands. Who here's coded some Java in there? Who currently uses Java as their main language? Quite a bit less. Other JVM languages? A little bit. Okay. Cool. I'll just crack into it. In case you don't know, Java is more than just a language. Java is a language. It's a virtual machine and it's also a process called the JCP. Lots of people don't realise that who aren't Java programmers so they think of the language a lot. It's chopped the bottom off on my screen. I'm sort of giving my conclusion here right at the start but I thought, what the hell? A lot of people say Java is dead but long live Java. The language itself is struggling a little bit. The JVM itself is doing very, very well. It's everywhere, pretty much where I see.  Java the language, I'd agree maybe it's on the ropes a little bit. The JCP, I'll get on to this a little bit later but it's in a bit of strife. First of all, JVM, if you're running on, I'll just talk about Linux here. There's really only a couple of main options here. I've completed a couple more here but it's really the open JDK and the Sun Java JDK. I think some Linux destroyers have started calling it the Oracle JDK now but I know Ubuntu is still the Sun JVM. There's the open JDK. There's also this thing here called GNU Classpath which also was GCJA, lots of different names. One that's been in the news recently, Apache Harmony which does have a JVM component to it. That's in a little bit of trouble as well which I'll get on to. Really, if you're on Linux, if you're running Ubuntu, Debian, Open JDK, Sun JDK are really well supported. They're in the repos, it's a Snapget install. Very easy. Also, a little one to watch is the Dalvik. It's not really a proper JVM. It's a virtual machine but it's what powers our Android mobile phones. Listen, talk about that running on Ubuntu native. There's also talk about having Android on Ubuntu running on regular Java. I'll get on to Java, the language.  It really started in 1990 with a project called the Stealth Project. This guy, Patrick Norton, became the Green Project. Early on, Sun were looking at mobile devices, set-top boxes mainly. There was a language called Oak, which actually ran on these boxes and if anyone's familiar with any of this. As we progressed through the years, it became a different project name. Names changed. In about 1995, it became Java. They released JDK 96. JDK 11, things started to gain momentum. We had inner classes, Java beans, a lot of these things we sort of take for granted now as Java programmers. This is 13 years old now, a lot of this. Java 1.2 came along. We got Swing, JIT, compiler, which made things a lot faster, collections. They also established something called the Java community process, which was a kind of standards body to navigate the various Java specs. 99. Java got pretty popular, two million downloads. Java Platform 2 had lots of confusion about version numbers. Was it 1.2 or 2? It had this little thing called J2ME, which didn't really go anywhere. I don't know if anyone's done any J2ME programming. 2000, Apple came on with Java. 1.3, bits and pieces. Java 1.4 was a big one, included better exception handling, web start preferences, things like that. If anyone remembers all of this, it's like a little bit. It's quite interesting for me going back through all of this. J2E, J2SE5 was a big one. In 2004, we had things like generics, annotations, order boxing, numerations, all sorts of things came in. A lot of them I actually didn't use for quite a long time. I still don't really like generics. We'll get on to that. 2006, J2SE6, which didn't have a lot of changes in the language, but quite a lot of performance improvements. This is the one that most people are on these days, unless you run an old application server that needs Java 5. A little important thing happened this year. We had this Java 7 project again. That was four or five years ago now. OpenJDK started the actual JDK itself from the compiler, the JVM. A lot of that was open sourced. Then, basically, I'm getting to a point here. We had a few little things, 2007, Java FX. Anyone seeing Java FX here? No. Bits and pieces, 2009. Then this thing came along Oracle and sun merged, which we all got a bit nervous about. 2010, a lot happened. In the meantime, the language hasn't really progressed a lot. People are getting quite nervous about Java. It hasn't really been a big year for Java. Negative and positive. A lot of things to worry about. This is where people have got very concerned recently. The Java 7 roadmap was pretty much, well, not abandoned, but really cut back. They dropped things like Java FX script, which caused a lot of trouble with some people. It was quickly forked. Oracle tried to sue Google. I think that's still ongoing. I don't know if anyone knows much about the case, how it's going. That's still ongoing over the Dalvik and patent breaches. Apple decided to deprecate Java in OSX. That's the little one that came through. Any people running Java on OSX here? Generated a fair bit of bad press. I don't know if this was related, but then they donated it back to the Open JDK project. IBM moved to Open JDK. The JCP process basically turned into a complete mess. I just switched off a little bit halfway through and then just got back into it. It lost a lot of Java people. It got so complicated. People left the ... I'll get on to JCP in a minute. Anyway, apparently in 2011, we're going to get Java 7. Apparently in 2008, we're going to get Java 8. I have a pretty low confidence level on what's going to happen. I'm standing very negative at the moment. My talk was supposed to be upbeat, so I'll get on to that. A lot of innovation seems to be stored in Java. Generics caused a lot of trouble. Closures were supposed to come in Java 7. We're getting closures, but they're not closures in what I can see really. Meanwhile, .NET is doing very well. It's carrying on with innovation. Dynamic languages are on the functional programming. It's definitely back. Is anyone here doing getting into functional programming? I know I'm starting to, trying to. Many people I work with are.  The community has actually found a way. Despite all of these problems, there's a lot of other alternatives on the JVM. One of my personal favorites is one called Groovy. A lot of people describe it as super Java. It's basically Java with all the things it should have had a few years ago. It's a dynamic language. It has a very nice clear migration path from Java. If you don't know Groovy, you can just rename your Java files .groovy. Compile them up with Groovy and then gradually start making it a little bit more idiomatic. It's very well established. It's using some big organizations. I work for the Suncourt Bank. We've got it all over Suncourt. Thanks mostly to a guy called Paul King who's one of the Groovy authors. There's a recent addition to it called Groovy++ which makes it static. People that don't like dynamic typing, you can make your current static. It's suddenly typed. There's a whole load of nice little projects that run on top of Groovy. Some of you may have heard of Grails. Grail or Gryphon is a swing Gryphon. Gaelic is a nice little framework for running on the Google App Engine. If anyone's doing App Engine stuff. And Jeepers, this one down the end here, a lot of people say Jeepers, but Jeepers is a concurrency framework. Next we have Scala. I've neglected to mention here before. These are basic canonical languages. The canonical version of the language is on the JVM. That is the version of the language. There's nothing else. Scala is either one. It's statically typed, functional or imperative. You can choose. There's a nice little progression if you want to get into functional languages bit by bit. Concurrency is built in. It's quite famous for being used in Twitter now. Twitter moved a lot of less to Foforubi, I believe. Well, some of less to Foforubi to Scala. Foursquare is it as well. Although I find Foursquare really unreliable, so I don't know if that's a great advert for Scala there. It has a little framework called Lyft for doing web apps along with lots of other frameworks. The third one is Closure. Does anyone here use Closure? Who there? That's nice. Closure is an interesting one. I'm only just getting into it myself. It's a dynamic. It's based on, it's a Lisp. So that's a bit scary to some people, but I'm finding, I never did Lisp at uni. I'm finding Closure quite interesting. It's functional. Concurrency, it's very good at that. So that's one of its big strengths. And it has a few frameworks already. Composure for doing web apps. I don't even know how to say that. Leningan, it's like a Maven type dependency framework. And there's some other languages in the JVM languages that are basically port. So we have JRuby at the top there. Jython. I don't know if many people are using Jython at the moment. And this one here is Rhino, which is a JavaScript information for Java, which is quite well used.  I probably haven't covered all of them here. There's quite a few. Burjang seems to be getting a bit of attention, which is an Erlang port. Phantom here. This one's rather interesting. Is anyone done Phantom? I knew you would. Yeah, you can compile it up on the .NET machine and also on Java and also compile to JavaScript as well. Resin is PHP. Go-Sew is a language that they use for guide wire, if anyone's used guide wire. And then along with it, we've got all these other ones. Jasko, we can guess what that is. Jsqueak is a small talk implementation. Mira is a modular JRuby, I guess you could describe it as. Nullop is an incredibly dynamic language based, its strength is testing. Jackal is TCL on Java. Frinks is a nice little mathematics DSL, which I don't know if anyone's played with. It's got great little Android app. Play around with maths. And there's a whole load of others. And you can create your own DSL if you want. And I think Tom might talk a little bit about creating your own JBM languages next. Finally, Java, the community. Well, I won't get onto JCP, but one of the good things about Java has a strong community. Lots of different libraries, IDEs are excellent. So we have Eclipse, everyone knows about it, but also IntelliJ is now open sourced. NetBeans, open sourced. Plus you can use pretty much every editor will have some Java mode. I did include Emux. It's a whole load of Java open source projects out there. A good place to look is the Apache Foundation, CodeHouse, Project Kenai is the sun now Oracle. I hope for all of these things. Also a lot of stuff on Bitbook. It's seen as they've been bought by Atlassian now. Lots of people putting Java things on there. GitHub, of course. We have a lot of web frameworks. I won't go into all of them. Grails is the one everyone knows about. There's many more. That's GWT, GWT. Lots of people using Wicket at the moment by the looks of it. Spring Roo got a bit of interest recently. They were doing the thing at Yao in Brisbane. If anyone went to that talk, that seemed to be very popular. Play, which I find quite interesting. Never got into anyone doing play? No. There's a whole load of so-called enterprise tools sitting on the Java stack. There's many more than what's in this page, but there's some big companies using these.  They seem to be going quite down quite well. HyperX is a great logging monitoring enterprise app. Finally, I'll just talk a little bit about the JCP. I haven't gone for time. The JCP is basically what drives the Java standards. There's something called the JCP, the specification request JSRs. The actual JCP has its own JSR to describe the JCP itself. If you want to know about JCP, you can look at that JSR. I can't remember the number. There's over 300 of them. As I said, they've been going since, I think, 1996. There's also a thing called, so JSR is made up of a reference implementation of the functionality person they call the Technology Compatibility Kit, which is how they prove that the JSR meets the spec. There's an executive committee that votes on all of these JSRs. That sounds pretty good. What's the problem? Well, the last year or so, there's been a lot of problems in the JCP. One of the things that has been in the press a bit is the Apache Foundation. They've had problems getting a TCK license because of incompatibility between licenses. Oracle don't sound like they've been particularly helpful in the whole process. We've had people leave the JCP, all sorts of negative press on this whole process, which has actually given Java a fairly bad name on it, so. So where are we heading? I'm not sure here. JVM is a very solid platform. As I said before, it's everywhere. Toolset is pretty awesome. The community is still actually very strong at the grassroots. People like ourselves, there's a little doubt about the language. People are saying it's the cobalt of our time, which might not be such a bad thing, but yeah, it's not sure where it's going there. Really, I haven't got a clue what Oracle are doing. There's all sorts of people trying to second guess what's happening internally in Oracle, but we're not sure there. My predictions, probably most of these will be false, but I think the JCP process is probably dead. Java 7.8 will probably be out. I'm not sure if anyone will really care much. Groovy's being used more and more. So I work in Groovy, so I would probably say it's the best one, but I think it's going to replace Java. In a lot of cases Skylar is also very popular. Closure, I'm not sure about that one. We'll see. I think they talk about these big 100 core CPUs and the way concurrence programing is going. Maybe that'll do well. We may see some forks in the OpenJDK. Not sure there, but there's a huge, there's a huge question already about the patents. So Oracle have already muscled up a little bit on Google with their patents, and that's a big worry. So we'll have to just watch this space there. And maybe we'll get Google go on Android or something crazy like that if they have to back down. I'm not sure there. If you want to hear more about my, on these various ramblings, you can listen to my podcast if you want. It's called Coding by Numbers. We're also on iTunes. I'll just open it up to questions if anyone has any questions. I'll try my best to answer. So questions for Steve. How can Groovy go well if Java the language starts to decay? Well, Groovy actually doesn't really rely on a lot of the Java 7 stuff that's coming out. Groovy already does closures. Pretty much everything Groovy Java 7's bringing. Groovy already does. I think there's a diamond operator in Java 7 which Groovy will take advantage of. So would it start to become less backward compatible, less interoperable? You mean with the new Java 7 stuff? I think they're tracking the Java 7 stuff already, the Groovy guys. So they will support the Java 7 stuff, but I don't think it really matters that much to actually most developers. The answery question, yeah. How much do you expect invoke dynamic to aid some of those dynamic languages you listed? Well, there was the, I think when all these dynamic languages came out, especially the JRuby guys, they were saying this is going to speed up considerably the dynamic languages. But from what I've read recently, the speed is actually not going to be as great as they originally expected. So I think a lot of the performance optimizations have been done in spite of, despite invoke dynamic. So I'm not an expert in this field, but I, from what I gather it's not going to be a massive speed up, but so that's why they're not so concerned anymore about the Java 7 stuff. There was, for a while, there was a lot of stuff on hold and they were saying until Java 7, until Java 7. But maybe that's not so important now, but it will help, I think, not orders of magnitude like people were talking about. I don't know if you could answer the question, but talking about where Java is going and the implementation of people taking on Groovy, what do you think about systems like IBM, WCM and etc that have heavily tied into Java? Do you seek IBM turning around and starting to use something like Groovy? Well, Java basically invested pretty heavily now into OpenJDK. They had quite a lot of developers on the Harmony project. They had six developers. They've switched them over to OpenJDK and given some more developers. So they're fairly, it sounds like they're pretty serious about OpenJDK. I actually didn't know a lot about OpenJDK until I did this talk and did a little bit of reading up on the process behind OpenJDK and there's basically two son engineers, well now Oracle engineers that control the whole OpenJDK commits. Apparently that's loosening up a little bit, but I'm guessing now IBM coming in there, maybe that will be shared a bit more. So I think IBM are pretty much, they're definitely serious about Java and they've pretty much come down on the Oracle side of the camp there. So I don't think it's going to go away there. Okay, more questions? No, everybody, please thank Steve Dalton for his talk.


Let's get over to our man, Mr. Fred Ernest. Fred is the president and CEO of Vistagold. We happen to own Vistagold. Vistagold has been working on a project in Australia, the Mount Todd Project, and we're going to talk to Fred about the updates on this project. Fred, welcome back to TFNN. Thank you, Tom. So, you know, you're doing a lot of work. So, I saw your press release. I saw, you know, if you can give the audience and the, you know, shareholders a little update of what's going on, that'd be awesome, Fred. Yeah, thanks, Tom. You know, earlier this week, we announced that we've completed an internal scoping level study to look at and evaluate a smaller-scale version of Mount Todd, at least on the front end. You know, this is important because, you know, Mount Todd's a huge project, 7 million ounces of reserves, but it's got a huge price tag. And we have completed an evaluation looking at a 15,000 ton per day operation capable of producing something on the order of 150 to 200,000 ounces of gold per year. But building a project at this scale with contract mining and the capital costs could be, are estimated to be less than $350 million. This is really important. It opens a door to a whole other group of companies that either couldn't afford a $900 million CapEx for being a partner or perhaps it's those who just said it was too aggressive. And we're really excited about the results of this study. It preserves optionality and it opens up a whole new door to the way we could develop Mount Todd. Well, in particular, you know, Fred, the way that, you know, just economy is in general across the world, it seems that it's really cool that you could get a piece of it, you know, with the realization that as long as, you know, the economies keep going while the bottom line is that then you can ramp this up. Let me ask you, what does contract mining mean? Well, instead of us buying the mining fleet and operating it with our own employees, we would contract somebody like Keywit or any other number of companies in Australia that specialize in mining open pit using their own equipment. So that's pretty cool because that's just like any type of developer that when you can subcontract out, I guess you're the expense ratio, you know, definitely have a better expense ratio going forward. Would that be correct? Well, what it does is it reduces your upfront capital costs and it reduces your risk as far as being able to deliver because you've transferred that risk to the contractor. Nice. Okay, I get it. I get it.  And, you know, the aspect that seems that commodities in general, you know, this is the first time in my trading career that I've seen actually car companies going after copper. Okay, so it's like, okay, you know, it's almost like the companies in general understand that commodities are going to be worth more money. When we take a look at inside of Mount Todd, is Mount Todd mostly gold, silver, copper? What is the ingredients inside Mount Todd? Yeah, it's almost entirely a gold project. How cool is that? We've got a very small amount of silver. There is some copper mineralization, but it's so such small proportions that we have no plans to recover it, just is not worth the expense of trying to do that. Oh, for sure. No, listen, it's great that it's gold. It's amazing. It's actually all gold when you actually think of it. And Fred, what is the aspect of, so let's say that, you know, you have companies that start getting interested in it, right? Then what would be the ramp up in order to basically start the first, not to start the first pull, but basically what would the ramp up be going forward? Yeah, so with this new study completed, a smaller project is obviously less complex than the project that we completed the feasibility study on. Yes. It's cheaper. You don't need as big of equipment. The lead times are shorter. So we expect that, you know, from the time that we could sign an agreement, reach a transaction with a potential partner that we'd be looking at still about a year's worth of engineering and design. But then instead of being 24 months for building commission, I expect that we could actually build in commission and something closer to 18 months and maybe even a little bit less than that. And what do you picture? I know you want to negotiate the best deal for your shareholders, but, you know, without actually getting into big details, what do you think the positioning would be? Meaning that how much do you have to, you're not giving up anything. There's going to be a flow coming into Vista Gold, correct? And then going out. So if you could just explain to us how you could envision that. Yeah.  But the idea would be that the amount of money that they would pay up front to earn in to their share of the project would be sufficient to cover all or most of the capital costs that we would incur to fund our portion of it. So the strategy is to execute a transaction that would allow us to essentially own our portion of the project going forward without having to dilute our shareholders further. And you've been very good at that for the last long time. Can you explain to the audience, some of the folks that don't own Vista Gold, Vista Gold folks, by the way, trades on NYSE under the American. It's VGZ, our McCanada VGZCN. Can you explain to them like your debt structure? Yeah, we have no debt. You know, we've been, we have roughly 120 million shares issued and outstanding, which is considerably less than most of our peers. We've been very cautious about money that we've spent. We've been very cautious about going to the market, raising money, diluting our shareholders. And we, you know, in part because we as a management team are shareholders and, you know, we pride ourselves on running a pretty tight ship and trying to do things that make our shareholders money. You know, in the age of, you know, culture, we talk about culture a lot in companies in the world in general. It's amazing to me how far Vista actually goes back with the same type of culture that you have managed to get this far and have no debt. That's almost unbelievable in the mining business, right? It is uncommon. It is uncommon. You know, we're, we're continually approached by people wanting us to, you know, give us a royalty or take a stream or offer us a debt. Sure. You know, it's just that's giving away shareholder value at pennies on the dollar. We just don't see that it's good business. And listen, folks, okay, Fred's going to be up in, up in Toronto next week, Fred, right at PDAC, right? Absolutely. So all you folks up out there, come go visit Fred up in Canada, all you folks in the United States that are going up there. I can't make it this year, but I know I always see a lot of you folks up there. So check out Fred at his booth and wouldn't willing to talk to you. And don't forget, folks, it trades on the American VGZ. Check it out. Go to VistaGold.com. Fred, you have a great one. Safe one. Thanks so much for the update. I hope you have a really great show next week. Thank you, Tom. Thank you. Have a great one. Have a safe one. Stay right there, folks. We'll come right back.


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