0, because this is the delta, delta is 1 of 0. This is a very useful trick to remember. Whenever you differentiate the inverse of a metric, where one of its indices are contracted with a metric, you can transfer the derivative of the metric at the price of a minus sign. The next thing we remember is that this quantity can be put in terms of diamonds. It should be conveniently constant. So we go very constant to see if the metric is the assertion that del mu of GAA is equal to gamma mu A alpha G alpha A plus gamma mu A alpha G A alpha. Because the derivative is to the left hand side, then we give you the expression to go very del symmetric, which must match. In fact, these are the relations we used to solve for gamma del. So we can now make these expressions and replace them with the metric with these. So what do we get?  Now this was simply this. So this was now gamma with G AM was gamma EO. Take a look now. Thank you. So that was from the first step. That's also right. That's the first step. So from the second step, that's the easiest. Minus mu of mu.   So this is a full set of first step. Now if I can write, these two should cancel against two of these. But look back and see what could be the answer. So let's see. What does this have the property? This has the property that you lower an upper index of a gamma and that index is A. So this is like that and this is like that. So let's compare this step. See here, we take an upper index of a gamma and lower it to make A. And you contract away what is lower in the same and that's mu and mu. Here I take the upper index of a gamma, lower it to make A, contract away mu and mu. This step comes with a plus and this step comes with a minus. Okay. This clearly cancels with this and then of course the mu versus mu also gets this. This cancels with this. So we left with, from the first step of the terms, we left with mu A gamma. Now I'll replace an alpha and I'll replace capital A by beta. Beta, I'm writing another step. Gamma, alpha, mu B. Gamma beta mu B minus gamma. Now this step, mu A and gamma beta mu B. The whole thing multiplied by G. Is this correct? Now this term has all the symmetries in it. Firstly, let's look at A goes to B. Clearly, if A goes to B, you pick up a minus. Because this term means it goes to B. Is this correct? Okay. So symmetry of, anti-symmetry under A goes to B is manifest. Symmetry under pairs is also manifest. And mu goes to B. This term under the pair flip, this term will become gamma B mu gamma mu A minus gamma mu B gamma mu A. Symmetry of the pairs is also manifest. Symmetry of symmetry is also manifest. Why is it manifest? You see, what is this term? This term says you keep A fixed. Okay? Which one goes here and the other goes there? You keep A fixed, so I keep A fixed. Which one goes here and the other goes there? Clear and cyclical permutations of one. Can't see that. We have gave two things. We've got another expression for the curvature tensor, which I've written only in parts, but I'm going to ask you to put together it is. This is the second derivative and this first derivative, please. Okay? The curvature tensor is this plus this. It's a nice expression. It makes many properties of the curvature tensor manifest. And we use that to verify symmetric properties, as well as cyclic assumptions. Any questions about this before we proceed to the Bianchi area? I'm sorry, people. This lecture in the previous one may seem a little boring because it's so algebraic. But I think it's important for us to go through this in class because you shouldn't be left with the feeling that there is anything mysterious about this stuff. This stuff is totally simple, as you see. It's just mindless algebra with nothing to it. However, if you just said that you can check that, I don't know about you, but I somehow feel sometimes, I don't know, can I check it? It looks pretty complicated. I don't know how it looks, OK? So that's the purpose of doing the algebra, not because I'm sure all of you would be able to do it yourselves. But I think we should do it in class anyway, basically, for the purpose of demystification, just to see that it's totally mindless, you know, an idiot, OK? So here, it's just totally straightforward. Everything that we want to do is totally straightforward. Also, let's get some sense of how to do these index manipulations so that when you have to do it yourself, you know. So we're going to, you know, bite, you know, we do a little more of this. We bite the bullet, and just, you know, we're going to exercise ourselves with strength in our muscles by doing the index manipulations. Even though it's a little boring, just to get that. OK? We come to the more exciting stuff. Just imagine doing all of this before you knew that it was correct. It's not totally, not really, you know, you're totally in the dark. You've got this crazy idea that space-time was dynamical. You know, every second day, you're probably thinking, this is totally crazy, I must take a crack for it. And then you have to do all the same index manipulations and stuff, it's totally remarkable that that happened. OK? OK, let's go on. OK, now there is another important identity which the analogy with field strength suggests. And that analogy goes this way. As you know, field strength away a beyond the time limit. This is your familiar with the context of it. In a U-unfairly, you know that it's true that d mu, that if you take the cyclical sum of d alpha f mu nu and cyclically, it gets 0. Why is that?  And clearly, the cyclical sum of this is the cyclical sum. The cyclical sum of this is this. This is just, these two are symmetric. The only question is which one goes here. Cyclically, you sum over all three possibilities. Yeah, but where do you sum over all three possibilities? So, yeah, the famous thing that you know in electric magnetism. And the similar identity is true now in the study of non-abelian gauge theory when you replace the derivative with what's the non-abelian covariant derivative. Now, this is not a constant non-abelian gauge theory, so we want to talk about that. That is, just to suggest that the analogy with the non-abelian gauge theory suggests that a similar identity should be true for the curvature. So when you replace derivatives, of course, by covariant derivatives. Makes no sense to have an identity with ordinary derivatives, but if it's true in one column, it just won't be true in another. That's also when we do the gauge there. In the non-abelian theory, there's covariant derivatives. So, this is the suggestion. This is the suggestion that comes up. So, the suggestion is let's check whether an identity of the form is true that r a b, and now, you see, we should keep the first two indices fixed because they're like the matrix indices. Okay? So, mu mu covalent derivative. Okay, this notation I haven't used so far in the class. Landau-Lichitz uses a many texts used very often. Covalent derivative, ordinary derivative is denoted by comma. Covalent derivative is denoted by semicolon.  Okay, but we might as well do it with lower indices. Why does it matter whether we do lower indices, somebody? Because if you're taking the derivative, why does the difference between, ordinarily, you see, the difference between these two expressions, upper and lower, the difference between these two expressions, upper and lower, is not true here because there's a derivative. So, g lower and g upper, you know, you have to differentiate often doing the lower and upper. But for the special case of lowering the upper and raising to the metric, it doesn't matter because covalent derivative in the metric is same. So, you can furiously raise and lower indices through derivatives, through covalent derivatives because of this wonderful problem. Yeah, so since we can do it as well for... might as well do it. So, is this true? It's a question, right? To actually verify this in full detail, it's, you know, quite an algebraic exercise. But we're going to prove it using a trick. Okay? And the trick, which is a very useful trick, and we've used repeatedly, we could also have used this trick to check that the commutative to covalent derivatives was a curvature. I think we checked last time. But I think we want to do it for the first exercise. Okay? And this... But I know you should start that exercise using that trick. You might want to go ahead and do that. Okay? Here, I'm going to use the trick. And the trick calls up all of us. It says, well, look, this is a tensor equation. Okay? So, if it's true in one covalent system, it's true in any covalent system. Now, is there any, especially in nice coordinates? Yeah, the locally Euclidean coordinates. As we've proved, we can always, at a point, move to a coordinate system where G is eta and the first derivatives of G value. Okay? Fine. We'll use that coordinates. It's probably more convenient for me to use the... Sorry. After having made these things a little lower, I think we'll use the upper one. Okay. Okay? So let's remember what I was doing, for RABs. RAB, mere mu. Now, once again, I've been writing down without looking at the answer, just so that, you know, because it's useful to be able to do and... So, remember what is this? It's del mu of gamma nu. And gamma nu was R gamma AB minus del H mu of gamma nu. Del mu of gamma AB mu. Minus tau. Minus gamma gamma nu. I'm not going to report this right at the indices, because I won't be there. Why would I need that? Because what I'm going to be doing is taking covariant derivatives in this special frame. Gamma's vanish. Now, gamma's vanish means derivative of gamma's vanish. But this is going to product with two gammas when you take the derivative. One of them will always vanish. We don't need to... Look at these things. Is this correct? Because one of them, one of them you can't say... That's not... The derivative is not zero, but the derivative. Gamma's vanish. Okay? Second thing, because we're in this coordinate frame, covariant derivative second ordinary derivative. Gamma's vanish. It's pretty convenient, right? Okay? So, this expression in the special coordinate system, the expression that we had, simply becomes... So, let's write it out. So, simply becomes cyclically superior, cyclic of del between phi mu and mu. Del phi, del mu. Okay? How do I write this? d2 by d xr other gammas.  Cyclically, mu, mu and phi. Obviously, yes. Because what do you do? You permute to take mu. Which of these three is the guy that's special? That comes with b? So, there's one double mu here, one double mu here, one double phi here. Similarly, yes. There's one double mu here, one double mu here, one double phi here. You can't respect what the camera is. This class is not really important. One by fourth of that is... Thank you. Let me do the rest of it. It doesn't see until that part. Yeah, I mean, top part is very... What is this? Reader issues. And this part is completely... Yeah, and this part is completely... Okay, so then we can use this. Entry drop test, as well as... This is the end game. Little algebraic exercise I want to do is the part. If you remember, in the last class, we defined a Ritchie scale. Ritchie scale was A, B, mu, nu. Contract first to third, seventh to fourth. So, first to third, seventh to fourth. We also defined the Ritchie test completely identically that we derived. And from that compute an interesting property that relates derivatives of that Ritchie scale and the Ritchie scale. So, let's rewrite this identity. So, the identity was R, A, B, mu, nu, phi, plus R, A, B, uh, phi, nu, mu, plus R, A, B, uh, phi, mu, nu. This equals zero. In this identity, what I'm going to do is to contract indices like this. A with mu, A with mu and mu. Okay? Because it's a lovely property of covariance derivatives commuting with the metric, you can fearlessly contract through derivatives. So, this term gives us R, not my data file. R, covariance derivative. Okay? What do we get from the other one? Contract A with mu, so, and B with phi. This term gives minus R mu, nu, covariance derivative of mu. Because contract B with phi gives if you're supposed to contract either first or third, or second or fourth to get a plus. If you contract second or third, you get a minus. Either side. Either side. We should contract mu with mu. B with mu. Sorry. I should be contracting B with mu and, uh, this way. So, this is a plus. Plus R, uh, mu, phi, mu. Well, again. So, we should contract A with mu. Then the second. Start with, uh, mu, mu, phi, phi, R. Sorry. I'm cycling people with it. Cycling people. Phi, mu, nu. And one more cycle to go. Nu, phi, mu. Sorry. Let's look at it. So, B with, I'm supposed to contract B with mu. So, B with mu, that's this. And A with phi. So, A with mu. A with mu, huh. Exactly. So, this A is a minus. Because A with mu gives minus. R, B, phi, and then contract B with mu. And this one also, yeah, so we're supposed to contract B with mu. That means a minus. Minus R, mu, phi. Which tells you, mu, phi, mu, is equal to half of R. But you can rewrite this as, in the form that will be of importance to us. As minus delta mu, phi, R, to a very derivative respect to mu. Probably I think in the notation we've been using before. Delta mu, R mu, phi. Minus, oh, half minus delta mu, phi, R, R, R, 2. We finally finished all the basic algebra we want to go through. That's just all. We finally finished all the basic algebra that we want to go through. And now we're, you know, where we're going to start studying this. That's the grunge that will generate the dynamics of the relativization equation. So the grunge that we're going to suggest is the volume. We're going to suggest the volume. We're going to suggest the grunge. 1 over, minus 1 to 16 phi k. This course we're working in units in which the speed of light is set to 1.  Again, this is the grunge that we're going to suggest. Why are you trying to make up the second derivative of mu? Why not consider the derivative of mu in this case? Why are we taking our field as... Well, you've seen that if we do form f mu nu, we get from Christophelsen as we saw in this lecture. We get the coverage.  Why do you... I mean, why do you consider g mu as a field instead of... We can consider gamma as a field. Suppose you try to consider gamma as your field. How many gammas would you have? You'd have 40 of them. Okay? How many g's are there? They're 10. So, gammas are highly redundant. Since they're in A as well, so we can always base... You can. See, what... I mean, it's not that it's impossible. It's that... Okay, let me say this. See, what we're going to do is to write down... Let's try to write down the most general action that we can that is generally coordinated. Now, what you're suggesting is why not write down an action that's not performed. In the end, the question is none of our variables. The question is, why have you chosen this form of variable? You can work in any variable at this point. That's not the hard part. The question is that the analogy with gauge theory suggests that that would be a more accurate question. There are many reasons why... This would not be... You see, if you start looking at gravitational waves, I mean, it is the components of the metric that I've looked at. If you start looking at quantizations of small fluctuations, you're going to have great trouble in the sense of this theory because it's... It is in some sense more accurate. You know, however you think of it. But that's not the important point. Those are finite dimensions. That's much simpler. And the simpler part is that, look, you see, first, before we do anything else, let's do some dimensions. Action. Okay? And action must be dimensions. Okay? Now, what are the dimensions of... What are the dimensions of this square root g-out? So how do we do it? We might assign length dimensions to length and time because c is equal to 1. Okay? Now, ds squared is equal to metric times dx dx. The components will always have dimension in them. That tells you that the metric is dimensionless. So the only dimensions associated with the problem are in derivatives. derivative carries one inverse length dimension, which is something that I will follow in the quantum field theory language referred to as a mass dimension. So you often say h bar equal to 1 in such an inverse length dimension. That's just a term. Inverse length dimension. Okay? Now, if somebody tells me what is the dimension of square root g-out? What's the dimension of... One by L squared. One by L squared, exactly. One by L squared. Because it's two derivatives of dimension. It's either two derivatives of g or gamma times gamma. Each gamma is one derivative. Okay? So one by L squared is this that. Now, if this may be dimensionless, what was the dimension of this? One by L squared. Because this whole thing is like one by L squared. So k has to also be one by L squared. So that cancels. So L squared goes here. Okay? So the dimension of this k, whatever it is, is equal to is the dimension of k No, no, I got it wrong. Sorry. I missed something else. There's d for x. Yeah. Okay, sorry. So what's the dimension of k? Let's repeat that. L squared. Because this is one by L squared. Cancels two of the four length squares. There's length squared remaining. k has to be length squared. Okay. So in such an action here, there is a length scale associated with... There's a length scale associated with this new fundamental constant of k. Which, of course, will be related to new instance. Okay. Now, you see, now let's suppose we make the following constant. Then there is a single length scale. There's a single interesting length scale associated with gravitating dynamics. Actually this constant will be false because the constant will have to be constant. But let's first make this constant and see how far we can go. Suppose that every term in the action is weighted by the same length scale. Suppose this was the case. Then, how do we go behind this? Well, so let's suppose I'm replacing an upright k as equal to L p squared. L p is called a blanket. In the real world, it's said to be about minus than it can say. Okay. Let me write this as L p squared. If I had known like this, what power of length scale would it be? Zero. Okay. This will come with zero and it might have even higher number of terms. Let's say an odd to the four. An odd to the four term will come with what power of L p. Right. So, if we had plus, for instance, odd to the power of four, squared minus g, before x, it will come with like L p squared in the numerator. Now, suppose it is true as it turns out to be the case in the real world. The L p is a very small number. Okay. Suppose L p is a very small number. Then, for physics at some length scale capital L, let's estimate the relative importance of all these terms of nature. Okay. For physics of length scale L, this term will work out whatever its mass dimension is, its length dimension is, which is L p squared. So, this term will contribute like L squared by L p squared. This term will be staying there. And this term will be L p squared by L squared. If we're interested in looking at the motion of the sun around the earth, the earth around the sun, I'm regressing five hundred years. If we're interested in looking at the motion of the earth around the sun, and we'll do the earth sun distance. L p is a fixed number. So, the question is, the layer we are suppose, that there is some unknown dynamics of fundamental scale, that is generating all terms that are allowed by symmetry. Okay. Let's assume that a grid term that is allowed by symmetry is then an action. Four distances. Okay. Four distance at distances long compared to L p. Which is the most important one. Some suspicious reason for that. But you know, when you start to contemplate theory, such arguments can be being quite precise. This is a bit suspicious, because quantum theory doesn't quite work the correct way. But these arguments are made precise and formalized in what's called the Wilsonian renormalization, true. And the interesting thing is that these dimensional analysis kind of arguments often are very good guide to physics. Even when we take into account complicated coupling, basically certainly. I mean, there's nothing to check but if that's just true. The important mechanism. Okay. So, what? What? What the? What the? We've concluded that suppose your excellent question, the real answer to your excellent question about why is such a term is probably a fact. There's some as-here unknown theory, it's a fundamental landscape. Just quantum mechanical. Okay. Which is, when you take that theory, whatever it is, and go down to low energy compared to this blank scale. Okay. You get some effective action that has all the possible terms that are out by symmetry. I mean, actually the terms will be dictated by the dynamics of that theory. But in the absence of knowing what that theory is, we will expect all possible things. Okay. Now, observationally we see LP is extremely small. For this reason, at lens scales is large compared to LP. It's the first term that is of maximum dynamics. Okay. For those of you who are familiar with the study of quantum field theory, this is the general law that terms of lowest mass dimension govern long distances. Okay. This sounds like a very beautiful story. It sounds like I have very plausibly motivated that given that we have general coordinate and variance and so on, Einstein's action should be the right action. But there's a big j-pick hole in this, in this, in summary point. If you take my logic to completion, there is one more term you can add to this action that is even more important at long distances. Which one? Root G. Root G. What's wrong with this G? Why power of LP will come with 1 by LP to the power of 4? This is what you will expect. This will affect most of all. Okay. Okay. So, of course, the term by itself is totally true. Not yet. This will give you two different equations of motion. I mean inconsistent equations. Now, if you add this to this, what you can find is that the only solutions are universes which are curved and let's say 90. So, if you took the logic that I was applying for you and took it through a completion you would relate that we have a universe whose curvature scale is 10 to the power minus 33 centimetres, which unfortunately is totally wrong. Is 1, 100? Okay. Sure of its suffice, sophisticated, this is what the question of why this prediction of gravity is totally wrong. Why this prediction? It's not prediction of gravity. It's prediction of being 90. What you're saying is knowing nothing else, you predict that all terms allowed by symmetry are generated. And that's how it works pretty well. We get the second term. That's somehow not the first term. Probably what must be the case is that once we understand the correct theory of gravity, presumably the correct quantum theory of gravity, it will help us understand why this cosmological constant term is not generated, was actually generated any smaller. Now, until the end of the 1990s everyone had every, most theoretical set as you, that since the cosmological constant is so small and blank units, clearly the fact that the universe is big that the cosmological constant can't be, is approximately is less than or equal to the inverse size of the universe. So what, that if such a term appears it's not having surprised by 1 over L, 3 to the 4, but 1 over Hubble scale. Size of the universe. There's a huge distance between delta minus 3 and size of the universe. So since this, since I was a huge hierarchy, I think most theoretical physicists, certainly when I started my PhD, it was commonly known that the cosmological constant 0. However, it's got observational evidence that this is probably not the case. Okay. So now there are two mysteries. First question is, why isn't it 0? And the second question is, why isn't it 0? In the sense that it's really 0. Nobody had a good idea for why that was the case. But at least 0 is a good number. You can imagine explaining 0. But now, it's got even worse. How are you going to explain that it's not 0? But enormously small. Okay. Right. So this argument that I gave you, there's this nice beautiful dimension analysis argument that sounds so nice, has this big gaping hole in it. And I would say this, this big gaping hole is one of the important elephant in the room in theory, in fundamental theory. Because every, every way you have of trying to understand the gravitational theory from a fundamental point of view, would predict that the universe was curved at a much smaller lens scale than we see it. And that's obviously not. Okay. So it's a startling gaping fact that fundamental physicists have failed to account for, for 50 years, 60 years. And you know, it's one of these, it's one of these things.  That's because little benefits, you know, specific curves. More detail, you have the better. But this is one of these things. It's an obvious contradiction between what we think we know how to predict and what we see. And it's resolution is awaited. Okay. This is a very important question we get. Now, this is the cause and I don't know what the answer to this. It's a cosmological question. It's a cosmological question. It's a very, a lot of very disquieting talk. You know, something to try to explain it by saying, look, but what's called the anthropic question. Which says that, look, if the universe was very, was very, very highly curved, then, you know, you wouldn't have galaxies, you wouldn't have matter, you wouldn't have people living inside planets to observe the universe. So, maybe somehow, for some reason or the other, the eternal inflation, there's a whole ensemble of universes. Most of which are very highly curved. Once in a while, you come about to the universe, it's a big curvature. And the question is, why are we so incredibly lucky as to live in that one? It's like, because we couldn't have lived in any other. Okay. Now, this may be a certain, sophisticated, just because, it's a cute argument, but I don't think it's business. You know, once you start getting into these kind of discussions, you're going very near to kind of things, you know, philosophies. And that has led us nowhere. You know, what we want is something with equations, which we can predict with, which we can make progress with, and if this is the best we can do, I would say, we're giving up on business. Okay. People won't even let to such disparaging arguments, because they haven't been able to think of anything better. Okay. And I think that's true. And it's your job. You know, you are the fresh new generation.  The right crazy idea that will help us understand why this is happening. Okay. What would this be? I don't know. How do I explain this? Okay. But I haven't said all of this. Maybe I should sweep it out of the college. I do. A view that for some reason, this argument which does not work in predicting that a big first term works in giving you a second term and all other terms will be highest and best. That has an extremely good confirmation from the expert. At least from the expert, we know that it's true that at reasonable landscapes, the term that governs interactions is square root j. And had it not been for this elephant in the room, they would have been very reasonable argument. Okay. We should take an old argument with many pinches of salt because of the elephant. But let's move on. Okay. So this is Einstein's action. This is the action you don't have without this one. And we're going to invest in this course we're going to study. We're going to study this action. And then what we want to do is understand this action a little bit. So now we have two parts to this action. What we're going to do is, of course, we're going to take the action and get it moving to motion by varying this action with respect to the action. Please. Yes? Yes. Other terms also? Then all terms are equally important. So if they're interested in physics, those others, then using just plain Einstein's action is completely understandable. F-R theory is a guarantee. But those are very specific theories of that. Because they keep some terms from knowledge. Now, you know, if you just try to keep all possible terms, you'll more or less lose predictability. So basically what this is telling you is that once you get a length scale small compared to the order of the prime scale, then you know you need the correct quantum theory of gravity that tells you what the right action is. Crude symmetry analysis is not correct. You need to know what the right theory is. Once we start trying to understand the right sense of feedback or something like that, we need that. That's a great way to understand quantum. Unfortunately we're not going to be able to do that because I don't know how to understand this. Okay? But these are great questions. Excellent. So, let's move on. We're going to make this action and vary it with respect to the metric to get the Einstein equation to motion. Now, we vary it in two parts. There's a variation of minus square root of gr and then there's a variation of square root of g in the magnetic field. Both terms are important. Okay? When you start by starting the variation of square root of g in the magnetic field, let me take an example. Let me take the max value of the the max value of the gun in the magnetic field. Okay?  Let me take this function and vary it with respect to the metric field and let me choose the metric with the upper components of my basic equation. Then g mu alpha and g mu alpha. Yes, that's true. With respect to the metric field. Okay. So, there are two sources of variation. Because we're contracting like this and varying with respect to g mu. So, delta s is equal to minus 1 by 4.  Okay?  We'll make it half because there are two such terms. Okay? Or minus 1 by 4 out. And write 2. And this term has this mu and mu contracted. It doesn't. And then delta g alpha. That's one such term. Okay? There are two possibilities. They're both the same. That's clear. We should also vary g inside the determinant. So, we have to learn how to take variation of the determinant. So, let's learn. Remember, is that you can take a determinant and write it as g. What you remember is this. That there is a name for the coefficient in a determinant. Suppose you've got a determinant. You take the determinant and look at the coefficient of a particular element in that term. There's a name for that coefficient. It's called the mind element. Okay? You see, a determinant cannot have any element in the matrix at higher than linear order. So, all terms are either if we fix on a given element in the matrix. All terms in that determinant, either of all is zero. I independent of that element or of order one. The coefficient of the order one piece, the path that is linear at that element, is the minor of that. Okay? So, let me, suppose I've got a matrix g alpha beta. Let me denote by the minor of g alpha beta. Let me denote it as m r. This is the minor. This tells us that the variation of a determinant. This, what is that? That's equal to the variation of the determinant with respect to each element times the variation of that element. I'll call it m. Is this clear? Because the derivative of the determinant with respect to that element is the minor. And that begins the check. This is del determined by del g alpha. That is equal to del g by del. And this is just a derivative check. Is this clear? Now, this is a nice formula but it's in terms of this irritated minor. Okay? This minor is related to some other object of the matrix. It's inverse. So, g inverse is equal to m in transpose. In transpose. Divided by g. And how do you know that? You know that because if you now multiply by g on this, when you take the sum, you get a minor to give you the determinant instead of giving you delta. So, this is a familiar formula from the study of matrices. So, we can rewrite this at least for some time. I would have to think through the transpose part but we don't care because we're dealing with symmetric matrices. We can rewrite this in this case as g alpha beta. That's the inverse of g. That's the g alpha. A formula for variation of the determinant. Now, we're interested in varying this determinant. We're interested in varying this determinant. We're interested in varying this determinant with respect to the upward. Can you tell me what the right formula would be? You see, just from the fact that if you contract these, you get a number. You just transfer this delta. Yeah? We expect a minus. Minus delta g alpha beta. G alpha beta. Just parenthetically, you might be wondering what's making the symmetry between the metric and the inverse. You see, from the point of view of the determinant, the determinant of g is one of the determinant g's. Okay? So, let me call g prime as debt g inverse. Okay? So, of course, it must be true that delta g prime is given by this formula, where everything is replaced by g prime. Equal to g alpha beta delta g alpha beta g prime. Can you see that these two are the same formulas? They're the same, because g prime is one like g. Delta of one by g is equal to g alpha beta delta g alpha beta by g. Now, defensive. So, that implies that delta g is equal to minus delta one by g. It's minus one by g. G g alpha beta delta g. So, we have another way of getting this information. What is it? When is your next class? 11. 11. 11. Okay. So, let's add that to the other class. So, what we got is minus one by four. And now, we get, now, so far, what have we got? Delta g is equal to g alpha delta minus g alpha beta g alpha beta g. What we want is delta square root of minus. Okay? So, delta of square root of minus g is equal to minus half by square root of minus g times delta g is equal to minus half times minus delta g alpha beta g alpha beta into g by square root of minus g. Now, I'll take this minus in here and write this as minus half into delta g alpha beta and g alpha beta square root of minus g. Let's put everything together. Putting everything together what we get.  I want you to know this. The first thing is that so, let me write down Einstein's equations. This will be one of the contributions. It's the coefficient of delta g variation if you have an electromagnetic field. But in more generality I'm going to make a couple of definitions. Fine, right? The by definition is going to be associated with this is by definition going to be called half times square root of minus g times t alpha beta delta g alpha. So, whatever you get by varying the matter part of the action with respect to electromagnetic field it always takes this form. This is necessarily true from general point of view. Square root g times the tensor and delta g alpha beta. That tensor whatever it is you're going to be defined as a stress energy tensor. So, for the electromagnetic field we've concluded that t alpha beta is equal to minus 1 by 4 f alpha theta f beta theta minus half g alpha beta. So, this is just an example. In general, whatever you get by varying the matter field we're going to call the stress energy. Okay, now there is a very important property of the stress energy tensor. Okay, we're going to now try to prove stress energy tensor is basically up to one subtlety, the same thing as the nother column for space time transitions. And because of that the basic property of a nother column is that it gives us a conserved I mean that there's conserved column that's what's here. Okay, and so while we're going to prove to you is that this stress energy tensor that comes from an arbitrary matter field is conserved obeys a conservation technique. Okay, and prove the very simple we had in the class for this. It's very simple to require to almost know how to do that. I think, how does it go? Let's see. You see, consider an action that is minus G, minus G and then I think lambda is some function of some matter field. The matter field could be a mu like in electricalness. I make a coordinate transformation on this action. The action remains in there. How does coordinate transformation happen? A coordinate transformation changes the matrix. But a coordinate transformation also changes the matter field. Okay? But on shell but we independently know that from the equations of motion for the matter field the variation of the action with respect to arbitrary changes in the matter field to first order that change punishes by the equations of motion. Two zeroes. The first zero is kinematic. Any change that changes both the metric as well as the matter field in a way that is a coordinate transformation does not change the action. The second zero is dynamic. On the solution to the equations of motion and arbitrary variation of the action with respect to just the matter field is balanced. What do we conclude? We conclude that on a solution to the equations of motion the variation of the action with respect to a coordinate change just on the metric must vanish. How does a coordinate change act on the metric? Okay, when we have a small change in coordinates how does this act on the metric? Now, a minute what kind of thing we talked about in the first couple of cases? You see, a change in coordinates acts in two ways. It acts inside the attribute of the metric and it acts by transforming the imprecise of the metric. Let me put this in a problem set which we will definitely get next week. Okay? Let me put in a problem set the following thing to show that under infinity as in the coordinate transformation given action has to be a problem. Suppose we have X mu is equal to X mu plus zeta mu. Part of the reason we have under the problem sets together is that your teaching assistant seems to have a right. Something. What? Somebody see that? Yeah. Okay, suppose we got what the change of this form? X mu is equal. Okay? Then up to a sign that I can't remember that we will get straight when we give you a problem set delta G mu, which is G prime minus G is equal to del mu of zeta mu minus del mu of zeta mu. But then it's covariant. This is not obvious from what I've told you. But it's true and you'll prove this. What do we find? You see, what we had was that by definition the variation of this action with respect to G, G alpha for arbitrary variation with respect to G alpha, beta first half square root minus G T alpha, beta, delta G alpha, beta. This is always true. But we've concluded from our logic that the variation with respect to those changes of the method that come from a coordinate transformation must vanish on solution sequence. Okay? So we've concluded that it must be that half square root minus G of T alpha, beta del alpha strongest zeta, beta plus del A in W Symmetrical. Now del beta, zeta, alpha is equal to 0. Now, this is symmetric. So these two terms are the same thing. So that implies that minus square root minus G T alpha, beta del alpha zeta, beta is equal to 0. How about 3 zeta, beta? How about you just use this to do something for this T alpha? So first thing we do is use the gene. We write this as square root minus G del alpha of T alpha, beta zeta, beta minus the alpha now we get minus square root minus G of del alpha, T alpha, beta beta, zeta, beta is equal to 0 because we go right there to the basic chain rule. Okay? And now this thing has a vector in it. And do you remember we have this nice formula for the divergence of a vector? We have covariant divergence del alpha of zeta any any vector is equal to 1 by square root minus G del alpha square root minus G theta we derive this in one of our analysis. Let's use that formula. So this term that makes that term the 1 by square root G cancels the square root G. So it becomes del alpha of square root minus G T alpha, beta zeta, beta and therefore this is a total net. So if we focus on zeta you know we take some action that's a boundary term we look at zeta as the banished of the boundary the quantum transfer is to complete the variance. We look at such quantum transformations the banished and the boundary are non-zero away from the set region only in a set region this is our banished in order to use Gauss's law and make it the surface integral this is an ordinary derivative Gauss's law works for ordinary derivatives it's just a studio statement of integration doesn't work for ordinary derivatives and in this case this very integral is converted into an ordinary derivative nicely canceling the square root G cancels otherwise we couldn't make this up Once we have that now everything seems to be banished so what we conclude is that this term is zero but this is zero for arbitrary Zeta, beta therefore it must be a del alpha of T alpha, beta the stress tensor defined through this definition as the variation of the matter part of the action with respect to the upper part of the metric as a property that it is necessarily automatically conserved is this clear where do we find Einstein's action we will find some equation of the source sometimes alpha beta that comes from there in the Einstein part of the action it's completely alpha that's clear but this T alpha beta is not something arbitrary it's automatically conserved now can you use that to guess what this is going to be why? look at this part you see if you have the equation that's true it must be true of the variation derot is on both sides remains true okay this thing as a property that it's covalent derot is zero see the way we get on the left hand side no we don't it's some constant right side now Einstein when he tried to run down the general result he made many false attempts and one of the problem that falls at them was to make run down the equation r alpha beta is equal to T alpha Einstein was not thinking he was just writing down equations of motion not thinking so much through the action so it just wrote down this equation and it took some time to realize that it was obviously wrong because it was inconsistent derotive on both sides now at the same time that Einstein was working you know these guys Hilbert and a few other people were you know were deeply investigating the geometry of arbitrary curve spaces and Hilbert and friends knew the stuff very well they knew of the right combination of curvature of that that vanished under governing derot they written it down before so the action the Einstein action is often called the Einstein Hilbert for various reasons Hilbert himself though was very modest about his contributions to general derot even when asked about whether he thought he'd done the important stuff he said something like well any child in Grottingham knew the combination of curvature that was vanished under governing derot that wasn't the important thing the real story was about that man in the element so in the next class people actually derive the Einstein part of the or the Hilbert part of the Einstein action by varying square root Gr then we will have Einstein's equations in our hand then we'll be ready sorry for being too busy see you guys tomorrow at the evening


Well, it's hot It was cold because it's yesterday. Oh, did you heat it up? Yeah? I added I added spicy ketchup to it He did it up in a different kind of heat. Yes Scott, what'd you have? I had a Mushroom and Swiss from the habit Yeah, we're talking like a sandwich or a burger burger and it was great And I should have probably gotten a chef's salad now that Tom mentions it, but What do you have Sarah? I had a A Breakfast taco that is you know for lunch also perfectly fine Yeah, yeah to corn tortillas eggs avocado tomato arugula that Very good. So yeah, sort of a California twist on the breakfast taco It was delicious. I Had a mandarin orange for dessert Yeah, maybe you can have a Cantonese melon or dinner It's a very bureaucratic orange an English loaf Are there any are any are there any dishes that have like Like either linguistic I don't know under that while we do Daily Tech news show and we'll get back french fries. Oh, yes Yes Belgian waffles. All right. Here we go. You guys are ready. Yep in three two Dave Broadbeck has supported independent tech news directly for five years be like Dave become a DTMS member at patreon.com DTNS This is the Daily Tech news for Wednesday May 15th 2019 in Los Angeles. I'm Tom Merritt and from studio feline I'm Sarah Lane from Salt Lake City Dave Broadbeck fan Scott Johnson And I'm the show's producer Roger Yes, indeed folks. We have a load of tech news including the translatotron a ban on facial recognition in a high Profile Western City rhymes with Bam Benzisco Let's start with a few tech things you should know Google announced new ad types coming to its mobile services search We'll have gallery ads that let advertisers display multiple images that users can swipe through ads will show Up in the Google Discover feed in the Google app on Android homepages and on YouTube But not on Google.com for mobile interesting well DJI Launched its Osmo action rugged eyes rugged eyes. That's correct Compact camera a competitor with the GoPro hero You may be familiar with that model the Osmo action can capture 12 megapixel photos 4k and 4k HDR video has electronic image stabilization and is dust proof shock proof an up to five feet Or excuse me shock proof up to five feet and waterproof down to 36 Freakin feet. That's pretty good It has a 2.25 inch touchscreen on the back and a 1.4 inch on the front with the Osmo action costs $349 and is available right this second fans of specter and meltdown. Please welcome Zombie load. That's right security researchers discovered four bugs in speculative execution on Intel chips Which they call zombie load one of the researchers Daniel Gruss told TechCrunch It was easier to exploit than specter but more difficult than meltdown Almost every computer running on Intel chips dating back to 2011 is affected including virtual machines It does not seem to affect AMD though or arm Intel has released microcode to patch the bugs Apple Microsoft and Google have Also released patches. It has not been found in the wild yet But while most users are at extremely low risk from it as always we advise you to promptly update your software Facebook announced that users who violate its most serious content policy against dangerous individuals and organizations Will be suspended from using Facebook live video for set periods of time Starting with 30 day suspensions for the first offense. Yes one and done other restrictions against things like purchasing ads will also apply Oh, let's talk about another vulnerability Scott Well, Microsoft has had their share of them over the years But also has issued a software update to patch a crucial and critical remote code execution vulnerability in remote desktop services aka rds in windows xp windows 7 windows server 2003 Yes, people are still running that windows server 2008 r2 and windows server 2008 Manual downloads of patches are available for xp and server 2003 despite the fact that both operating systems are no longer being supported In fact, seven was just added to that list and will soon be not supported Anyway, the vulnerability is a pre authentication and requires no user interaction similar to the want to cry malware Windows 8 and windows 10 are not vulnerable in this case Yeah, this is interesting for multiple reasons one good on Microsoft for patching something even though They don't officially support it There are a few contracts to provide security patches for windows xp users out there like specific contracts Which means it probably wasn't costly to create the patch since they would have to create it for those clients Anyway, but they are making this available as a manual download to anybody who has windows xp or windows 7 despite the fact That they don't want you to continue to use them Which implies to me that they think this is a very serious vulnerability the way want to cry was You know the the thing about these these kinds of malware is they're wormable So you don't have to do anything for them to infect you and then move on and start infecting other machines on the network Which is unfortunate because a lot of folks who use windows xp I'm not just talking about personal users out there small businesses and and places like that May not Bother to go download the manual update and patch their xp in which case they'll probably get infected Yeah, you knew you you say tom good on microsoft and indeed that's the case But it does point to you know microsoft could easily say well Just don't use this like crazy outdated version of windows You know we've been telling you this for years But the fact that they're like male enough people just don't listen and still are using that or for whatever reason just You know can't upgrade This is serious enough that it needed to be addressed Well, that's the part that grabbed me is that they there aren't obviously there are enough xp machines in the wild and server 2003 and whatever else That they have to they had to go back and sort of Work outside their normal, you know support system for operating systems. They no longer act 4% of the market, uh, still have still runs on xp. That's just crazy to me But I guess it's I mean that's a big enough deal where i'm glad i'm both glad that they're doing it But also It reminded me that we still have a whole lot of old operating systems out there that are they're vulnerable So good on that. Yeah, you know, there there are companies that have mindfully not upgraded from xp They'll they have internal software. They don't want to recode those people will probably go and download this update They may even have a client contract with microsoft because of it But it's the you know odd xp user out there who's just dusting off his old dell or maybe a small business That just doesn't want to pay to upgrade. That's the ones you gotta worry about Google has released an app called rivet developed by its experimental workshop area 120 Rivet contains more than 2000 free books for kids along with an assistant that uses speech tech to help kids They can get stuck on a word who are you know trying to learn to read and and maybe need a little bit more help The app can read a word out when it's tapped Or listen to the child's own read and then tell the child which words they said write as well as proactively jump in When it can tell that a child might be having a hard time sounding something out It also uses includes definitions and translations in more than 25 languages So this is going to apply to a lot of kids rivet is also available on the app store and google play store for free in 11 countries When I first read this this morning, I was like, huh, okay Yeah, I mean I remember when I was learning to read, you know, we had those sort of like it was like little record player You know like 45 records and books and it would ding when you're supposed to turn the page So you kind of felt like you were reading before you were actually ready to read and there was probably some Reading retention that happened. But this is next level Oh, yeah, like I I mean My kids are all fine readers now and have been through the rigors of Of their junior high high school and even in a couple of cases college course Uh reading material and they're just fine But had this been available when they were little and they were just starting to get Uh, you know reading skills even as young as I don't know My daughter was reading it two and a half or three In a really rudimentary way my oldest she would have benefited hugely from this and so I hope it's uh Something parents get a hold of and I hope teachers don't see it as like, you know Robots are taking my job because every time I see a story like this I think well if we get really good at this like really good at it Then who needs an english teacher, but we're not there yet Everybody calm down about this fake emergency. I just announced You created the emergency you now need to calm people down It's sort of like how I feel about google translate I use google translate somewhat often. It's not the same as a french tutor But it's definitely a supplemental thing that helps me I can learn as I'm as I'm you know as I'm studying on my own Yeah, I don't mean to suggest that this would replace reading with your child But this is trying to emulate some of the best parts of reading with your child when you read with your child You help them out when they get stuck you can tell like oh, you're having trouble You know look let me tell you what that word is or they may point at a word and go What is that word and you say it and this gene learning can do some of those things which Doesn't mean you shouldn't still read with your child But there are times when you don't you just let your child read on their own and when they make mistakes They get no reinforcement on that So this is supplemental to you reading with your child when when they're reading on their own They can get some feedback and and you know help speed them along Unlike walt disney's lady and the tramp bozo approved record reader I had that one I really had that one as the little book inside and the 45 that goes ding Well, and there's also you know There are lots of reasons that a child might be tripped up by reading dyslexia You know it's something that can can be overcome But you have to identify that beforehand, you know, it's it's different than a kid Just being like I'm just getting used to this whole reading thing and and you know kind of memorization of What words are like so? If if the app can help identify things that need to be addressed sooner than later, that's really cool Yeah, my sister who's a she has a master's degree in Psychology and she's super smart. She always has been and I always noticed something she was young She would read out loud no matter what it was and you could hear her up the hall All night just reading out loud and annunciating everything And I used to think that was crazy I now think it was really smart and now we have an app or a service or a technology that perhaps Would even aid somebody like her who swears that she the reason she got anywhere was because she read out loud So now kids can do it along with an app and it can tell you when you're wrong or you're right speed you along the way I was thinking of google translate. There's a research project at a google called translatotron That not only translate what you speak But delivers the translation as spoken word as an audiophile in your voice and cadence It works by not doing the normal three-step process Of uh, you know, we're recognizing what you said turning that into text Then translating the words in the text and trying to put it back together in syntax and the translation And then doing text to speech to read it back. No, no, no This just converts the spectrogram of your speech Using a machine learning algorithm to be able to identify like oh that speech pattern usually means this phrase So that it is turning your own speech into another language The accuracy is not yet as good as the slower three-step process that I just talked about But it's pretty good. In fact, uh, they put a couple of examples up on their blog post about this So here is an example of an input in spanish Larry me pregunto como me sentía y creo que es cuando empecé a llorar And here's what translatotron spits back out. Larry asked you how I felt And I think it's when I started to cry Now when we were listening to this in the pre show scott pointed out like a second guy sounds like maybe uh, he could use disober Up a little bit So the annunciation isn't exactly the same but you can tell like, oh no, that's that's that original guy's voice And you can understand what he's saying Yeah, it's really cool. I I uh, I would assume well Unusual google fashion the name's terrible change the name translatotron. You don't think translatotron is a cool name That's something I don't know some of that it rubs me wrong, but maybe it'll sound like something in like 1962 You'd like. Yeah, I think Lady in the trap By the way, we've buried the lead this whole show how tom has that record handy is yet another magic trick by the Anyway, this is a really uh neat thing. We've gotten pretty good at And also by the way the text of that translation I don't know if that was accurate or not, but the english translation sounded kind of nonsensical So I don't know if that's okay. Here's here's the actual translation here. Here's the spanish again. Okay, larry me Pregunto como me sentía y creo que es cuando empecé a llorar. Here's the reference translation This is the actual translation larry asked me how I felt and I think that is when I started to cry larry asked you how I felt and I think it's when I started to cry Interesting, okay, I mean neither of them really sound like the original to me But I get what they're going for and I think I think that yeah, sure This is a first iteration of something where um, and I have had conversations with somebody You know, we're both like using google translate and then like robot voice, you know Tell him what sarah meant to say in the beginning like you know, like that that it's clunky. It kind of works But it's definitely clunky. Um, this is you know, once this becomes more seamless. This is absolutely cool And we shouldn't lose sight of the fact this is a research project, right? They're showing like look what we did not Here's a product ready for you to consume yet. So I'm pretty impressed at the ability for it to just look at a spectrogram And come up with something that translates that well, even if it does sound a little bit like it needs a cup of coffee Well, I'll tell you who else needs coffee. United States FCC chairman a jeep pie. Not really He's probably fine He is proposing a clarification to FCC rules to make it clear that carriers Can implement blocking of robo calls? Oh, everyone loves a good robo call by default. All right as long as they Sorry, as long as they as long as a way is offered for our consumers and customers to opt out of the blocking The rules would not prevent carriers from charging for blocking services A 2015 FCC order was unclear whether opt-in was required or not Or not so most carriers and uh aired on the side of caution pie's proposal And a proposed clarification would be up for vote on june 6 so real soon pie hopes it would lead to further innovations Like and this is a quote blocking based on contact lists Which the new rules also make clear would be allowed the rules go into effect if they pass on a vote Which will happen again on june 6th I just got one during the recording by the way A robo call so it seems appropriate that it happened just now You know when I first read this this morning because I get a lot of robo calls I'm used to no longer answering my phone if any phone number comes in that looks remotely like my own because I know that That's what it is But they still get me every once in a while and it has become a real epidemic And I know i'm not alone in this like robo call Volume that I've gotten in the last two years is like You know 4x what I used to get but And I my carrier happens to be of ryzen if i'm going to be charged for blocking robo calls That's pretty annoying Yeah, I mean It seems to be a cross-purpose is a little although aji pie does go out of his way to say We would hope that carriers would provide this for free because it would reduce costs on their network to block robo calls Because I'm sure you would hope yes, you know Well, but he makes a good point, uh, whatever you think of him He makes a good point here, which is it actually is cheaper to just block robo calls Then deal with the fallout from robo calls increased use of your network for one thing And all of the support calls you might get from people complaining about robo calls, right? That doesn't mean the carriers will do it though. You're absolutely right They may try to charge in which case it's opt-in If if you if they're charging you because you have to agree to the payment If you don't pay they're not going to block your calls for you anymore So hopefully they they implement it for free Although john brodkin and ars tecnica was less hopeful about it than I am because he says they currently charge you For robo call blocking on carriers right now. Why would they stop? Why yeah, it's like, hey, do you want a better version of this carrier service? Then pay us and we'll give you a better version of this carrier service I also am jealous of anybody who's like, you know what I got 20 people on my contact list Where I don't know how whatever the number is. I don't need anybody else I'm just going to go ahead and block everybody that's not in my contacts I wish I could do that if I could do that my life would be so much more simple But you do get random calls from numbers that sometimes are legitimate and I I wouldn't feel comfortable doing that person By default, I'll go ahead. Go ahead. Well, and there's also third party software that can do that for you right now You don't have to wait for the carriers to sure and by default ios lets me make a contact list or My favorites list rather and so the favorites column They'll always supersede the sleep function where I'm saying do not disturb the little moon Um, so they'll come through whether I got the moon on or not That's maybe a way to do it But all the names you want on there that you want to get and then just put your phone on moon for the rest of the Time and nobody else can get in that might work. Yeah, I like it better at the operating system level myself Oh, I would too. Yeah Well, maybe you'll like this gentleman the city of san francisco's board of supervisors voted 8 to 1 to prohibit city personnel From purchasing and using facial recognition technology The ordinance additionally requires city departments to submit surveillance technology policies for public vetting The ordinance will need to pass a second vote by the same board next week to become final But it appears to be On its way. Yeah, I mean, there's no reason if it was 8 to 1 it's it's not going to suddenly Like five five board supervisors are not going to flip by next week. So it's just you know, the way san francisco runs It's stuff. It's not actually an inactive or it's not actually an active ordinance today, but it will be sounds like and Yeah, mixed feelings about it. There's there's two things going on here one san francisco is a famously liberal city And so it is very concerned about the rights Of its citizens, especially minorities and there's a lot of legitimate concern about facial recognition providing false positives And when it provides false positives, it ends up harassing minority residents out of proportion Which is not good. So so there's that concern. There's also the tech backlash in san francisco There's there's a lot of anger with the tech companies and the people who work at the tech companies things like, you know Protests and blocking buses and that probably fed this a little bit too Like let's slap down these tech companies like amazon and even microsoft who's called for regulation of this But they still provide it Who provide this facial recognition technology? So there's a couple of motivations behind this I don't know that banning it outright gets us to the place we need with facial recognition Which is to make it free of bias or as free of bias as possible And to see if it can be accurate enough to be helpful to law enforcement banning it outright Won't allow us to experiment there But the fact of the matter is city of san francisco is banning it That doesn't mean all the cities in the world will ban it. Uh, the uk has been trialing it So we'll get plenty of research on that eventually. Yeah, I mean we have a lot of examples of cities that are doing exactly the opposite Who are like, hey, you know, we got it. We got to make this technology better Um, and we're on our way, but we're committed to doing that san francisco is just like nope doesn't work Yeah, they they like tom says there's so much backlash right now I mean I hear it from people who live there in the tech sector Who are kind of annoyed at being the guinea pig every time some new tech comes along And this is certainly not the first time anyone's being asked to one's being asked to try this technology But to sort of blanket ban it in this way Seems a little rushed like I I think you maybe should just leave your options open for later when the tech improves or when there's reasons It may Sure, there's always a chance they could none of this is in stone, but Um, I guess I'm just not surprised they're being, you know, they're wearing gloves on this one and I think I get it Well, uh folks from netflix are going to host a panel at the e3 conference You know that e3 conference got the video about the video games Yeah, netflix panel is called bringing your favorite shows to life Developing netflix originals into video games and on twitter netflix did that thing where it very cutely asked e3 if it was busy in june and could have stopped by and talk and hang out and Promoting this panel and in the course of that conversation mentioned the upcoming stranger things game Which looks like kind of an 8-bit take which would be in character with stranger things now netflix has said in the past It's not getting into gaming So it's a lot of people are like, oh, you're not getting into gaming where you're doing a panel at e3 There's lots of ways for companies to not get it into gaming and still be involved in gaming One is to contract people to make a stranger things game for you And I imagine that will be the discussion on the panel is what are the best ways for us To turn netflix properties into video games without becoming a video game company Yeah, and they've already done like there's a stranger things game on android and ios that was pretty successful I believe came between seasons one and two Did okay, um, they're talking about more of that obviously a lot of people are going to jump to the conclusion I think it's a fair conclusion when they when they get up there will be both about their properties And what could come from games based on them? But I think they may also talk a bit about what they did with black mirror With the recent experiment of sort of choose your own adventure style gaming They did this with the the the minecraft game or excuse me the minecraft game that's built in there Now a lot of these are very um At least right now they're like dragonslayer for those listening who know what i'm talking about where It's kind of predetermined in a lot of ways But you may have points at which you can make a choice And so if you make a choice a lot of times it's very binary. You get one or the other Yeah That that maybe is the most advanced version of what this is but Otherwise they've sort of dabbled in small ways To do the city three, I feel like they got to say more than just hey We're hoping to license our cool shows out. I think they're going to get up there and say that but also We're now going to go This much further in interactive storytelling And it means multiple endings because we're going to come up with technologies that generate the results on the fly and give you You know, maybe CGI that looks like it's a real production, but really you determined where it went or or whatever It also also this whole thing kind of Points to the idea that e3 is changing Sony is not presenting this year Um ea is not there a whole bunch of uh big studios and publishers are not there And as a result you're seeing kind of odd stuff crop up this I would say is one of those So i'm interested in that fact alone just to kind of see what e3 is from years from now Because it may be a very different kind of show and less about poor gaming and more about integrated entertainment Um and netflix is you know Who who better position right now than them? Well, and it kind of you know, I think like okay Let's just say this whole thing becomes something more than a novelty like how will A television show or a movie That maybe you know that people involved in production say like this could be a great game like how does that? Um dictate the plot line and the story overall Right. Well, that's the that's the question like if they're just talking strict licensing Then they do it like everybody else does if you're making a game I was just recently replaying 2015's game based on mad max called mad max um about the time fury road came out and They when they do those sort of deals Wb makes the deal and the publisher and the developers get together and they sit down with the creators of the content IP holders and they say All right. Well, we think this is overall the kind of game we want it to be and here's mechanically What I think the players will be doing and then you build the game out that way and you make changes as you go And then you go for your release That's very possible We could see things like bird box and I don't know what all but i'm Unbreakable kimmy schmidt is going to be an interactive storytelling like They did with black mirror and they also did a man versus wild type one recently as well So they've been trying different genres in this interactive storytelling and the one thing netflix has been saying Is we want to do interactive storytelling? We don't want to get in video games We want to do interactive storytelling So i'll be very curious how this panel walks that line to say well our interactive storytelling will take you this far And then maybe we'll hand you off to a game that a partner has developed that you can play on such and such platform Yeah, and it could be both. There's no reason two things can't happen here um I think the bigger issue is well viewers traditional viewers like all this like will they do they want to have all this programmatic Kind of algorithmic choice making in in movies. Do they want to have their movies and their video games in the same place? I'm not so sure. I don't know actually. I'm not really compelled by it because again, they're very binary choices There's only so many endings you can pre-film For how things end up in black mirror so It's it's not the most dynamic kind of quote-unquote gaming scenario But there's probably ground to do more and certainly they could do more programmatically. You could do more with data flying back and forth between a user player viewer and and netflix So i mean clearly they think they've got more here to show so it's going to be super interesting in june To hear what they actually have to say on stage Well, folks if you want to get all the tech headlines each day in about five minutes Don't forget you can subscribe to at daily tech headlines.com Also, thanks to everybody who participates in our subreddit You're the best submit stories and vote on them at daily tech news show dot reddit.com If you hang out on facebook join our group if you haven't already facebook.com slash groups slash daily tech news show What's in the mailbag? Oh tom i'm glad you asked uh, so on gdi yesterday We uh, we we mentioned that my my next live with it segment Which is me living with new technology for three months is going to be Smart bulbs and they came today in the mail in fact Oh, yeah, that was bad. I know we got we got four phillips hues The whites the whites and then we got and tom remind me how I say lithics life acts life acts We got two life axes So we're we're gonna we're gonna test a couple models out And i'm really excited about this because I don't have any smart bulbs never have And now I will uh, and we got some really good feedback I just want to read a couple the first one comes from Todd Todd says I recommend getting the hue colored lights instead of the just white lights a little too late for that Todd but Todd says having the ability to set colors really expands the ability of smart lights I have some 16 in my house so I can speak with some authority I use some of them as wake-up routines to simulate a sunrise Where they start as red and they're dim and they gradually change to bright And then slightly bluish white light That's kind of cool whites can you can dim and do different color temperatures? I think with they just can't turn red It's yeah, they're yeah red life x ones. I believe can So you've got a couple options. All right, cool That charlie dude also weighed in and said I have three or four different brands of wi-fi bulbs in my house My fave is the kree bulb. They're cheap. They don't randomly disconnect I've found that the g bulbs do that They have a good range and work with our wink to hub I heard they work directly with echo as well, but I haven't tried that yet Yeah, we got we got a good little experiment going on here So I'm just not involved in nova cork kree bulbs. Probably are fine All Avengers joke nice We also got mike the police officer writing in with a full description of his thoughts on security systems as a police officer We'll have the full thing in the show notes if you want to read it. It's really good But here's a summary He says he's responded to thousands of residential alarms in his 10 plus years as a cop and can only remember one in all of those 10 years Where the alarm indicated an actual break in he's like they're almost always false alarms He says even if they're real most burglars are gone before police response can happen Anyway, especially since most burglars come in the late morning when people are at work and nobody sees them around He does say that alarms that provide video and audio are more helpful Writing this newer wave of connected cameras essentially lets you be your own monitor and act more quickly when contacting law enforcement No monitoring service as a middleman and provide descriptions to responding officers I own both a ring doorbell and three blink xt cameras He also doesn't put much stock in ring's social networking features And he adds peace of mind is worth whatever you're willing to pay for it And I would never tell someone to not purchase whatever makes them feel safest But I want to know the best burglary deterrent get a dog I can't remember ever working a single residential burglary where the victim owned a dog plus. They're cute. Love you and junk Oh You're speaking my language, sir. Thank you. I feel like Otis would be like hi. Let's make dinner But yeah, uh, don't tell the burglars that Thank you, mike, uh for sharing your insights as a police officer really appreciate that Absolutely. I I I always sort of wondered, you know, I I've never had a alarm system Um, I actually have but I've never like paid for it to be engaged I always wonder like, okay. Well, I would know after the fact that this happened But I mean, are you gonna catch somebody, you know a perp in the middle of their crime?  You're the best and also thanks to scott johnson for being so wonderful scott What's been going on the last week? Well, that's very nice for you to say. Well, there's a lot going on Including we talked about games coming up and we talked about e3 Well, if you want to get a great preview of what's coming at e3 Make sure you check out the mvgb feed from patrick beijon myself. That's the monthly video game briefing at frogpants.com Slash mvgb. It's part of the dts network and really worth your time Especially if you're just a a casual tech minded gamer who likes to follow the industry We cover the big stuff On that show and we got that big preview coming up But of course patrick and I are planning all kinds of e3 coverage as we do every year So keep an eye on that. You can also find me on twitter over there at scott johnson Folks if you are like wait live with it gdi. What's all that? Well, good day internet is a larger version of the show where we talk about a wider range of topics That you can get through our patreon and live with it The recent special was about uh jabra elite earbuds and the future one will be about these light bulbs And you can get that as well by becoming a member at patreon.com slash dts Our email address is feedback at daily tech news show dot com write us tell us how you feel We're also live monday through friday at 4 30 p.m. Eastern 2030 utc Find out more and tell a friend daily tech news show dot com slash live back tomorrow with justin robert young talk to you then This show is part of the frog pants network Get more at frog pants dot com Time to club hopes you have enjoyed this program I also have the wizard of awes book and record What What's that handy is the weird bit is someone just Reading the book So the right the record reads it and then tells you when to turn the page for the wizard of awes Yeah, that's a long book. Why do you have this for real? I know you kind of went and found it before the show because there's no way it was when they reached I know I went and found it during the show because I forgot to go get it before the show Where what where do you like how is this all like in the same room? I'm like, I think it might be right here But no but the wizard of awes like that's a that's a long audio. It's obviously a bridged for the version. Oh, okay. All right I remember having great lines of kansas a little girl named dorthy lived with her aunt m one day He was walking home with a little drug soda. Oh, yeah. Yeah, it's yeah No, I I I do remember back in the day. It was like you'd have little 45s You know and it would ding and then it would tell you when to flip The 45 over, you know, because they couldn't fit the whole thing on one side And there was one that I had I don't know why my parents got it for me, but you know that story the fox and the hound Well, well, it doesn't end well It's a real tragedy of a kid's story And I remember like it was like something where at the end of it, you know, I'd be beside myself sobbing And finally my parents were like, okay, we're not gonna we're not we're not gonna We're not gonna play the fox and the hound anymore It was a snow white or whatever it is. You're you know, the other stuff you're listening to it was as harsh as bambi in the end that Oh Just brutal My old yeller, uh 45 record. There you go. Same idea Where the red fern grows you should get the where where the red fern grows Walking dead Yeah You know the shiny and for kids it's a bridged Little Jackie was all working dope. Yeah. Yeah. All right. Uh, we got titles, uh, google's riveting reading app Uh, still matching when xp in 2019 Also good riveting and writing Uh, just to the translatotron I like all of these. Yeah auto blocking robo calls robo blocking robo calls Uh, put your phone on the moon Bamsam, frisco Bamsam, frisco. No, bam. Well, I remember when I was like it's a Bamsam risco Uh, netflix plays games with expectations. Uh, yeah, I don't To the translatotron sticks out to me, but I could go with any of these I like that one. Yeah Yeah, I like that. I like the old time radio sound of it That'll work And then for good day internet we have one submission on here I'm so fancy Wait, it was Who said who said they were fancy? I think that it was submitted when we were having the uh fancy uh fancy department store Oh, okay. No Montgomery ward right Very fancy. Hmm We could have um chef salad.  I know what's in a chef salad. Why is it called that? Depends on the chef. Can we talk about this recently? I feel like we we kicked this idea I don't think we came here. I don't think I did maybe it was while you're out We were talking about it. It's possible. Yeah, okay I just feel like, you know, that's been a little presumptuous I feel like the idea is whatever the chef had laying around he would chop up and put in a salad Oh, this actually does sound kind of familiar. Maybe we did talk about this. Are you hungry? Well, I can whip you It should be called the everything but the kitchen sink salad then Not the chef's everything and the kitchen sink. So right because sometimes you get a little porcelain in your salads Right. It's good for your teeth. Why does this say moan on this? That of crouton Little gritty today my chef salad I don't know. I just I know a few chefs and it's like It really depends on what like, I mean being a good chef does not mean like, oh, this is the sort of thing that I do it like It's so It's like saying you're a good podcaster. What's like, well, what's the content? What's the content of the salad? Chef salad best podcast Right. Yeah, the one that you'll listen to from start to finish Hey, so you know how um a while ago I we were talking about me using my old sonos speakers to connect to my tv to maybe be a You know, kind of like stereo input and it was somewhat confusing as to how that would work I've tried many options None of them work. However Even though the sonos one unfortunately can not be used directly into my tv the sonos beam can And then my two play threes which are the speakers in question Can be connected to the beam as rare speakers So I actually have I mean it would only be 3.1 surround But it would actually be more surround than I had before because I used to have all three just pointed at me So I think that's what we're gonna do. Yeah, I like that 3.1's not bad Yeah, no not at all and I mean and my living room is not a big room, you know, it's like I don't I don't even need to you know have anything on particularly loud But I love the idea of having stuff behind me I do have issues with calling 3.1 surround because you don't have any rear speakers So it's not really surround. Well, but they would be it would be the beam Oh, you'd be my front speaker and my two plays would be It would be quadrophonic because your beam is a stereo triangular Surround you just need to put it in the van with shag carpeting and cruise cruise the boulevard And I'm Well, because I just feel bad because I'm like these are nice speakers, but they're not smart speakers, you know Like it's like like why doesn't sonos let me use these just passively But I think the beam is that I think that's I think that's the call Yeah, it sounds like Figured if anybody has better idea, let me know, but I think that's what we're going to do I just feedback at daily tech news show dot com I can't get anything fancy until my kids are older and I'm pretty sure they won't drag a speaker on top of them It's my only concern Well, that's a downer I'm sorry. Oh no, I mean just it's one of those things where you just like I want tower speakers instead of like instead of the soundbar I have for my tv, but The tower speakers are relatively heavy things right 40 50 pounds a billion which I mean I got I got rid of my nice Bowers and Wilkins speakers Well, I gave them to a friend who had had just gotten a new house And so I knew that he and his wife could use them, but but yeah, I mean they were they were huge they were beautiful but they were Almost more than I needed and they actually like didn't I mean you would have to have a pretty large wall You know to have like a tv mounted and the speakers Enough on the side of them to make sense and it not look weird, but yeah, I mean they were Extremely heavy Without fail like the hardest thing anytime I moved the movers would be like I just I don't prioritize speaker tech enough. I just don't bother with it And I probably I just feel like I feel like for what I want Everything is just small now like I don't need the big thing even though it looks cool. I don't need it It's just hard to find a very musical base that you can get that you can buy that's like under 1200 bucks Yeah, that's that's but that's like a subwoofer because that's always been my issues like I can get away with like my my debt these speakers I have on my desktop are like These wolf wharfdale 8.1s from 12 years ago. They work pretty well, but they bought them out at 55 Hertz, but I mean are you like going like deep bass like well, that's the thing Typically your bass bass Might kind of get you feel it. He's rumbling it right now No, but I had I had a subwoofer too and like half the time I'd be like too loud Yeah, you know if you want to subwoofer you want it to least go at least to 35 Hertz or lower because Certain instruments tend to bottom out much lower like a like a like a bass or feel this in a bass bass But the thing is you want a larger subwoofer because Volume isn't the same thing as how low it goes or how how well you can hear it If you have a large physically large like a 10 inch subwoofer or larger You can get away with a lower volume on it and you could still hear it Yeah, because he can propagate the way I agree. It's having a sub, you know, if if it works with your setup is always better But um, it can also like Shake your house. Oh, yeah, you know, which is some people want that. I don't really want that I just want a house is a rock and you better bring something to eat because I'm watching Just come on in said We're binging some Netflix show I'm binging the Marvel Cinematic Universe. How many how many of those punches by captain america kick you out of the seat I could do this all day. Yeah, you could do this all day and he says I know You're so awesome captain america Captain america norm, uh, norman All right, norman. Yes, it's got an email from someone named norman. I meant to say roger Wait a minute. Is it because I look like norman from what's his name? No, it's because no You're welcome at all times like norm from cheers. Yeah, not norm not norman jam, but so the heavy set guy that Formed a divot in the bar because I literally got an email from someone named norman and I was looking at it while I was trying to say That's fine. I'm just teasing you. But anyway, uh Uh, how forgot I was gonna ask you What was it about? Oh, did you have time to go see it yet? Have you seen that game yet? Yes. Oh good What's your verdict because I know sometimes it's a fun movie I will I will say it's a fun movie All right If you this is the problem if you think about the movie real hard you start the plot holes Really kind of Get annoying like why don't they do this That's the entire marvel of but that's the thing like if you treat if you treat the marvel cinematic universe as a theme park ride Yeah, go on it to have fun. I mean I treat marvel comics that way too. Well, yeah, well, that's you know, it's It's it's escapism. It's fun. You know, it's not a great movie It's a very fun movie and if you want to like have fun for a weekend like, you know Like for two two and a half hours. It's it's a great way to spend you like enjoying yourself over quality Roger says see this movie. Yeah, exactly Listen, you know, I was miserable, but it was great. It's not really the On the rare occasion when I go to a 7-eleven, I'll get an icy Now I know it's bad for you and generally the sugar wears off too quickly and you get into that Slump when your blood sugar level goes down after being spiked. But while you drink it, it's some it's great Well, Lucy wants to say she's more of a dc gal Oh, really? That girl There's a cinematic universe that took a left turn and just fell into a ravine Do you hear that Lucy? She says I reject I reject your opinion people like that shazam quite a bit Lucy, you know for those on audio And you know, and what's weird is from what I understand shazam is like the exception that proves the rule Yeah, maybe. I mean Wonder Woman was cool. That had some moments Wonder Woman was really good. Yeah I think what my biggest problem with with the the dc cinematic universe is ever since like nolans batman They've all tried to be like this very gritty You know sepia toned universe And it's just like it doesn't feel it doesn't have that fun whimsical aspect Like Like one of the gritty undercurrent for you Well, one of the great things about Iron Man when it's first done is they show the whole process of him building the suit and learning And you laugh along with him as he's like just doing all these like things that you would Possibly do as well. Yeah And folks if you want to laugh along with us as we talk about how we build the show Stick around audio folks. There's more of that to come video folks. Thanks for watching


We're at Base Camp in Frisco, our new clinic. I'm really amazed and impressed by the work that's been done here. Well, this is a state-of-the-art facility, so we have a brand new MRI, which I just look at some of the images coming from the MRI, which are very impressive. The quality of the imaging for patients is the best available in the country right now. The first one in Summit County. One good thing is we're closer to Denver, so truly access to serve our patients from the foothills is going to be really, really optimized. We have some of our patients who will fly into the DIA to the International Airport, can buzz up here in under two hours, be seen and go home and fly back the same day. So we've had that happen quite a bit more here rather than in an unveiled spot. World-class athletes, world-class doctors, a world-class team from the Stubborn Clinic. Yeah, I'm excited. I'm thrilled. Yeah, I'm really jazzed about this spot and our commitment to this part of Central Colorado. And we're committed to provide the community with the best possible care and access to our services, and we're proud to be part of this community.


Hello and welcome to the Grand Line Review, your source for everything one piece. Except for today, because we have reached 18, 19 and 20,000 of you phenomenal subscriber folk, so we are going to engage in a celebratory session of highlighting some more of your best channel comments. Enjoy. And we are going to commence proceedings with some casual madness from Simpleton S-Man. You are now a jellyfish. Thanks, Simpleton. I mean, do you have any idea how difficult it's going to be to edit this video with jellyfish appendages? So you know what, if any of you have any complaints about how late this video was, address them directly to Simpleton S-Man. Moving on, Jaby Basilio has come seeking a favour. Can you feature me in your next channel comment? I just want to say happy birthday to my love Penny. Thanks. And absolutely happy birthday, my love Penny. Although I'm sure it's probably long past by now, once again, blame Simpleton.  These are generally just for a bit of fun, but ProMusicNYC raised an issue in regards to the Kobi 101 video.  And uh, my apologies. I'll try to make the useless de-fack a bit more useful in the future. And now we move to Randy Goko, who believes that the Gomu Gomu no Mi should have been number one on the top five devil fruits list. But this is no normal statement. No, this is a three-carriage thought train. Where is rubber fruit? Double comma. The invincible is rubber. And the OP yummy yummy. But the rubber is the most potential fruit. Maybe this is a Roger fruit. The rubber fruit is the true invincible fruit plus Haki. So in conclusion, rubber is an invincible maybe Roger fruit, but only when plus Haki. Look, I'm not entirely convinced, but sure. So recently I did a review of the episode of Skypeer, a special that attempted to summarize the events of Skypeer in roughly 100 minutes. It was actually less of a review and more of a rant. One which just Gilbert's disapproved of. Disrespectful to Lord Enel. Notice that the El in Lord is capitalized while the Enel is not. Very disrespectful, I think. However, at this stage, the all-powerful God Enel himself actually stepped in to voice his own opinion. Nah, I agree. I deserve a better special. And there you have it, divine proof that the episode of Skypeer was utter garbage. But now I want to introduce you all to a user named DabGuard. DabGuard watched my top five best Okama video, and when Caroline popped up, DabGuard found themselves in a state of confusion. Is Caroline he or she? She's jaw is pretty manly, but he-she seems to have breasts. I don't want to talk about how I noticed it, or maybe they are man boobs. And so as DabGuard embarks on a journey of self-discovery, we are going to turn our attention to a petty complaint from Phil Graham. Why you pronounce the names wrong. And before we all laugh uproariously in Phil's defense, he actually pronounced this sentence perfectly.  But while we're on the topic of pronunciation, Gabriel Paulino had a more specific question for me.  My sincerest apology, Gabriel. I'll try harder to pronounce pecoms like pecoms in the future. For now, let's move to Luis Rosales, who has given me probably the most creative reasoning for not adding a like to my videos that I have ever heard. Great video. I can't give likes since I use it to reproduce music I liked. And while I'm not sure if Luis is using his likes on my video to reproduce his music, I have to say that is one very intriguing practice you have going. But now it's time for the grand line review video criticism of the week, featuring special guest critic Sun Goku. This time around, the victim will be my arc review of Dress Rosa. Sun Goku, what did you think of this particular arc review? This video was too long. Halfway through it, I got hungry, so I left it playing, and went to the kitchen to fix myself a sandwich. But then I found out that I'm out of mayonnaise, so I went to a store. There I saw the most beautiful woman I have ever seen in my whole life, so I said, oh boy, friend, I want the best for her, and I won't bother her anymore, but we kept in touch and we became friends, and we broke up over my crush on Dress. I still think she was the most happy with the friendship I developed over the time, well, besides I am quite happy with the friendship I developed with her, my girlfriend wants to live some other life without dating her, and she gave me the same advice I gave her, I have only one bed, so you know what that means. She took the bed and I slept on the couch, she stirred and woke up, she asked what side, I told her you know the first time I saw you, I was watching you. So we opened the drawer, and lo and behold, there's my phone, and this video still has two minutes of playtime on it. Thank you for that extraordinarily in-depth review of my review. Son Goku, I guess it was kind of long. Criticism accepted, but I'm afraid that it is now time to get down to business. Last time you all posed a very important question from Robin D Joker, and that was, how did Frank G feel when Robin twisted his balls? And well, Robin, not the Robin who twisted Frank G's balls, at least not to my knowledge, who knows what Robin does in their private life, but in any case, we have our answers. First up, we have Sean Tell Benjamin making the case for the affirmative. Frank Geely, he felt great, and she wasn't the only one who insisted that this was a positive experience, as we also have Shiny Shuckle. When Frankie's balls got twisted, he felt as good as I did when this comment made it into Best Channel Comments 18. Alright, so he felt pretty underwhelmed then. Yeah, got it. But then again, we have Menograph Mance, who would like to very accurately describe this feeling. My answer to the comment would be, with his nerve endings. In a sensitive area like your nuts, they're rururur, a lot of nerves.  Depending on the sensation, different parts of your brain will be activated to counter or enhance the sensation. In this case, I think the sensation is classified as an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage, most commonly known as pain. And wow, that was a lot to take in, but never fear because we have a simplified version of that answer from Tristan Bruton. Frank G equals much pain from man fruit. But to round everything off, I believe we have official word regarding the matter from Wappool. I am Frank G, and I can say it was not a nice experience. So with that, we are going to call this inquiry a satisfactorily resolved, and move on to our next curious question, and there's a bit of context to this one. In one of the OG best comment specials, we had this question from that one Asian guy, which pretty much began this whole question segment.  Well today, we are going to revisit that category, but from a different perspective.  So I very much look forward to your answers to that. But that pretty much does it for this edition of the best channel comments. If you enjoyed this video, then please feel free to like, favorite or subscribe. And if you are in any way inclined to support this independent channel, then please do feel free to check out my Patreon, Discord server or Twitter, the links to which are in the handy description below. This has been the Grand Line Review, and I'll see you next time.


We all hear about fantastic advances in technology and new discoveries and new therapeutics for cancer and that's great but as we stand today you know many countries in the developing world barely have basic treatment. Everybody has the right to have the best chance for a cure for cancer and it should not be an accident of geography. Unfortunately for those who are diagnosed very lately the treatment is very costly and for many poor this is unaffordable. If the governments, if the donor community, if the international organizations who are dealing with cancer diseases, if they cooperate, if they work together they can help the cancer patients. From my point of view the PAC team has done a wonderful job of getting the ball rolling so to speak making sure that cancer control is part of the agenda of the work and that the low middle resource countries have been targeted in terms of attention.


Manutrition is a major problem that contributes to more than one-third of all child deaths worldwide, with poverty being the primary cause. The vicious cycle of poverty, re-disease, and illness exacerbates this issue. Undernourished children start life at mentally suboptimal levels, posing a serious developmental threat. Lack of education among women, particularly in breastfeeding and healthy child nutrition practices, also contributes to the problem. Adverse climatic conditions such as droughts, poor soils, and deforestation have played significant roles. Sociocultural barriers, with female children being the most affected, are also major hindrances. Corruption and lack of government interest and investment must be addressed to solve this issue. A multisectorial approach is necessary, including improvement in government policy, fighting against corruption, adopting a horizontal approach at the community level, and considering sociocultural peculiarities of each community for nutrition health promotion programs. Genetically modified foods could also be a solution to increase food production and survive adverse climatic conditions. This article was authored by Lutua Engelbert Bain, Pascal Kamawa and Jaya Geraldine, one others. We are article.tv, links in the description below.