That seems to work. So shall we begin? I would like to introduce you to Alex Reicherschmeyer, Debbie M. Fenboy, who just happened to run into us yesterday out of nowhere. So he will talk to you about the publicity team, how you can help, and how we can help you. OK. Thanks. So thanks for showing up. And as said, I'm Alexander Reicherschmeyer. By coincidence, I'm not only a fanboy who joined yesterday's project. I'm also kind of founder or unofficial leader or whatever inspiration to others of the publicity team. And well, now here I am to talk a little bit about the publicity team and what you can do for us and we can do for you. A small warning, you might have seen that just my notebook crashed after a second. I can't see my own slides right now. So if I look constantly on my own slides, it's not because I don't know them. It's just because I want to know what I'm actually showing to you at the moment. So well, let's see how it works out. So well, what I plan for today is a small introduction, who we are. So an important point, how to actually get in contact with us, what we are actually doing, so that you actually know why you would to contact us, how you can help us. And then a list of open issues which might get solved during the DebConf or might get solved later. So let's start with who we are. Well, while I'm talking about the publicity team, I should tell you that there are actually two teams. The publicity team, of which I created here and surely incomplete list. I basically looked at our IRC channel and looked who has been active in the last time. And then I found out that I forgot something by looking at the mailing list. And I'm sure I forgot also some other people. I'm pretty sorry if anyone considers himself part of the publicity team and I forgot to add him or her. Anyone in the audience? Good. Well, as I said, we have the publicity team. And on the other hand, we have the press team, which considers of some members, sorry, Schultze, Mike Reichler and myself. We have also one assistant, Paul Weiss, who is not here. And who just became a member two days ago, one day ago. Well, at the start of the conference, Francesca, you might also know that I'm standing alone here on the stage. The others are a little bit shy, but sometimes I can convince them to stand up and wave to you. So be nice to them. So now we have two teams. The interesting question is, why? Well, the publicity team is, as I have shown you, there are many members. And basically, everyone can join our list, join our LSE channel, join their own ideas. That's how the publicity team works. People joining, trying to help, coming with their own ideas, doing things I've never thought about before. For example, Francesca just started organizing scheduled question and answer sessions with different teams. That's how the publicity team works. It also means that everything is done. We are public channels, public mailing lists, and go, everyone can join. Sometimes it takes a little bit of time to draft an announcement or something like that. That's how the publicity team works. So the press team, on the other hand, I've shown you before, has just a few members. So it's strongly structured. All the members are official delegates, thanks to SAC. And that's needed because sometimes they need to be able to speak on behalf of the project. Journalists show up, ask a question, and want an answer within hours. There's no time to propose a GR and let the project decide on it. That just wouldn't work. So we need to have some people who can do their very best to speak for the project. And that's why there are delegates, and that's why there are so few of them. As I said, we are contact point for journalists. And our email alias is private. It's not the public list. In fact, I think every Debian developer can read the press mailbox on the master server. I'm not really sure about that. But it's not the public list. That's my point. That's the difference between the two teams. But of course, we work closely together. As you can see, I'm a member of both teams. So is Michael. So are Francesca and Pap's. And well, that's just why we have the two teams. So the important thing, how to contact us. As said, we have an ISC channel, Debian Publicity. You can just join. No password, no anything. Just join. Be happy. We have a mailing list on alias, which you can just subscribe. Was that a question? OK. We have a mailing list, which you can also subscribe to on the alias system. As said, we have press at Debian org, which is a private alias, if you have something, which you would not like to be immediately known. Because one small problem we have is that the public mailing list is also read by some journalists. It also happens that, say, kind of fish announcement we are drafting on the publicity list and based their own articles on an old draft. Please? Yeah.  The case I am referring to was indeed by a German newspaper. So if you have something, which you would not like to be known just in time, just mail to the press alias. Or while you're sitting here, tomorrow at 1600, we have a BoF session. You can easily remember the date. It's tomorrow in parallel to the multi-arc session. But on the other hand, who wants to see what multi-arc is? So just remember, we have an IRC channel. We have a public list. We have a private email alias that you can contact us. So, but what are we doing, actually? Well, one thing is that we have an official Debian account on Identica. Just a small question. Who in this audience knows what Identica is? Thank you, you should put your hand up. OK, who who hasn't raised his hand wants to know what Identica is? OK, who who just raised his hand knows what Twitter is? OK, so I can't say that Identica is a better Twitter. OK, Identica is just some kind of platform where people, institutions, organizations can communicate with a whole lot of people in short messages. For example, they can tell everyone we just released or we are about to introduce multi-arc to tell everyone in an instance that you can participate in this conference by using a specific URL on the web site on the web site. So it's very easy to communicate with other people. Let's give it a chance. We are on Identica. And what we published on Identica is also synchronized on various, well, proprietary web services. I also mentioned Twitter. I think it's also synchronized to the unofficial Facebook account of Debian. Now Raphael went away. Well, I think it is. Oh, it is. OK, it's a list of people who can write to that. Identica account, it's Zeg, it's Raphael, it's Francesca, it's Maike, who is actually preparing her on talk right now. And it's me. And, well, we'll get to the topic how to propose dance later. The other thing is the Debian project news. The Debian project news are more or less regular newsletters. We try to send it out bi-weekly. If you look at your inbox, you will probably notice that we just sent out one today. It's a previous, I think, exactly one month ago. So we sometimes miss our own deadline. And that's a sure sign that that's something you can help very easily. Just for completeness, our newsletter is available in various formats. For example, as an email sent to an mailing list, it's also available on a simple website. There's an RSS feed for that. And if we don't forget it, we also announce that on Identica. And, of course, it's also translated in various languages. For example, into French and into Italian. We have a wiki page about that with more details about that. Well, I can show you a little bit more about that later. And there are press announcements. Well, there are press announcements, so they should inform journalists and our users about important changes when we release, when we change our fingerprints on the FTP master servers, when we are available on important fares, exhibitions. When DebConf is about to start, when the call for papers for DebConf starts, all the things. Well, they're just sent when things are happening, so there's no regular schedule. They're also published in different media. And then to one of two lists. For historic reasons, we have two mailing lists. A news mailing list and an announce mailing list. Back then, the idea was that some people would only like to know about the most important changes, new releases, basically. And some people would like to also know about what's going on in the community. We are a newsletter. So back then we separated those two lists. Today we more or less decide by the importance of the announcement should it be sent to Debian News or to the announce mailing list. It's more or less a rule of thumb and, well, or gut feeling, if you like. Where to send. Of course, they are also translated. And we usually draft them in the publicity team's subversion repository. That's why journals can pick them up. So when to prevent that, sometimes we have embargoed announcements, which are put into the version repository quite late, just more or less so that translators can pick them up or try to, and release on a specific date. But, on the other hand, sometimes we leak announcement previously to a hand of journalists so they can prepare their own texts, ask residents kind of that. We try that on a best effort basis. In the past, we often did not a very good job with that, but I think we are getting better in working cooperatively with some journalists. And, well, there's also a wiki page about that. So other work we are doing, we are acting as contact point for journalists when they have specific questions. And, well, we kind of act as a contact point for nearly everyone else. Many mails we receive at the press, at Debian org, alias, are just people who didn't find the right point of contact. So a lot of work we do is just point them to the correct mailing lists, web pages, and, well, connecting people, so to speak. And what we try to do is also to, well, network with other journalists to keep them informed that Debian is still alive, that we are doing great things, that we are about to release in a couple of months, that it's not a joke, that it will actually happen, all those kind of things that usually happens in, well, more or less personal contacts at exhibitions and fairs. Yeah, as I said, I'm pretty sure I missed some things. For example, the meetings Francesca organizes, or all the nice organization like Valacio does with his artwork and with his celebrations for Debian's birthday. You might remember last year on the 17th birthday is a Zeng's Debian webpage, which, well, is kind of a publicity thing, which is kind of, well, other work we are doing. Or some people who joins the publicity team does. So, how can you help us? It's the most important point. How can you propose a dent for a tweet or an activity update on Facebook? Well, that's very easy. You join the publicity channel, you write dent, colon, and your actual text. Try to have it not longer than 130 characters. Wait a little bit for feedback and someone to actually acknowledge it. Our current policy is that if one or two people have acknowledged it, it is sent out. Someone of the people who have write-assessed, don't worry about that. And, well, that's it. You can propose any dent. For example, Ice Weasel 5, uploaded to Debian Unstable, Linux Kernel 3, uploaded to Debian Unstable. Debian will be present at a conference in Guernalupur, whatever. If it has something to do with Debian, we can dent about it. If it's a nice discussion on a mailing list where some feedback from our users might be needed, we can dent about it. Just tell us. So that's quite easy. How do you help with the Debian project news? Well, that's also not very complicated. There are four major tasks which need to be done. Someone needs to propose an article or a topic for an article. Someone needs to write it. It has to be reviewed. As you might have noticed by now, many members of the publicity team are not native English speakers. At least so I've been told. Thanks. So we have a couple of native speakers just as a hobby. We review the text. We write, be it in Italian-style English, be it in French-style English, or be it in Girmish. So it needs to be reviewed. And of course, it needs to be translated. Not everyone speaks English. So the nice thing is that the Debian project news are just drafted in our subversion repository before they are actually added to the website. And every Debian developer has already write access to this repository. So hands up, who is the Debian developer in this room? Okay. In theory, every one of you, thank you, a Debian developer too. So in theory, every one of you can already contribute to the Debian project news. Even if you are not aware of it. Everyone who is not a Debian developer needs to join a project on alias, our collaboration platform within Debian. It's usually not a big problem. You just request access on the website.  And no big fuss about it. We also have a small template, so you actually can't do anything wrong by contributing. You just need to lead a little bit of knowledge about HTML, opening and paragraph, closing and paragraph, maybe how to create a link, and that's it. And even if you do something wrong, you are not very familiar with HTML. Don't worry, it's in its subversion. If you do something wrong, we can either fix it or just revert it, revert it or similar cells. It just works. And if you even don't like to contribute directly, as I said, we have a mailing list. Just mail us. As a matter of fact, there are a whole lot of things happening in the Debian universe, and we just don't notice it.  We can't monitor everything. So if you notice something which might be worse to be mentioned in the Debian project news, some institution moving to Debian or a nice product based on Debian being released right now or something like that, edit or at least mail us. So then we have the announcements. As I said, Debian is doing great stuff. Just ask Zach. But other people often don't notice it. I mean, we are the biggest distribution which is there. We have ports to all kinds of architectures, to different kernels. We have user interfaces. Other distributions dream of. We have all those nice ideas like removing dependency packages. If you actually remove the leave package, all that kind of stuff which Debian invented but nobody in the outside noticed. So contact us well in advance if you're going to announce something. If you reached an important milestone or if you implemented a cool feature, please contact us. Ideally contact us before you blog about that in your own, in your private blog. Even if it is also synced on Planet Debian or something like that. Please contact us. We might help you to find a better phrase formulation for something like that. We have review teams. We have translators. We can help you get some stuff known. We just need to know it in advance. It doesn't help us if you send us an email saying, well, I just logged about systems that feature I thought you might know. If you do that, by the time the information reaches us, everybody actually knows it. Well said, we can help you draft announcements, review them, translate them, getting your things known. So what are the open issues or problems we are facing? Well, Debian is an open community. All our mailing lists are public. Everything we do is done in the public. Everything we blog is done in public. So people outside of Debian face a problem that there is no distinction between internal communication, which is more about telling other developers about it, and external communication, which is actually written and targeting other people. For example, during the Lenny release cycle, I think it was, one Debian developer blocked on PlanetDebian.org that he doesn't think that the deadline, as it's a targeted release date, can be reached. He actually showed a nice graph showing the release critical bugs, draw a line, and then estimated that, I think it was Lenny, will be released about half a year later than expected. That was shown on PlanetDebian and was, of course, picked up by a lot of journalists, because they thought, well, it's on PlanetDebian. It is written by a Debian developer, or why would it else be on PlanetDebian? So he must know what he is writing about. While, in fact, he was just referring to the fact that he thinks we need to fix release critical bugs faster, the media thought, well, Debian is getting delayed again. It was not easy to ask journalists to, well, kind of reformulate the articles. But it was, well, from our point of view, from the publicity team's view, it was a disaster. An understandable disaster. Well, so if you write something on a mailing list, if you plug something, please keep in mind that whatever you write might also be read by a journalist. And think what the journalist will take from that. So, well, the open issues are not really sorted. The next issue is that the press team can trigger a partial rebuild of the website, but only in English. So if we add an announcement, it will only appear in English. And the translations, many thanks for them, will appear later with the next regular website rebuild. I know the web team is aware of the issue and would like to fix it, but it just needs someone with pearl knowledge, with make knowledge, with VML knowledge to actually do the thing. So another point is that there's no easy way for us to, well, know about major version updates. You know, if a Linux kernel 3.0 is uploaded to unstable or available in testing, it would be nice to mention it in the project news or maybe even dent about it. But there are a lot of important packages. And it's often difficult to find out, well, if it is worse to be mentioned, because it's a huge amount of data. So I'm speaking about upgraded packages, not about new packages. For example, if OpenOffice, sorry, if LibreOffice is updated from 3.3 to 3.4, it might be noteworthy, but we have no means to find that out. Another point is that the RSS feed for the Debian project news is, well, we don't have a feed showing the historic releases or the past releases. We just have one feed which contains one issue. It's not very suitable for many needs to be included automatically on Identica, for example, something like that. Something we might get fixed when Sobel is finished playing with his handy that we have two mailing lists and the moderation of these mailing lists works by sharing a password. This doesn't really scale. We are trying to get the moderation based on GBG keys. If you might notice that about six months ago there was an announcement and soon after our announcement there was an unsubscribed message on the mailing list. Some people giggle, they remember. That was the first attempt to test the GBG-based moderation of the list. So we are working on that. And I mentioned there are two mailing lists, a news mailing list and an announce mailing list and some users are not aware of that. Only subscribe to one and wondering why they don't... I knew one person, a colleague who was subscribed to the news mailing list and was surprised by the fact that when Squeeze was released because the Squeeze release was only mentioned on the announce mailing list. I have no real idea how to fix this problem if it is an actual problem. I don't think it's suitable to just merge them, something like that, or to actually tell everyone that there are two mailing lists. I have no idea how to do that. Another issue is similar to blogging. Sometimes stuff gets sent to the DB and devil announce mailing list which would actually be nice to be a proper announcement. I think two years ago during a DEP conf we had the idea that it would be nice if there was some kind of delayed moderation of the mailing list so that if you send a mail to the DB and devil announce mailing list, first the press team or the publicity team gets notified and may say, oh, well, that's okay. Just let that mail through. Or, well, may delay the delivery of that mail to get in contact with the sender. It is a nice idea, but, well, it needs someone to implement it. First step to solve that problem, better cooperation with the developers, with the community. As you are here, you're obviously interested in cooperating with us. Maybe we can work better, find a way to work better with you in the future. So if there are any ideas what the publicity team can do to be more open, more inviting for current reviewers, for developers, I'm here, just tell me. One other important point is the Debian project, the press team, the publicity team, can currently, well, release press announcement. And that's about it. If there's something happening where we would like to officially comment on it, there currently no means to do that. For example, a couple of months ago, I think there was a great fuss in the German media about, oh, what's the English word? A cease and desist letter, as I called it? Thanks. Well, it was mostly a German thing, I think. But it caused a great fuss in the media because someone got such a kind of lawyer letter because he was distributing Debian. We felt that it was needed to comment on that, to tell the people, well, yes, there is this letter, but actually, to the best of our knowledge, there's no problem with distributing Debian. We felt that there's a need to calm the community down a little bit. But the press announcement was, well, the German phrase is, mit Kanun auf Spazenschießen. Well, it was just overkill for that kind of thing. But we didn't have no other means, so we released the press announcement. There are other examples where it would be useful for the press team to comment on something without telling all journalists. And I love to tell you that the solution is inside. I rumor has it that soon we will have something called Block Debian Arc. That's for you. Block Debian Arc is currently in development. So there are some technical issues which still needs to be solved. We need to come up with a policy, what content may be published there. The basic idea is to have a platform where all developers can propose to, well, write some text, and, well, a few moderators who can say, well, that's okay, we publish that. A little bit similar to the identity casting. People propose it, others moderate it and publish it. That would be very cool for the scenario I just described, to have some way to write an official comment. I mean, even if I, as official Debian press officer, write something in my private block, it is still in my private block. It's nothing which is an official point of view from Debian. So Block Debian Arc, when it's available, will fill that need. So that are some of the open issues I remembered. I'm sure there are more. I have a small collection of links which are useful for Debian computer contributors. Our mailing list, the wiki page describing our team, the wiki page describing how to contribute to the Debian project news, and the URL of our subversion repository, which, as said, I repeated again, is open for every Debian developer to write it. Yeah, fixed yesterday night. And, of course, for our users, some useful things, some useful links, our Identica page. Either way, if you don't know what Identica is, you can just open that URL and just look around. You don't need any client or anything like that. Just open that URL and you can see what we are doing there. And our two mailing lists. As said, please subscribe to both of them to be informed. And how to contact us again. IRC channel, mailing list, private mailing hours, or our BoF session. And with that slide, I'm finished. Thanks for your patience. Thanks for showing up. Thanks for helping us in the future. And, well, if there are any questions, if you search one, please, I didn't understand the question. Here's another one. Please repeat the question. What happened to the Debian package of the day? Was it something which was done from the publicity team? Definitely. The question was, there used to be a service called Debian package of the day, which described on a more or less daily basis a nice package. To the best of my knowledge, the service discontinued because there were not enough people proposing new packages. And while the Debian system has over 30,000 packages, no one actually uses every package available. So you just know a couple of packages you use daily. So you need more input. And, well, is there enough input, enough proposals about new packages? I surely think that service can be resurrected. Does that answer your question? Okay. My name is Andreas Titter. I have a question. In the beginning you were asking or saying, you are not really sure who is the publicity team. I had the same question for other teams, and you might remember that there are this list statistic, who is posting when to the mailing list, and we have a Google Summer of Code project, which also investigates and who is committing to the S4N and who is uploading packages and whatever. So from this statistics, we know who is member of the team by counting the commits and all the things he posted. There's even a talk on Friday, I think, here. Okay. Thanks. More than a question, it's actually stressing one of the points which Alexander made. So when you speak as a Debian developer with journalists in general, when you make a statement, when you post on your blog something, journalists and press in general really want to take your position as an official position of the Debian project. This is the case whether you like it or not. So of course we are free to post whatever we want on our blogs, but please keep in mind that some people might pick that up as an official statement for the Debian project. So even in my case, when they ask me something, I try to make a distinction when I speak on a personal basis and when I speak on the Alpha for Debian project, of course difficult, because they're always something that people say, okay, that's anyhow the voice of Debian, but they try to do that with anyone who can show some sort of strict affiliation to the Debian project. So keep on posting what you want, but please keep in mind that people might pick it up as something more official than what you want it to be. Anybody else? That's it. Hey, thanks.


And that's what we're gonna talk about. Okay, so we're gonna do that. I don't want to spend a huge amount of time on it because, but since it's such a watched video and since so many of you sent it to me, I feel like obligated. I sent a lot of people like emails and texts and saying, I don't think it's any good, but I didn't explain. So now we'll explain. And we'll start with the good stuff because we're starting at two minutes and two, 20 seconds in. We said some things that are true, which I think are interesting and right. So we're gonna do that and we're gonna talk about that. Then we're gonna go to the stats and see where I think he completely messes up. All right, here we go. So let's see. Let's make sure you guys, I think you guys will hear this. If you can't hear this, let me know. Focusing on COVID. And so one of the things I'd like to talk about is when I talk to ER physicians around the country, what's happening? Well, because COVID has become the focus, people with heart disease, people with cancer, hypertension, and various things that are critical are choosing not to come in based on fear. And I think this is true. And I think very dangerous. And I think one of the real costs of the lockdown and of the fear mongering. Now it's true that in New York, and we'll talk more about New York, it was probably good that they didn't come in because New York hospitals, at least some of them were so overrun that it was good that they stayed away. But in most hospitals in the United States, particularly where this doctor is, and Dr. Erickson, I should have introduced him, is a physician in a network of hospitals, private hospitals, clinics in California. In California, where the hospitals are not overloaded, indeed the hospitals are empty, where the hospitals where doctors have been furloughed, where nurses have been furloughed, this is a real problem. And a problem that should have been addressed early on. Early on. So what that's doing is causing the health system to focus on COVID and not focus on a myriad of other things that are critical. Because we don't have the staff there and the major component is fear. People are saying, I don't wanna go get seen by my doctor. What if I get the COVID? So there is a lot of secondary effects to COVID. I think all of that is true. All of that is what we see. Again, particularly in hospital systems that are not overloaded, where there's no problem, which is 90% of the country right now. But yes, I mean, hospitals should be functioning normally. They should be uppatient. They should be elective surgeries. They should all be, these things should be going on until you get this massive spike, like we got in New York, if you ever get that, where you then have to stop those other processes. But that's not what's happening. And this is medicine driven by fear. Policy driven by fear. And policy and medicine dictated by politicians, not by physicians. Talked about. And so we'd like to kind of look at how we responded as a nation and why we responded. Our first initial response two months ago was a little bit of fear. We decided to shut down travel to and from China. These are good ideas when you don't have any facts. We decided to keep people at home and isolate them. Even though everything we've studied about quarantine, typically you quarantine the sick. This is interesting, right?  Quarantine as in forced isolation is usually applied to the sick. And that's what North South Korea did. That's what Taiwan did. You test and you quarantine the sick. Again, the fundamental failure of the United States response to coronavirus was not testing on scale early on and not quarantine and tracking and doing the things necessary. And I'll talk a little bit more about that later on when I wanna recommend an article to you about the whole corona thing. When someone has measles, you quarantine them. We've never seen where we quarantine the healthy, where you take those without disease and without symptoms and lock them in your home. So some of these things from what we've studied from immunology and microbiology aren't really meshing with what we know as people of scientific minds that read this stuff every day. So that's kind of how we started. We don't know what's going on. We see this new virus. How should we respond? So we did that initially. And over the last couple of months we've gained a lot of data. Typically in Kern County, for instance, now from this point on, for the next, what? For the next good 10 minutes of talking over that it's all about the data. And this is where it goes completely wrong. Tested, 5,213 people and we have 340 positive COVID cases. Well, that's 6.5% of the population, which would indicate- It's not 6.5% of the population and this is the key. They tested 5,213 people. They had 340 something positive. Now, is that sample a random sample? No, that is people who came to the clinic because they had symptoms. They felt sick. They are by a sample. And of those that were tested who came to the clinic with symptoms, 6.5% tested positive. That's not a population. That's a biased sample. A sample that you would think was preconditioned to have a high rate of positives because they were feeling something. They weren't feeling well. Indeed, at least until recently, the CDC said don't test people without symptoms. We don't have enough tests. And California explicitly said don't test people without symptoms. We don't have enough tests. So the people that are being tested are people who have symptoms and therefore you cannot talk about the population of people who have symptoms and who go to get tested, which is another condition, 6.5% of them in his sample tested positive. It's a widespread viral infection similar to flu. Flu has far greater than 6.5%. So he's already injecting this flu stuff where there's no basis to do that. There's no statistical based on his numbers, basis to do it yet. We think it's kind of ubiquitous throughout California. We're gonna go over those numbers a little bit to kind of help you see how widespread COVID is and see how we should be responding to it based on its prevalence throughout society or the existence of the cases that we already know about. But they don't know how many cases are throughout society. All they know is the cases among those who are tested and you'll see again and again and again how this one fallacy, one fallacy and it's a fallacy in statistics. You cannot take a non-random sample and then extrapolate to society. I mean, this is like statistics 101 and it's very difficult to construct a random sample that is indeed reflective of society to make those extrapolations no statistician. I mean, a statistician could construct such an experiment and even when they do, it's very, very, very difficult. But this guy, this doctor just throws out the numbers and then well, this is the percentage in the population. Watch what he does with California. So if you look at California, these numbers are from yesterday, we have 33,865 COVID cases out of a total of 280,900 total tested. That's 12% of Californians were positive for COVID. Now note, every one of the 280,900 who went to get tested probably likely had a pre-existing condition. That had symptoms, not a pre-existing condition. They were a bias sample. They want a random sample where we tested randomly in the population, 280,000 people and 33,000 tested positive. No, this is a bias sample. So what he's doing now, he's gonna say, watch what he does with this. So we don't, the initial, as you guys know, the initial models were woefully inaccurate. They predicted millions of cases of death. Not of prevalence or incidents, but death. That is not materializing. What is materializing in the state of California is 12% positives. Well, if we have 39.5 million people, if we just take a basic calculation and extrapolate that out, that equates to about 4.7 million cases throughout the state of California. You can't do that. You cannot do that. He just said of all of Californians, 12% of all of Californians have it. Now, it might turn out that they do, not based on this. Not based on this, sorry. And it's sad because again, I think the motivation to argue against lockdowns and everything is a good motivation, but this is amateur hour. And he later says things that I would never go to this guy as a doctor. I wouldn't. Based on just his attitude and based on how he's, if he can't do this kind of, if he can't extrapolate here, I don't want to even think about what kind of treatment he provides me. I want to skip ahead a little bit to New York because the fact is, and however you look at the numbers in California, they're low, they're very, very low. And I'll give you a few more seconds of this and then we'll skip to New York. California, there's no justification in a disposed place like California to have these kind of lockdowns. It is literally insane in my view to lock people down all over the California where the prevalence of this is so low, even if you don't buy his extrapolation. But that is not true in New York. Which means this thing is widespread. That's the good news. We've seen 1,227 deaths in the state of California with a possible incidence or prevalence of 4.7 million. So he divides the number of deaths by 4.7 million, but he has no basis for the 4.7 million. He just pulled out of air. This is not true. This is just, I don't know if he's doing it on purpose or not, but this is so amateur that it is shocking, truly shocking. And the fact that five million people view this and the fact that it gets so many positive ratings and that people don't get this is a little scary to me. 0.03 chance of dying from COVID-19 in the state of California. That is called disinformation, misinformation. Misinformation. 0.03 chance of dying from COVID-19 in the state of California. Is that, does that necessitate sheltering in place? Of course not, but neither does double that, triple that. Does that necessitate shutting down medical systems? That's not the point. Does that necessitate people being out of work? So that's California. And that's, I also wanted to mention that 96% of people in California who get COVID recover. What does that mean, 96% recover? If that were the case, 4% don't recover, 4% die. So he's, even the way he's using language is just not being accurate. I think he says 96% recover without hospitalization, but 96% recover. So 4% die, that can't be right. He just said 0.03. So it's so sloppy. No significant, no significant continuing medical problems. So that's, those are important statistics for the state of California. Two months ago, we didn't know this. So is it true that over 4% of the people who get COVID have significant ongoing problems? Cause I'd like to know that, that is a huge, that's a big number. If you have a probability of 4% if you get COVID to have significant problems into the future, that's not the flu, the flu you get and you're over. But if this actually, that's what he's implying. It's not what he means to imply, but that's what he's implying. Again, you've got to listen to what people actually say and think about what it actually means. Right now, because we've, we're sharing our own data. This isn't data filtered. But it's not his own data. The data he gave us was California data on 12%, that's, that is filtered by the state of California. His own data was 5,213 versus 340 positives, which is only 6.5. So he used the number that is double his own data. And yet he keeps going back and saying, this is our own data. We're, we don't have a dog in this fight. We're not politicians. This is real data.  Through someone. This is our own data. We found 6.5% and then California has found 12%. So the more you test, the more positives you get. The, no, the more you test, it's not true. The more, the greater the number of positives you get, but the actual percentage actually goes down. Actually goes down the more you test. You know, we'll get to in California, in New York in a minute, we'll get to that. I'll give you the numbers there. But he's just, none of this is right. Prevalence number goes up and the death rate stays the same. So it gets smaller and smaller and smaller. That is true. And as we move through this data, what I want you to see is millions of cases, small amount of death. Millions of cases, small amount of death. And you will see that in every state. And if we, and since we were talking about following the science, we're going to follow the statistics and follow the science. So I want to look at New York state. Let's do New York. They've been in the news a lot, right? And their numbers are critical. Let's go over their numbers. Cases of COVID as of yesterday, 256,272 cases in New York state, not New York City, New York, the entire state. They did a total of 649,325 tests. That's 39% of New Yorkers. See, yeah, see, here's an example. That is 39% testing positive, right? Now a few days have passed since he did this video and the number of test has increased in New York. And the rate of testing positive, even though the number of tests has grown, the rate of testing positive is actually shrunk. It's not 35%. And my guess is the more you test, the rate of testing positive is shrink because you're expanding the universe probably to beyond people with symptoms. So what he says earlier, where the more you test, the greater the percentage, it's just not true. Tested positive for COVID-19. That's their ratios. This is published data online. You can all look it up. 39% of people were tested. 39% of people were tested. Now this guy is trying to correct him. He's trying to give him an out. And Dr. Erickson doesn't take that out because he's convinced he's right. Listen. Right. There's 20 million people there who would be close to, you know, four million. Which is likely, they likely have 7.5 million cases in New York. No, it's not. Yeah. 35% of every New Yorker, it's every New Yorker who's been tested. Right. So we extrapolate data. Yeah, yeah, yeah. We extrapolate data. We test people. And then we extrapolate for the entire community based on the numbers. Oh my God. I mean, this guy would fail statistics class. Or just a, what do you call it? A reasoning class. A critical reasoning class. He would fail. That is just not true. You can't do that extrapolation. You cannot do it. And all of us need to become much, much better critical thinkers. If we're gonna stand up to these politicians and these experts and these idiots who are presenting us with data, who are convinced they can run our lives, we better be much better thinkers if we're gonna challenge this. And this is not good thinking. The initial models were so... This does not include antibody tests. Anybody tests are completely different. And there's a whole problem with antibody tests, which is false positives are very high in antibody tests. But this is not including antibody tests. This is, and you can look the numbers up because you can look it up on the websites that this is just positive negative. Right now, do you have it? Not anybody. You're right. But in those additional models, a lot of them are based off if we didn't know social distancing. Is that correct? So is it really a fair to say, obviously they're not as bad as they were because those were based on alternative... I'm just gonna skip forward a little bit. And they have a 92% recovery rate. If you are indeed... Again, what is 92% of what? Let me just find the right spot here. 1.5 million cases? We don't know. We will never test the entire state. So we extrapolate out. We use the data we have because it's the most accurate we have versus a predictive model that have been nowhere in the ballpark of accurate. So how many deaths do they have? 19,410 out of 19 million people, which is a 0.1% chance of dying from COVID in the state of New York. By the way, that is just not true. Okay. You divide 20,000, which is 19,000 something, which is what he said, divided by 7.5 million, you get 0.267. I mean 0.26, something like that, right? He just said that you get 0.1. No, I think he said 0.13. No, it's exact double that. It's 0.267. Now you shouldn't be divided by 7.5 because 7.5 is out of nowhere, but you can't even do the math. That's a calculator. I just pulled out a calculation. Now that doesn't look right. Let me divide 20 by 7.5, 20,000 by 7.5 million, and it comes out as 0.26%, now 0.2% is still low, but 0.2% is, according to Dr. Erickson, the mortality from the flu is 0.13. 0.26 is double mortality of the flu. Now that's not hysteria, but it's double. It's not the flu. It's double the flu. Now, the number of New Yorkers who have this is not 7.5. The estimates that have been made based on antibody tests are that about between three to four million New Yorkers, and even that, we don't know exactly, right? But let's say three to four million New Yorkers, that's what the latest tests have shown, have it. And if that's the case and 20,000 have died, then 20,000 divided by three to four million is something around 0.5.6%. Now it's six times more than the flu. Now, that's real. Six times more than the flu is real. Paul asked why you can't do the extrapolation. I said it, I guess you came in late, because you can extrapolate from a bias sample to a general population. Again, stat 101. To extrapolate, the sample has to be a random sample, or a sample that represents the population. But here we know the sample's not random. We know it doesn't represent the population, because the only people that are being tested are people who have symptoms. And you expect that among people who have symptoms, the percentage of people who test positive is gonna be significantly higher than among people who don't have symptoms. It's a bias sample. It's bias because of the symptoms. You can't extrapolate from a bias sample. It's very, I'll say this one more time, for those of you who came in late, it's very, very difficult to construct a sample from which you can extrapolate to a general population. It's a science to do that. And it's the seriological tests, the antibody tests, that's what they're trying to do. And it's very difficult to, many of them are failing. What they're trying to do is find a sample out there of a few hundred people that they can test. And from that test, because the sample represents different ages and different, let's say socioeconomic people and different people in different geographies and different densities and different health statuses, maybe, then you find several hundreds of those and you test them and you control statistically, then you can extrapolate to a population. But that takes huge amounts of work to do that. You can't just assume that everybody you test because they come to you to be tested. Particularly if the condition for testing is that you have a symptom, you can't assume that that is a sample. It's not, it's not representative and you cannot extrapolate. And again, this is not, this is not science fiction. This is at best, at most, one of two things. Stat 101, a critical thinking 101. Now let me see, what more do I wanna talk about here? I wanna move it a little forward to when he talks about the flu because I think there's some interesting stuff when he talks about the flu. Let's see if I can find it. Flu.  And the deaths in the United States were 43,545, similar to the flu of 2017, 2018. We had, we always have between. By the way, we're really early in this coronavirus thing. There's over 50,000 dead and we're early. I mean, we'll be on maybe the peak but there might be other peaks. And some parts of the country have experienced it. Some parts have not yet. And it's contagious, it's probably gonna spread. So we're only at 50, with 50 something thousand dead. Why are we assuming it's over? Why is that the number being used? As if it's done. I mean, I hope it's done. That would be great. Nobody die tomorrow. But this is likely to be over 60,000. That's an easy projection for me to make right now. Probably over 60,000 in the next week or so. It's likely to reach 80,000, which is what some doctors have been saying all along. And it could be much more than that if it comes back in the fall or if it doesn't go away in the summer. So why are we ready to take the numbers as they are right now and come to conclusions about this? Right? The only conclusions we come is other people sick right now, this is the number who are dying. But we don't know how many people are sick right now because we haven't run enough tests and we haven't done the kind of random samples that you would have to do in order to figure this out. It's, this is massive misinformation. Massive misinformation. You know, again, a cause I'm not unsympathetic to which is opening up the economy, opening up our lives. But this discredits the opening up our lives attempt because if you do it with bad information and bad thinking and bad extrapolation, then you're discrediting the cause. The cause is a cause of freedom. The cause is the cause of having a rational attitude towards this disease. But if you're trying to do that with irrationality, I mean, it should be obvious that can't work. Five million people have watched this video. My rebuttal to this is gonna get to a couple of thousand maybe it's tragic, tragic that this is gonna be what represents. All right, let me just do this flu again a little bit. Again, the number in New York, he did the math wrong. The number of New York is more than double the flu. And that's assuming is seven and a half million people have the virus in New York, which is a number he's plucked out of thin air. I mean, he's extrapolated out of thin air, right? But there's something else he says. Seven and 60,000 deaths in the United States. Every single year, no pandemic talk, no shelter in place, no shutting down of businesses, no sending doctor's home. That's from the flu, by the way, just to clarify. Yeah. 37,000 and 60,000 flu deaths. 37,000 and 60,000. Every year per the CDC. 30. Flu. Due to flu. In the United States. It's even as low as 20,000 some year. In 2017, 2018, it was 45 to 50,000, depending on who you read. And we don't necessarily report all of our flu tests. We do thousands of flu tests every year. We don't report everyone because the flu is ubiquitous. And to that note, we have a flu vaccine. How many people even get the flu vaccine? The flu is dangerous. It kills people. So just because you have a vaccine, does it mean it's gonna be everywhere? And it doesn't mean everyone's gonna take it because we see every year that we have a vaccine. And I would say probably 50% of the public doesn't even want it. Do you think it would be relevant if you're talking about a flu vaccine to talk about the fact that the flu vaccine is not necessarily vaccinating you against the particular strain of flu that occurs that year? That flu every year is a different strain. And when they put out the vaccine, they're in a sense guessing or estimating or making their best assumptions about which strain will hit the population at that point in time. So that even if you get the vaccine, you could get the flu because you might be vaccinated against the wrong flu, the wrong virus. That is crucial information because a corona vaccine will be a vaccine targeted at the one virus. And therefore will be far more effective than a flu vaccine. And even if not everybody gets it, the vaccine, there will be far fewer. I mean, again, it's this kind of muddled thinking that would turn me off of this doctor completely, completely, right? All right, so I don't wanna keep going. I mean, he keeps going on this stuff. And again, some of the stuff he says later on is fine, but the stuff he says about Sweden, the stuff he says about Norway, none of it's right. None of it's right. He makes basic errors. He leaves information, critical information out of the equation. And it's just a discredit, a discredit to what you're trying to do. Now, all right, so that's it. That's my thing on Dr. Erickson. What we need today, what I call the new intellectual would be any man or woman who is willing to think. Meaning any man or woman who knows that man's life must be guided by reason, by the intellect, not by feelings, wishes, wins or mystic revelations. Any man or woman who values his life and who does not want to give in to today's cult of despair, cynicism and impotence and does not intend to give up the world to the dark ages and to the role of the collectivist brought. Using the super chat, and I noticed yesterday when I appealed for support for the show, many of you stepped forward and actually supported the show for the first time. So I'll do it again. Maybe we'll get some more today. If you like what you're hearing, if you appreciate what I'm doing, then I appreciate your support those of you who don't yet support the show, please take this opportunity, go to uranbrookshow.com slash support or go to subscribe, star.com uranbrookshow and make a kind of a monthly contribution to keep this going. I'm not showing the next.


So this is the talk all the parents are waiting for, hopefully this will explain why you do have to do maths to be a video programmer, hopefully. So to not cut into his talking time, please give a very warm welcome to Matthew and Maths and Video Games. Okay, thank you very much. Yeah, so I'm Matthew Scruggs, I am a PhD student at University College London where I study maths, but I'm not talking about anything to do with my research today, I'm going to give you some bits of maths applied to video games. So mostly this talk is retro arcade games, most of which you can find in the arcade here, and I'm going to do some mathematical analysis, so maybe some mathematical over analysis of these games. So first of all, we're going to look at everyone's favourite game, Pac-Man.  And when playing Pac-Man, the kind of thing you might wonder is whether it's possible to go around and eat all of the dots without having to double back on yourself in various places. And this is something we can work out, and this is related, so the question is we're trying to find out if Pac-Man can go around the maze and only go down each road exactly once and not have to kind of go down a bit and then repeat back on himself if there is a route that does that. And this is related to a very famous problem maths that many of you may have heard of called the Seven Bridges of Kernigsberg. So there's a town called Kernigsberg that had seven bridges. If I colour the map, you can see that the green is the islands, the light bits are the lake, the rivers, and the orange bits are the bridges. So the bridges were arranged like this, and the story goes that in Kernigsberg, the residents of Kernigsberg would like to go for walks and would try to go on a walk and try and cover each bridge exactly once. So maybe something like this, you go over that bridge, over that bridge, around here, there, and then the resident on that walk is then annoyed because they've missed that bridge at the top and the middle, so they've not successfully managed to go over all the bridges exactly once. And this became more and more famous, this problem, because as they tried it more and more, it became more and more clear that it was very difficult to do this. And in the 1700s, I believe, this man, Leonard Euler, came along and he explained why this was impossible. And he did it by first of all simplifying the problem. So he said that actually the shape of the islands, the shape of the bridges, the distances are kind of all irrelevant. All that matters is the islands and how many bridges are between them. So he drew dots for each of the islands, and then drew lines where each of the bridges went. So instead of having any of the geography, you don't care about that, you just know the two connections between this island and this island. And then we can ignore the map and now we are asking if you can draw the black lines on that diagram without taking your pen off the page. So we've made it a slightly different problem. And he worked out that in fact for Kernigsberg, this is impossible. And he did that by looking at a point. So if you look at, if you choose one of the islands, this island has an even number of bridges connected to it. And this means this is really great if it's an even number, because if you go onto the island, you can come off because you can pair it there just because it's an even number.   But if there's an odd number of bridges, say this one here, you're going to come onto the island again and now you're going to be stuck because there's no bridge to pair that with to come off. So if that is your last island, you're very lucky and you can stop because you've reached the end. If that's not your last island, you're going to fail because you've got stuck somewhere. And similarly, if this was the first island, you could have come off that bridge and it would have been fine. But if it's anywhere apart from the first island or the last island, an island with an odd number of bridges is going to be a big problem and make it possible. So back to Kernigsberg. There are five, three, three and three bridges coming off each island. You'll notice five and three are both odd numbers. So we have four islands with an odd number of bridges. So therefore, it's impossible to draw Kernigsberg, to walk around Kernigsberg without going over a bridge more than once because you're going to get stuck on more than two of these bridges. Okay. And now we can apply the same thing to Pac-Man. But first of all, I should update you on the story. So this is a very old story. Kernigsberg is now called Klinengrad. One of the bridges was destroyed during the war. Another one's been built. So Klinengrad now looks like this and there are the islands, there are the bridges. And it's actually now possible. So you've got this kind of graph going on. You'll see now there are two odd islands and two even islands. So if you start on one odd island, finish on a different odd island, you can do it, something like that. So now actually it is possible to walk around what used to be Klineng, what used to be Kernigsberg and visit all of the bridges exactly once. Right. Back to Pac-Man. So we want to ask the same question for Pac-Man. We want to ask, is it possible to go around the Pac-Man map only going down each route once? So again, just like we did with Kernigsberg, we replace all the positions where more than one little routes intersect with dots and draw lines between them and you get this. And the dots that I have coloured red have an odd number of bridges coming off of them. And if we don't need to count them, you can immediately see there's more than two red dots. So it's going to be impossible because you're going to get stuck on all of those red dots. So we have successfully worked out that Pac-Man is not easy. There is no way of completing Pac-Man without having to double backing yourselves. But that's not really enough information to kind of win at Pac-Man. We want to ideally win at Pac-Man. We know we're going to have to do some repeating, but now the next sensible question may be which routes do we want to repeat? And this is known as the Chinese Postman Problem. It has one of those most commonly called the Chinese Postman Problem. And this question is now, given a collection of islands and bridges or Pac-Man routes, what is the shortest route the postman has to walk so he delivers letters down every road? So which edges do I want to repeat in order to make this possible? And one way you can solve this, the way you tend to go about solving this, is you pick some of the edges to double up. So maybe you could double up that edge on the bottom and that edge spiraling up there. And you can kind of pretend that, instead of just repeating that edge down there, you just kind of make a second copy of it. And now all the islands have an even number of bridges, so now you can go around the map. But you can do this in different ways. So for this, for four islands, there are three different ways you can add these edges. So you kind of do those pair, those pair. The one at the bottom, there's a new edge going from the four at the bottom to the four at the top, which isn't actually a road for us. You'd have to go either around the side or around the other side, depending which one was shorter. So that's your few more combinations to check there. And yes, so for four islands, there are three different ways of doing this. This number increases quite quickly. So if you have six islands, you're going to have 15 different ways of matching up to check. 10 islands, you're going to get 945. For Pac-Man, there are 20 odd islands, odd nodes. So for Pac-Man, there are 654 million different ways of pairing these up that you need to check. And you need to find which of those has the shortest X traditions you need to cover, which is quite a lot. But it's enough that I left my old laptop running overnight and it told me that in order to commit Pac-Man in the shortest possible amount of distance, you should repeat the edges I've marked on that graph there, which would look something like this, which doesn't have sound. Imagine the Pac-Man sound playing. So you go around there, go down here, then we're going to repeat that one. So that's the second time going on the edge. Oh, it's okay. It's not important. Then this one repeats. We repeat this one round there. So that is the shortest route to complete Pac-Man. But you will have noticed when watching that that actually there was some choice that I could have made. So in some places, I went up the side and I repeated the edge going over there, but I could have gone over the top first and then down and repeated the other way. So in this, there's a lot of choice as to which order you do this repeating in, which is useful because it meant I just tried different ones until I found one that avoided the ghosts. But it isn't necessarily true that all of these are exactly the same length. So actually, we might be able to do slightly better than that. So if we look a little bit more about how Pac-Man moves, so let's first look if you're turning a corner. If you press the down button in that frame shown there, it takes this many frames to turn a corner. If you press the down button one frame later, it's going to take one frame more to go down. So it's important that when you're moving Pac-Man around, you press down in that frame and not that frame so that you save one frame of movement. Luckily, if you hold the down button, Pac-Man will automatically move in that frame. So holding down, holding the direction when you go around a corner is the best way to corner and Pac-Man. Okay, going straight across like that, you might think it is bleeding obvious that this is going to be the shortest way of doing it. You just go straight across. But actually, if you press down in that frame and then straight on again in that frame, Pac-Man actually jumps one frame across as he tries to turn the corner and then straightens up again. So you can cut one frame of movement out of there. So we can do slightly faster. We can cut some frames out of the video. And then you can look at other things. So here, when you've got crossroads, you've got two choices for how you could do. You could do it with two corners or two straight crosses. Oh, interestingly, for this one, if you're going straight upwards and try and do this trick, you actually take one frame less than you would take if you go straight across because Pac-Man moves slightly differently going up as going across. So if you're going up, you shouldn't do this attempt at cornering trick. So yeah, if you look at these two, then doing them both as corners, you get 50 frames. If you do them both as straight lines, even with the trick, you get 57 frames. So wherever we've got crossroads, we should try and make both of them into turns rather than going straight across at all. And similarly, we can look at positions like this. And the one on the right is the shortest one there because the one on the left, it has a double bit of extra distance where it's in the one on the right. You can turn around at the Pac-Dot before you reach the corners. You save a reasonable amount of travel there. So you should always try and do this whenever you've got positions like that. And similarly, if you've got positions like this, then that one is longer and the other two are the same length. So now we know which edges we want to repeat. We now want to find a way of repeating those edges while using these tricks to get the shortest route possible. And there's a few choices and this is one way of doing this. So here I've got, I'm repeating the same edges before, but I'm using these choices for turning corners to make sure it is actually the shortest amount possible. And here is me attempting that. I'm going to go back and show that again. When I go past the little first upwards, watch very closely because for two frames Pac-Man is facing upwards and he jumps back down again. I did have to use tool assisting to get this one working because I cannot react that quickly. So you see kind of like it lurches upwards in the back again. He's just saved a frame. And again here, saving a frame. And again. Yeah. So there's a problem with what I've done there is I did the math. I worked out the shortest routes. There's a few different ways you could do it. A few different choices you have for the routes. But in all of them, the ghosts will get you. So it's not possible to complete Pac-Man in the shortest distance possible. We now have to ask a different question, what is the shortest route possible that also avoids all the ghosts? And that is something I've not answered yet. Eventually I'm going to sit down for a very, very long weekend and play all of the possibilities like this. And then all the possibilities is one frame longer until one of the works and I will find the shortest. But I've not done that yet. So we're going to leave Pac-Man behind, at least trying to find the shortest route in Pac-Man behind. But there's one other thing that's interesting in Pac-Man. When you go off the left or the right of the screen, you come back on the other side in Pac-Man.  And this is a little bit weird because if I walk out of that side of the tent, I'm not going to come straight through that door unless I'm very magic. So Pac-Man is living in a kind of weird space. But actually if you think about it a little bit, you can kind of understand what Pac-Man is actually doing here. So I'm going to mark them with arrows now to kind of show that those two sides match up. So we see that when Pac-Man goes off there kind of facing upwards, if maybe his head is facing upwards, he comes back on the other side facing the same direction. And you can imagine picking up the Pac-Man map and kind of bending it round so that these two arrows meet up. And you can imagine the kind of shape you might get if you bend this around so the arrows meet. Hopefully you're imagining something a bit like this. I'm going to leave this for a second because this took ages. Yes, so actually Pac-Man lives on a cylinder and it's not weird. So he's not walking out of the tent and coming back on the other side. He's just kind of like going around on a tube and coming back on the other side. And this is the shape of Pac-Man's world. He lives on a cylinder. And this is quite common in lots of kind of old retro games. Bubble bubbles, another one where it happens.  You can also bounce bubbles upwards and come back on the bottom. And this is the same but kind of rotated. If you imagine bending it around again, bubble bubble is on a cylinder, which won't help you play any better, but it's a useful thing to know. Right, so that was when we took a rectangle and we said if Pac-Man goes off the other side, he comes back on the other side facing the same direction. But there are other things we could do. We could say if Pac-Man goes off the right, he comes back on the left but he's now upside down. So we could flip on these arrows over and say, what if we did that? And now you can imagine, so imagine that that rectangle floats out of the board and it's kind of, it's now made of kind of flexible material. I'd like you to imagine taking that flexible material and trying to bend it around so that those two arrows match up on the opposing sides and try and visualize what you get. I'm going to show you shortly, but I want everyone to kind of imagine what kind of thing you're expecting to see first. It would look something like that. So it's like a cylinder but it's got a twist to it. This is called a mobius strip and they're really quite fun. And if you come to the math video later, I'm sure we can show you lots of fun tricks you can do with mobius strips. But as far as going off one side and coming on the other side goes, this is about as much as we can talk about, but there is more we can go to if we think about the game asteroids.  So now it's like Pac-Man and the left right is making a cylinder but you've also got an extra rule going around the top. So we can draw this something like this. So we've got if you go on one side you come on the other side facing the same way. If you go off the top you come on the bottom facing the same way. And again it seems like a 2D game but you can imagine now taking this off making it into bending material and bending it around to see what shape you get. Again I'd like you to try and visualize that first if you can imagine what's going to happen. So imagine taking that bending around so that the red arrows touch then taking whatever you're going to get and trying to bend it around so the blue arrows touch. Hopefully you're visualizing something like this.   You're welcome to call it donut after the talk. So actually asteroids is a three-dimensional game not two-dimensional game because the asteroids are all moving on the surface of this torus. But we could play with this rule. Again just like we do with Pac-Man we flip this around a bit. We could play with this a bit. So how about we take the red arrow on the right and we flip it upside down and for some reason the blue one swapped but it doesn't matter they're still facing the same way. So now if we go off the top we come on the bottom and now if we go off the right we come back on the left but we're going to be upside down. So a game on this might look something like this. So you fly off the top you come back on the bottom but now if you fly off the right you come back upside down on the other side and it's really confusing and hard to play. Let's watch me fly around a little bit. Yeah it's when you go off the side and just appear at the bottom you just always hit asteroids because you cannot tell where you're going because it's really odd. Okay so again we can think of this game and try and work out what kind of surface the asteroids are moving on. So again I'm going to give you some time to think about to see if you can imagine what's going to happen. So you want to take this and now you want to bend this round and see what kind of shape it's going to make if you bend this so that the arrows match up. And maybe it's easier to think about the blue ones first because if you do those blue ones we should know what we're going to get by now and then think how are you going to do the red ones and maybe you can imagine something as fast as that. So you do the blue ones and you get a nice cylinder then you try and bend it round but now we have a problem we can get near the torus and we've got the arrows but arrows are facing two opposite directions and you can think you can twist these around you can kind of bend them about but whatever you do you can't really work out how to get these to match up and actually in three dimensions you can't but you could do this in four dimensions. A drawing of it looks something like this or like a kind of 3d picture is a bit like this so it's you've got your kind of cylinder and then you bend it around and it kind of has to go through itself and then come out from itself kind of inside out. So this is a four dimensional shape called a Klein bottle and that is what the game of asteroids with this rule is going to be played on. Okay, those of you that are ahead of me will have noticed you could do one more rule for your game of asteroids. How about if we swap the top and the bottom so now the left and the right upside down and the top and the bottom are also upside down.  Okay and this one is even harder to visualize what's going on so I'm going to kind of show you what this surface would look like.  What you get is often drawn a bit like this and in that picture I can't tell what an earth that's meant to be but the best way to visualize what it actually looks like is if you take this here so this is a surface which along the line kind of cuts through itself so it's kind of a weird spirally surface that has a kind of self-interception point and then imagine stretching this out a bit and bending it over and then kind of closing that shut so that the two parts touch so it's that surface you bend it round and then close it off like that and this is if you sit down and think about it later you can work out that this would then have the same kind of behavior as the surface I showed you and it's another four-dimensional shape this is called the real protective plane I almost forgot the name of the shape it's a real protective plane and it has the behavior like that so as far as rectangles go we're kind of done with asteroids for now um but you could go further and you could do some games on hexagons um so for example this is the kind of thing you might draw and here you could kind of bend this around and match up the arrows and see what you get I'm not going to get to imagine this but if you look at the green and the yellow you will see it looks a bit like a tourist just on that half and the top half looks a bit like a tourist and if you bend this one round and stretch out of it you actually get a double tourist so it's kind of a figure of eight with two holes and two donuts glued together um okay um so now a few more things about asteroids before we move on so some of you might have noticed the problem when we bent asteroids into a tourist there was actually a problem with what we did um so you all know when you play asteroids all of those lines the same length and all of those lines are also the same length um it takes the same amount of time fly over the top of the screen as it does over the bottom of the screen but when we bent it into a tourist that circle around the middle is a lot smaller than the circle around the outside um so actually this isn't quite an accurate representation of asteroids and that's because when we were doing it we're doing lots of stretching um so it is actually possible to do this without any stretching um to do that I'd like you to imagine that that is kind of like one around the out one across the rectangle and then it's moving around the other one so you can imagine that you're taking your like one orbit around the rectangle and you're kind of moving it around like that so it's like you've got kind of a cylinder but it's doing this kind of movement and if we trace that out this is the kind of shape that asteroids actually has to live on because now if you follow um around each circle you've got the same distance but also if you follow a point on the circle as it goes round um all of those are following the same amount of distance because it's not rotating as it goes um but at the bottom there the kind of the surface shape cuts back through itself um so this again isn't possible in three dimensions but it is possible you can do this in four dimensions and four dimensions you'd have like some extra space there to kind of bend the tours around itself and this would work so I'm going to claim to you now that actually um asteroids is a four dimensional game um so when you go to the arcade later play asteroids you're actually playing a game in four dimensions right one more game that this happens in um is fun and fantasy um if you remember the PlayStation Final Fantasy games they have the same kind of thing where you go off the top you come on the bottom um you go off the right you come on the left um and again this means that if you bend it round um you will get um again the same kind of animation again you bend it round and you get a donut shape um so again in Final Fantasy when you have this map being like this you would expect the world to look like a donut um unfortunately no one told the game developers this and if you play the game they show you a lovely picture of a sphere there which is definitely not what you're living on um but to finish I kind of I thought I ought to explain to you what's wrong with saying that's a sphere um so I should show you what goes wrong what actually happens when you do this bit so this is the world map you're probably most used to um and I'm sure you know if you fly off that side you come back on this side but unlike asteroids if you fly off there you don't come back on the top you don't kind of go to the south pole and suddenly appear at the north pole um you kind of maybe come along somewhere like that um but it's a little bit more complicated like than that so if we look at asteroids on this map this is actually what we look like if you fly around on a sphere on the map so it all looks kind of normal there but as soon as I start flying upwards you see I do some kind of weird curving and bending and you go to the top and you become huge and move really quickly and this is all because um the earth is a sphere and the map is a flat surface and because the sphere is curved and the map is not curved there's no way of perfectly representing what the sphere would look like um so however you draw a map um ideally you draw a map where angles and the size of things on the map are the same on both the sphere and on the surface um but it's impossible to do this perfectly um so the one I've shown you is called the macata projection this is the most common projection um and this um so because you can't do a map perfectly you have to choose some things you'd like to keep from the map um and some things you're going to have to lose and the macata projection was chosen so that if you are on a boat and you pick a bearing from north and sail straight along that that will be a straight line on the map um so that's actually not straight on the sphere because as you go downwards you should actually curve in a straight line but if you're on a boat being rocked about it seems straight to you so if you follow a bearing it looks like a straight line on the map and that means this map is very useful for navigation but it gets things very very wrong by the north and south poles um particularly the arc dip becomes huge like your ship becomes huge as you go down so an alternative proposed to fix that is the gull peters projection which is a different way of drawing a map um and in this one um the angles are all completely messed up no one has any idea what any what angle is anywhere but the areas of everything is the same so in this one um the relative size of the uk to australia is actually correct Antarctica looks a lot smaller than the map you're used to um so you can fly mass asteroids around this map the gift takes a while to load um and again you can see you can see this time when you go towards the top you don't get any bigger but you kind of get weird and crushed and start moving really fast and really odd directions um so I find this one really hard to play because if you go actually straight upwards you just appear somewhere miles away because you get crushed really flat and then appear somewhere else um yeah so that is the gull peter projection um there are lots of other ways of doing um 3d a sphere onto a flat surface I'm going to show you one more than I will finish um the last one I'm going to show you is the craig projection sometimes called the mecca projection um so this is a map that's centered on mecca um and if you go anywhere in the world say you go to leadbury in the united kingdom um and you put this map down and you measure the from north where you are the angle round to the red dot there that will tell you the angle like the bearing from where you are to where mecca is so if you want to say pray towards mecca this map can show you everywhere in the world which direction you should pray in um so kind of if you take leadbury and draw the arrow there that is the angle on the map shows you the angle in real life that you should face in order to pray in the right direction um although this representation is a bit of a lie you might notice there's no Antarctica um in fact a whole half of the sphere is kind of hidden away actually um would have to go on top of what's currently there um which is what I did when I made this in asteroids um so you can watch me fly around on the surface for a little bit here so you can see if you fire towards the cross in the middle which is where the center of this map is um the the the bolts actually go through the cross um and if you fly around away from it you bend all over the place um and these the bits on the side are kind of infinitely tall as well so you just get lost sometimes um it's not really useful for navigation but for finding the angles to certain places it's really useful um yeah I dial out in this one um right so that is the last bit I have to show you um just a couple more things first of all I've so I call the game I've just shown you masteroids obviously um if you want to have a go at this if you go on that web page on my website you can play all those levels of masteroids I've shown you their all gifts taken from there um and hopefully this evening it may also be coming to the badge I'm going to have a go at getting that across the badge so tomorrow I'm not getting masteroids on the badge um but otherwise that is the end of what I've got to say um so thank you very much for listening your applause sorry um yeah and so I'm going to not do Q&A here I'm going to go over to the massive village I think Hannah Foy is also going to join us for pre her talk Q&A um so if you go from where we are on that bottom of the arrow up to the massive village by the lake there um I'll go over there and chat to anyone that wants to chat do you have that as a mccarto projector as well do I have sorry it's one it is one right um yeah that will be a project I guess that's probably mccater it's probably too small to notice the difference well um as we are out of time as you said before no Q&A so thank you once once again Matthew