1 minute pass 2 let me get started. So, if you can keep your murmurs down and allow me to start. So, those who were there last Friday in the class we were discussing perspective views using I would say a 2 station point method right. So, that is a generic method that allows us to draw a single point perspective, 2 point perspective and 3 point perspective maybe I will wait all right. So, this word is. So, if you do not allow me to start now if you do not permit me to start now our class is going to get spilled over maybe till about 3 15 3 30 because I am going to be introducing a new topic to you and it looks like I may have to do a little bit of explaining. So, if you allow me to start now I will start I will have to talk a little about perspective views and then I will switch on to space geometry all right good wonderful. So, for those who were there last Friday I had introduced what I call a 2 station point method that allows you to draw perspective of any kind 1 point 2 point 3 point depending on how you place your object rather how you place your top view with respect to the picture plane. So, if you have your top view like. So, you will get a single point perspective if you rotate your top view about an axis that is perpendicular to the screen you will get a 2 point perspective and further if you rotate your top view in such a way that none of the edges of the top view or none of the edges in top view are parallel to the picture plane you will get a 3 point perspective. The beauty of this method was that you did not have to specify any vanishing point. So, I was working on this example and we had reached up to this point where I was trying to figure if all the edges of mine they were converging to 3 different points or none. And then you guys said well the first 2 points the first 2 vanishing points they are not lying on the horizon line and that made me doubt myself. And I immediately went on a defensive and I said well I may have made a mistake and help me try to figure my mistake. And we are searching for answers and it looks like I have found an answer and I say that well the only mistake that I was making was I was probably not drawing these lines accurately. So, these green lines now are much more accurate and they allow me to see that these green lines they tend to vanish at 3 different points. I will tell you that they are indeed accurate and the top 2 vanishing points they need not lie on the horizon line I will tell you about that. So, I am going to be switching to a new slide and what you will notice is that I will retain these 3 vanishing points. And I will try to justify that they are indeed the positions that we will get when we are drawing a 3 point perspective here we go you see those 3 dots you do yes or no come on good. Now, this is what I will do I will try to verify these vanishing points I am going to go a little fast. So, try to follow me. So, this is my x axis of the object this is my y axis of the object the vertical is my z axis of the object this is in the top view and the corresponding station point where I am standing the position of the viewer is here SPT. Now, what I do is I look along the x axis at an object at infinity that would hit the picture plane. Likewise, I look at an object at infinity along the y direction and the z direction these 3 blue lines they are going to be hitting the picture plane and they are going to be releasing the respective verticals right. So, on these verticals I expect my vanishing points to line fine with me with me good I will do the same thing with my profile view this is what what axis are these x and y and this would be my z axis I take SPP the station point in the profile view I draw a line parallel to the x y axis and hit the picture plane over here over here and I draw a line parallel to the z axis and hit my picture plane over here from here I am going to be releasing what the horizontal projections right once I do that I realized that my vanishing points are essentially the intersection points between the respective vertical projections and the horizontal projections convinced convinced. So, I did not make a mistake last time now I solved another example and you would see those slides on my web page. So, in this example I took my picture plane to be passing through vertex a not vertex e, but vertex a both in the top view and in the profile view here what I got was this perspective the dashed lines are behind they would not be visible, but they are there for me to verify the vanishing points I start drawing these lines they tend to converge to three different locations. And if I do the same exercise if I retain these positions of vanishing points draw my x axis y axis z axis in the top view using SPT draw three lines parallel to the three respective axes allow them to hit the picture plane here get the verticals. And then using SPP the station point in the profile view draw raise parallel to these three axes here x y and z. And I release the horizontal projections from there I tend to see that my vanishing points are you know the intersections between the vertical projections and the horizontal projections. So, you said that you did not have the proof, but now we have one. So, it works let me tell you I have a wonderful team I am very fortunate to have a wonderful team of tutors and TAs and I am sure you are benefiting a lot in their presence and with the knowledge. So, this is something that I did not think about I did not analyze about. So, for sure help me think about this and so one whole very elegant way of getting a perspective the only problem is that you have to figure how to draw the true top and profile views that is the only problem that involves two rotations of the object. And once you have that perspective is straight forward. So, this what the bottom line was where we all got stuck Friday the top two vanishing points need not be on the horizon line or the picture plane yeah Ayush. So, Ayush sent me a link on YouTube teaching me how to draw a circle in perspective. So, I will let him teach you guys oh we cannot switch the laptop I have the ok. So, we will probably do that at the end of the class maybe, but perhaps what you can do is you can use this animation and explain how to draw a circle in perspective yeah because that would involve switching time I have the slides yeah wait I have to give you the mic what do you have this for I do not have this it is not like it is not mine suppose we have the right pattern yeah get the animation first. What I will say 8 is that I will take the hominids yeah ok. Then I will join the two diagonals and the two lines which are actually the mean diagonal this diagonal and this diagonal this line was supposed to this and this line was supposed to. So, what I have is this is the hominids where these are the two diagonal and these are the diagonal diagonal. Then I will join this to this point this to this point this to this point and this to this point this is hominid diagonal and I can I will then say that the point of which is this one this point this point and suppose this is the and same of all the other squares. So, actually speaking actually speaking what you have are two methods right in front of you to draw a perspective and to draw a circle in perspective ok method one is what you see on screen right. So, you have the bounding circle enclosing bounding box including a enclosing a circle you have 8 points on the circle ok. So, corresponding to this bounding box you draw this box in perspective you locate these points corresponding to these great points here the first method you draw these two diagonals and then locate these red dots on those diagonals. Now, corresponding diagonals in perspective would be these two diagonals joining the opposite vertices now you would know that this would be in true length you take this distance from here to here you take this distance from here to here measure these two distances here project array starting from here up to the vanishing point and then another one starting from here up to the vanishing point. These two rays are going to be intersecting the two diagonals at four red points that is method number one method number two is what Ayush proposed instead of doing that instead of having these join these four points you will be making a diamond and then you would have this square this square this square this square you will have a diamond here here and here and then what would you do Ayush you would have a midpoint you would have a midpoint of this. So, you would have a midpoint of this midpoint of this midpoint of this midpoint of this you will get these four points and then draw another circle yeah so the second method of course is probably not exact, but it is relatively faster than this method this method happens to be a little more precise yeah ok. So, straighten your back if you have seat belts buckle yourself and get ready to sleep a new topic space geometry one request that I would want to make is I will try to explain this as best as I can, but just in case if I am not clear enough to raise your hand and if I cannot see your hand do get up if I still cannot see you use the chair stand up on the chair raise both hands and say sir stop I did not understand and I will be happy to explain that to you.  So, which view is this which view would this give you front view which view would this give you top view wonderful the front view the top view the front view will be on a vertical plane. So, I would call the bottom plane as the vertical plane the top view will be on the horizontal plane and I will call that as the horizontal plane. So, there will be a switch in notations in terminology that you need to understand. So, this is the front view or what plane top view and what plane good imagine that I have a line whose projection in the top view will be is a horizontal line. And the same line in three dimensions whose projection in the front view or vertical plane is an inclined line a little bit about coordinate geometry very simple let us say this is x 1 z 1 let us say this is x 2 z 2 the coordinates of this vertex x 1 z 1 coordinates of this vertex x 2 z 2 in the horizontal plane let us say the coordinates are x 1 y 1 and x 2 y 2 what would be the length rather the true length of this line whose projections are given there this delta x the whole square plus delta y the whole square plus delta z the whole square square of that. Now, since the projection of this line in the top view is horizontal y 1 is equal to y 2 and if I set this to 0 my true length will be delta x the whole square plus delta y the whole square right sorry delta z the whole square delta z the whole square with me alright. Now, do you see the projection of a line where you can find this length do you see the projection of the line where you can find this length on screen yes which one is it the front view this one here x 1 minus x to the whole square plus z 1 minus z to the whole square this is in true length alright. So, if this is not clear I have this pointer here it is oriented in some way in space what you see is the front view of this what you see is the front view of this in the top view I would see a horizontal projection of this line this is what these two projections are with me good. So, this is just for your understanding in your laboratory exercises you will not be needing coordinate geometry you will essentially be working with geometry. So, this is in true length and I label this length as t l true length another scenario x z plane the front plane or the vertical plane and x y plane the top view or horizontal plane this time in the horizontal plane I have a line or the projection of a line inclined differently it is not horizontal and in the front view that projection is horizontal coordinates x 1 z 1 x 2 z 2 x 1 y 1 and x 2 y 2 the x s remain the same the z's and the y's they get changed. Now, what do you expect the true length of line to be in this case in the frontal view on the vertical plane z 1 is z 2 look at that equation of yours from coordinate geometry z 1 minus z 2 the whole square is 0. So, your true length is delta x the whole square plus delta y the whole square which actually you can get from here. So, this is t l now these two examples should tell you something if I have the projection of a line which is horizontal either in the front plane in the vertical plane front view or it is horizontal in the horizontal plane or the top view I would be getting the true length of that line in the other view do I make sense do I make sense good. Now, imagine this line space and this line is oriented in such a way that you get the projection which is not horizontal in the front plane in the front view vertical plane and it is not horizontal also in the top view the horizontal plane what you do in that case how do you find the true length how do you find the true length you can use the experience from the two previous examples. You can make more of the projections horizontal if you do that the other projection will give you the true length of that line. So, what we have is the method of rotation for that let us say you rotate the projection in the horizontal plane of top view by some angle that rotation is about what axis the z axis this axis over here.  So, that you can get the true length of a line over here right now what happens after that what happens to the corresponding projection of the line here any idea let me get back let us say you are rotating the line about this point you are rotating the line about this point about the z axis. So, this point remains fixed let us go up what happens to the x comma y comma z coordinates of this point with the x coordinate change with the y coordinate change with the z coordinate change the z coordinate will not change come back to this view the z coordinate of this point could not change. So, you can expect the z coordinate to be lying somewhere on the horizontal green line true true and you already have the position of this point in the top view use this projection get this point. So, if you have rotated the line. So, that this projection happens to be horizontal this would give you what the length of the red line will be the same the length. So, if you are rotating this line the length does not change. So, this green line here would represent what the true length of this line in three dimensions do you agree do you agree who does not yeah. So, remember that these two black lines these are projections number one. So, if you are rotating the line about the z axis its projection will also get rotated what is your question yeah in the top view it is not getting rotated about the y axis perhaps let me let me come back to the other example let me come to the other example that would help you understand this better this is ok right this is ok the same example. Now, let us say you have this line now you see the projection of this line in the front view now I am going to rotate this projection in such a way that it becomes horizontal I am going to rotate this in such a way that this becomes horizontal this rotation is about what axis the y axis now of course, this length would not change this length what you see would not change right what would happen to the y coordinate here no change I am rotating the line about this point. So, this point remains fixed in space the y the y coordinate of this line does not change I already have this point located over here I take its projection this word give me the true length of a line. Now, what do I essentially mean by true length let us say I have this line and what you see is this line in this plane yeah now if I rotate this line. So, that this line becomes parallel to the plane of sight it is only then that you are going to be getting the true length of this line not otherwise right once again if I make this line parallel to the plane to the vertical plane it is only then you are going to be getting the true length of that line yeah what is that I cannot hear you yeah we are using both planes for a view in that example the line becomes parallel to the horizontal plane that is the reason why you get the true length of that line the horizontal plane in the previous example the line becomes parallel to the front plane that is the reason why I get the line in true length in the front plane you know you guys are tired I guess from the galaxy thing. So, I would suggest that you take out your notebooks and pens and start scribbling because this is not very difficult. So, with that you will also follow what I say a lot better and then I will keep you active and then I will keep me active ok. So, is this method of rotation clear to you all is this clear should I go back and go through these two examples again yes sir no sir everybody with me I will go back alright.  Now, the trick is very simple you want to see one of the projections either in the front view or the top view to be horizontal if you see that the other projection will ensure that your three dimensional line is parallel to the plane and therefore, you will be getting the true length of the line fine alright in this example rotate the top projection. So, that it becomes horizontal when you see that you are rotating this line about the z axis. So, the z coordinate of this point does not change you are rotating the entire line about this point. So, this point remains fixed in space if the z axis here does not change sorry the z coordinate does not change then this point has to lie on the horizontal if it lies on the horizontal you already have this point located in the top drop a projection you get the new point. And therefore, you get your line parallel to this vertical plane and therefore, in true length fine alright. Let us do the same thing, but reverse the same example now what I would want to do is I want to see this projection to be horizontal. So, I would rotate this projection about this point and about the y axis the length of this projection does not change. Now, if I am rotating this line about the y axis the y coordinate of this point does not change. So, this point has to lie on this horizontal fine and then I already have this point located over here I take the projection up I locate that point this line now becomes parallel to the horizontal plane straight forward this is going to be very boring or could be interesting depending on how you take it. So, given these two projections of a line oriented arbitrarily in three dimensional space let me try to locate the actual line in space. So, I have this box stay with me stay with this is my what was this front view or vertical plane that is my top view or the horizontal plane. Let me get this blue line let me work with the horizontal plane first and mark it over here little blue line mark it over there this length is the same as this length. So, this blue line over there represents this guy with me with me alright let us do the same exercise with the vertical plane the green line mark it there second green line mark it there and this green line is actually this guy here you got a three dimensional box you got two projections is it possible for you to look at the actual line possibly like this like this do you all agree that this is the actual line alright. So, let us say my method of rotation is boring it is not good enough how do I get the true length of this line how do I get the true length of this line the only way I can get the true length of this line is to make sure that I am visualizing that line from a plane which is parallel to the line not otherwise the plane has to be parallel to this line fine. So, I have to figure out that plane first of course that black line will be in true length fine. Now, imagine that I have a plane that contains the blue line on top the blue projection imagine that I have this plane here that contains that blue projection now my question is very simple would the actual three dimensional line which is the black line within that box would that line be parallel to this plane or no rather let me rephrase would that black line actually lie on that plane do you all agree. So, if I view that line from that from that plane dotted plane will I be getting the true length of the line yeah good you all agree it does not really matter where I locate that plane space. So, long as that plane is parallel to itself. So, instead of using that dotted plane perhaps I can shift that plane forward or backward. So, long as I ensure that the plane is parallel fine all right now what I do is I drop verticals from the corresponding projections on to that plane. So, these red verticals from this projection which is over here on to the plane and I can shift that black line to actually lie on this plane right fine all right I want you guys to be attentive here I want you guys to follow this carefully this is a hinge line that separates what from what the horizontal plane from the vertical plane good what I would want to do is once I have located this plane in some way and this plane is inclined to both the vertical plane and the horizontal plane. What I would want to do is I would imagine that there is a plane here and there is a hinge line between say the horizontal plane and this plane. And just as what I do in case of orthographic views I flip this what I call the auxiliary plane up. So, this red plane is the auxiliary plane here. So, this is what I do and if I flip it up and if I have that red line contained on that plane this one I would be able to get the true length all right. Let me go back and explain this again this is for you and good. So, this example here I got the projections of a three dimensional line on the vertical plane on the horizontal plane I try to locate the actual three dimensional line within a three dimensional box. So, what I do is I first draw the projection or I first draw that projection on the horizontal plane I draw the corresponding projection on the vertical plane. And then I extend those projections and I get the actual three dimensional line. And then what my proposal is or what my proposition is that if I draw a plane which passes through that blue line on top I would be able to capture the actual three dimensional line which is the black line within that plane and that black line of course is true line therefore, it would be having the true length. So, I would be able to capture. So, if I let if I draw a plane that passes to this blue projection which is this one here I capture this black line the actual three dimensional object on that plane. And it does not really matter if the plane is there or if it shifted by some amount I can always shift my black line and ensure that it still lies on that plane. And all I need to do is process what I call this new plane as the auxiliary plane in such a way that I can see the true length of the line. So, the first thing I would do is I would identify two hinge lines you already know one of them the purple one is the new one. Now, this is quite tedious this is quite tedious I would want to work with this figure over here and I want your attention. So, this figure I have it on the left for reference follow the color codes the brown hinge line is this one do you agree. Now, notice that this purple hinge line is parallel to the projection of that three dimensional line in the top view notice that do you agree good. Now, of course the projections are going to be perpendicular to the hinge lines wherever they are right. So, I draw projections from this projection of the line perpendicular to this purple hinge line fine all with me so far. Now, look at this line here look at this distance here this distance is of this point from this brown hinge line. So, this distance here what I would do is I would take the same distance measure from this point of the hinge line and get this point look at that small distance I would stay on this projection line and take the same distance from here to here and I will join these guys. And then I will say that this is the true length of my three dimensional line do you agree or you are lost good back again. So, far so good here so far so good here. So, you see I have two hinge lines one is the brown hinge line and the other one is the purple hinge line the brown hinge line is relating the front view and the top view the purple hinge line is relating the horizontal plane here and the red plane the auxiliary plane. So, I draw this purple line here. So, go back to your understanding about orthographic views. So, what you do here.  Now, imagine that you have your top view here and you have your auxiliary plane at some inclination to this like this yeah we are doing essentially the same thing we are flipping this guy over in relation to the horizontal plane we are flipping this guy over we are doing exactly same thing yeah. Now, look at these green lines and look at these green lines these green lines they measure the distance of this point from this brown hinge line. And they measure the distance of this point from this brown hinge line. So, far so good so far so good. So, these are my corresponding green lines fine fine now go back to your three dimensional box here and try to identify and try to verify if this distance is the same as this distance from the purple hinge line is it is it likewise for this try to verify if this distance is the same as this distance from the purple hinge line it is it is or not which is what I do here. So, what I have done is I have drawn an auxiliary plane and I have related that auxiliary plane to the horizontal plane. So, I have this purple hinge line here and I have taken this distance and this distance and measured this and this to be the same of course, the projections have to be perpendicular to the hinge lines. So, these great projections are perpendicular to the purple hinge line and if I flip that auxiliary plane over that auxiliary plane is going to be containing the two three dimensional line and it is going to be therefore, in true length you agree. So, a little bit of practice and you will be you know I can only imagine I can only imagine how you are trained in close coaching classes. So, this is that version of it the instructor pardon me if I am wrong, but the instructor in one of your coaching classes will say well you know what forget about this it is too tedious you do not want to understand that you do not want to waste time understanding that this is a quicker version you have these two views all right you have this hinge line yes or no good. Step number one is that true no whatever I am just enacting draw a hinge line which is parallel to the projection in the top view step number one. So, you have this hinge line it could be here it could be here does not matter fine step number two make projections perpendicular to this to this hinge line from both these points step number three measure this distance and mark a point on this projection with the same distance as this number four measure this distance mark this point over here on this projection line with the same distance step number five yeah step number five yeah you can go no stay back no stay back man yeah.  So, if you do not draw this line and if you take projections directly from here this is a very simple example, but in more complex examples you are going to be needing this view not once not twice, but for a few times when you need this view you do not want to lose this projection if you lose that you are confused two more minutes and I will let you go sleep and get ready for galaxy in the evening. I can follow the same five steps I can follow the same five steps with reference to the vertical plane not from the horizontal plane, but with reference to the vertical plane this is how well I have already done that yeah fine maybe I will yeah it does not really matter where you position this purple line you can position it anywhere you will still be getting the same two length of a line. So, this is one quick example. So, the purple line is closer now to the projection in the horizontal plane the same exercise five steps you can get the two length and if you compare with the line in two length from the previous example this was this. So, in fact these lines are going to be parallel I can do the same thing in reference to the vertical plane of the front view nothing changes step one step one no no yes sir step one what is step one draw a hinge line parallel to the projection in the vertical plane step two draw projection lines stay with me stay with me stay with me step number three measure that distance and mark that distance over here step number four measure this distance and you are going to be measuring these distance distances from the hinge line mark that distance over here you got two points join these two points you get a line which is going to be parallel to the auxiliary plane and therefore, it is going to be two length. So, this is a three dimensional line which is parallel to the auxiliary plane and therefore, in two length.


It's day eight of the 50th Street inaugural tour. I spent the afternoon with Skip Elsheimer at A.V. Yeeks, where we talked about his massive film preservation project and he showed me how he digitizes home movies. A complete series of videos and interviews will come later this month after the tour is over. Meanwhile, follow 50th Street for tour updates every day.


Zamo se z tem saj. Druga tebe. Prvom nrolo poločenjo, svoje organizacije din moj, zato je bil vse navršen za posločenje, kom, ki sem tko nadal... Pri lasti se izgolejo, očas ili je mi brel miles, in tebe ga peničo izgole s prolastv. ... v zelojnjih roli sketchesin, k dév prvストosti roli tisti. Zelojno v到on niči vzeloj svetnja, da se vzpečila vsega načinje, in zelo vzpečila vzpečila. Prepoče sem začala, da sem se različila, in kako sem prišljala, nekaj je prišljala, ki ješlje, prišljala je svega, zelo vsega, ko je vsega, in ki je vsega, je vsega, da je počak, počak, Max B, Jim Boyang, Michael Czakowski, Mateo Paoluzzi. Vespečne včešče je tudi vključila z grubami Georgeo Schitta in Roberto Cervino v Milanoj universitičnih. Sela je tudi nekaj komplek, ali po pravih tukovosti, zelo sem zelo, da se zelo načinje, da se zelo načinje, z zvajenjem kontrakciju in kotljenje, z ko je stajnila in vzpravil je instihljevosti, ki je evočno se vzpravil s kamikalim energijem in začeli s mechanicali vzpravili. Zeločijo je je zeločne vzpe, zeločijo 10 v mikro per hour, nekakšno mladke, danes način, da je prijevak, kako je materija, nekako lepe. V njimeljih tih, njimeljih vzpravil je, način, peterinjelj tih, kajest, kajest, general, jone substrajt in levin, tisy sels move kolektivli in naoji, jih zame moving of a wood, wood deli in gas, se jaz iz kod, da, where the epithelial cells march coherent li, to fill in the wound in the tissue? And of course another great example is one that Tamač, we check already showed this morning in a different system. This movie, noop, okay. What happened? This movie down, nah, it doesn't work. Tukaj da je v vse, je... Hmm, pa moj mous. Okay. Ah, bojte, da je tukaj vse. Okay, tukaj tukaj na vse je našelj več, in je tukaj izvršenje tukaj. In pri vse, svej se dobro vse vse da se prišli vse povedi za dobro, a pri vse, se prišli za vse, in počkosti, način, kdo lahko še pripelj, bi ide se prišli, da bi je zdivati ljudje, ki so rečen, da so počkoli se. Na Slovene je vzreša, da še počkoli je uПa pa začnučen tอยosti, ki te imaš i zo bote. Neči se je počkoli, da bane počkoli je, če se tijto vse tijto vse tijne začne. Vse bane dovolil svu prej nekaj delatim, in mi je, ki bo, da bo zelo načkoli, ki so počkoli počkoli dopozibiti tijto vse tijne, and how they are determined by the properties of individual cells. Let me show you a couple of other examples before I go discussing. I'm a theorist, so I will describe you some models, but I want to show you a couple of other examples from experiments. So here is another epithelial tissue. These are actually cells from the lung from the group of Jeff Redberg at the Harvard Medical School. And what it shows is that as time goes on, since day three, day six and day ten, this tissue actually gems. Cells over here are moving as they would in a fluid, but eventually after about a week, they gem into solid light behavior, and this is highlighted at the bottom where you can see the individual velocities that are tracked by particle image velocimetry from this tissue. So cell layers can gem over time, and as you can see, this is an example of what's called the confluent tissue.  Something else is driving the gemming. And in these other examples, these are actually breast cells, again a confluent layer of breast cell. To the left is essentially gemmed, you don't see a lot of motion, but then when you add a particular protein called RAB5A, which is associated with endocytosis, essentially what happens is that the tissue becomes a fluid and exhibits these large scale coherent flow-like motions. These are actually experiments from the group of George Ashita at the University of Milano. So cells can, cell layers, tissues, can tune themselves between solid light and liquid light states. Now, we are familiar with this kind of behavior in active systems, meaning systems composed of entities that are just like cells, are active and motile. And in fact we know that we can actually go from sort of an active gas of particles moving around in random direction to something like a flocking active fluid as we increase density. These are experiments back by some time ago in skin cells, and as you increase the density, you see that you go to essentially a packed system and the velocity vector show at the bottom becomes smaller and smaller, so the system is slowing down, there is gemming due to crowding. But in this confluent tissue, as I already said, packing fraction is one, cells cover the plane, so the collective migration and the changes between fluid light processes, some mechanical feedback, cell-cell interaction, and actually cell shape changes occur in the tissue, certainly not by density. And so we need a new type of model as compared to the agent-based or particle-based type models that many of us have been using to describe flocking or collective motion. So what I want to do today is essentially tell you about some models, the models that have been used quite a bit in developmental biology to describe this kind of system, but by assuming them to be in equilibrium with active matter models that is adding motility essentially to these models in developmental biology to try to quantify the materials properties of tissues. And I will show you essentially two things. First of all, I'll introduce a model that actually shows a liquid-solid transition tuned by density, by cell motility and by cellular shape. And then I will add some kind of alignment interaction and show how that can drive flocking and coherent motion of these cell monolayers. And the parting gray is actually, I just want to advertise it, we recently actually developed a continuum model of the kind of system I will show, the kind of model I will show you in a minute, which is sort of like a toner-to flocking type model, but instead of coupling to density, couples to an order parameter field that describes cellular shape. So, there is a well-known model in developmental biology known as the vertex model, which is a model mesoscopic scale model of a confluent tissue. Again, here is my tissue, if you look from the top, it looks like a foam, what you see in white are the cell boundaries. Of course the cells have a finite thickness, but we are going to make it completely two-dimensional model where your cell monolayer is in the plane, is a translation of the plane with polygons. The degrees of freedom in the original vertex model are the vertices of the polygon, but in my model there will actually be the area and perimeter of the polygon, so each polygon is a cell. And people usually write down an energy for such a tissue, which incorporates, of course, some physics. There is a term where cells tend to adjust their area to a target value, and this describes the fact that the layer itself is incompressible, but cells therefore can change the area in their two-dimensional model by adjusting the height, that's what this term is supposed to describe. There is a term here that describes proportional to the square of the perimeter, that describes bulk contractility. There is essentially a network, a polymer network, which tends to contract due to the actual motor protein, and that is tends to affect the perimeter and this term is essentially a line tension proportional to the perimeter and the line tension itself has a sign physically, the line tension, that is how big the perimeter is, will be determined by interplay between cell-cell adhesion that tends to make the perimeter bigger and contractility of the cell that tends to make the perimeter smaller. I've chosen a minus sign in a regime where actually adhesion wins. The perimeter tends to get bigger because that's the interesting regime for our purposes. I can use the square root of the area A0 for my units of length and complete the square in the perimeter and rewrite it for my energy as quadratic in both area and perimeter and when I do that, the model contains two dimensionless parameters. This is essentially the ratio of the coupling constants Kp and Ka and I will really not vary that very much but the key parameter is the ratio of the perimeter the target perimeter to the square root of the target area and the target perimeter of course will depend on the line tension. So this that I will call target cell shape is the measure of how anisotropic the cell is for a circle this will be a number of about I think almost 3 for a pentagon if a regular pentagon is 3.81 for an hexagon is 3.72 the more anisotropic or elongated the shape gets the larger this number is. So that's the model that has been used in biology to actually relate the cell configurations to the forces that are present on the edges of the network in equilibrium and what people generally do is that they minimize this energy with respect to the position of the vertices and the cellular rearrangements the main type of cellular rearrangements that occurs in these tissues are known as T1 transitions these are kind of rearrangements that can turn your tissue into a fluid because they allow for neighbor exchanges you go from a situation where the two white cells are neighbors to a situation where the two cells are neighbors and to do that you have to overcome an energy barrier when my colleague Lisa Manny did a few years ago she actually studied the statistics of these energy barriers and she was able to show by minimizing energy that the mean energy barrier if you plot it as a function of this target shape parameter actually vanishes above a value about 3.81 which is close to the value for pentagons suggesting that above this value the system is a liquid because this transition can occur with no energy cost and below this value is sort of a solid so what we did then was to combine this model combine this vertex model energy with active particle dynamics construct a model that we call self-propelled Voronoi model that describes now a confluent tissue where the tissue is now we actually use really a Voronoi tessellation of the plane and we assign also to each cell a motility which is in the direction which is of fixed magnitude and is subject to orientation and noise so the dynamics of the Voronoi cells of the centroid of the Voronoi cells is controlled by self-propulsion with direction randomized by rotation and noise and forces which are obtained from this tissue energy I showed you before and the really interesting important thing is that these forces are multicellular you cannot write them as pairwise additive and they are not just among nearest neighbors so this is a more complex type of interaction the particle type interaction usually used in the agent based model so if you simulate this model and calculate say the mean square displacement of these cells or polygons as a function of time for increasing value of the shape parameter p0 what you find is that for large p0 the system is a fluid mean square displacement is linear in long time and for small value of p0 it becomes solid like the mean square displacement doesn't grow in fact more precisely you can define a diffusivity as an order parameter and it will go to zero at the value of p0 that now depends is close to 3.81 and it depends on the motility of the cell the cell propulsion speed as well as the time scale for the rotational noise that determines how persistent the dynamics is and in fact you can construct a phase diagram this axis is the cell motility v0 this axis is the target shape index and you find the transition using this diffusion coefficient as your let's call it order parameter between the solid and the fluid the solid have a small p0 so they are effectively rather round and regular and they don't stray away they are caged these are the path of the cells and in the fluid they are more elongated although it's hard to see by eye and they move around the system like a fluid this parameter p0 really is the interplay as determined by the tension which remember is determined in turn by the interplay between cell, cell adhesion and cortical tension so surprisingly the fluid occurs in the regime of large adhesion that's because tells like to create more adhesion by extending actually their boundaries and well that's just to image the fluid and solid like behavior we just call it the few cells just to make a sort of a nice movie here the really interesting thing is that you can actually define actual order parameter for the transition that is if you actually measure the mean shape of the cell so that is take the ratio of the perimeter of each cell to the square root of an area of each cell what you find is that in the solid so this is different from the target shape parameter which is the parameter of the model in the solid this is locked to the value 3.81 because essentially in a regime where area and perimeter are incompatible and in the liquid it just grows linearly so you have a continuous phase transition from the point of view of the structural order parameter between solid and liquid behavior and the reason this is interesting is because it means that prediction here that can actually be validated in experiments is that you can actually determine whether the tissue is a fluid or a solid by measuring the mean cell shape and in fact if you take this q and set it equal to 3.81 you produce a line in the phase diagram that pretty much coincides with the place where the effective diffusion constant goes to zero and in fact a couple of groups have tested this prediction by measuring cell shape these are again the experiments by Fredberg at Harvard and although well this biology so there are big error bars but as you can see as time goes on and the tissue jams the mean cell shape seems to approach this value of 3.81 in the system and similar results has been obtained in breast cell by the group of George Oshita so that's so what I've shown you here is that we have a model for a tissue that includes motility and cellular shape rearrangements and cellular shape changes and produce an active solid liquid transition tuned by motility and cell shape it doesn't quite yet get to this idea of how do cells coordinate their motion but clearly it's important to know the nature of the material to know how cells or whether cells can actually move through it next I'm gonna tell you about sort of adding alignment to the model to produce actually a system that can also actually move in a correlated way that is flock and in other words I want to ask the question how now to cell actually correlate their motion as seen here in this protrusion which is a finger like protrusion again in a wound healing assay so well one simple way to do it is to simply add an alignment interaction to our model that is modify the angle of dynamics here not just now rotational noise but in addition we have an alignment of strand J each cell tends to align its direction of motility or polarization with the direction essentially of the mean force which is internally essentially the same as the velocity of the cell and so now we have a new parameter in addition to our cell shape parameter sorry I called it P0 before S0 and P0 are the same thing we have the alignment strength and then we are gonna keep the motility and the persistence of the dynamics we are gonna keep those fixed what you find is that if you now try to make a and this is just a pictorial phase diagram I'll show you a quantitative phase diagram in a minute this is in the plane of the strand J of alignment interaction and that shape anisotropy parameter so for low alignment interaction we have the same two states we had before a solid state and the group of cells has only been colored to show you whether the system is a liquid or a solid so in the solid they stay together in the liquid they kind of fall apart but the mean velocity in these two states remains zero for higher alignment interaction of course the system flux it has a zero mean velocity in the solid this blob of cell just moves along without much deformation in the liquid it gets deformed so quite fall apart as strongly as they do in the absence of alignment and in fact if you look at the system a little bit more closely what is now plotted here are the cellular paths in the rest frame that is in the frame that is moving along at the mean velocity the red bar denotes the mean direction of motion and as you see this flocking liquid seems to have quite a bit of order most of the displacement in this rest frame are transverse to the direction of mean motion and in fact if you actually measure the structural property of this what we call flocking liquid it turns out there are actually is a smectic type state there are rows of cells which are kind of squashed in the direction of mean motion and fluctuating a little bit in the transverse direction and the per correlation function shows more strong correlation along the direction of motion which is the red then in the direction perpendicular to motion which is the blue so more quantitatively so we have bought now a solid liquid transition and we have also a flocking transition how do we quantify those well for the solid liquid transition we use again the mean square displacement and this effective diffusivity that I introduced before for the flocking state we sort of use conventional order parameter which is essentially the mean direction of motion and then you can also calculate the fluctuations in the mean direction of motion sort of the susceptibility which will have a peak at the location of the transition so here is the flocking transition between non flocking and flocking solid these are the this is the order parameter that goes towards 1 for increasing number of cells increasing system size and here is the susceptibility that gets more and more picked as you increase the system size and here the same thing for the liquid state with a very similar behavior so the sharpening of the peak of the susceptibility with system size suggests that these may be a continuous phase transition unlike in particle models with nearest neighbor interactions and in fact if you plot the location of the maximum of the susceptibility as a function of system size you see scaling and in other words this system is much more similar to particle let's call them particle models with so-called topological interactions which is not surprising because the energy itself and the forces that drive the dynamics are indeed topological in nature in this system and I think for the people in the audience that work on Vichyakti models and would be interesting to kind of look a little bit more closely at analogies between and correspondences between this model and possibly the triangulation network that you can generate in the particle models with topological interactions so here is now the phase diagram a little bit more quantitatively again alignment interaction and shape index P0 so we have a static solid and a static liquid for low alignment we have a flocking solid which is a state that has a finamine velocity and zero diffusivity and the flocking liquid which is a state with finamine velocity and finite diffusivity the red and green points are obtained numerically the blue line is actually an analytical estimate which is essentially obtained by making a model of a cell as a caged flocking particle calculating the mean square displacement and equating the effective temperature you can get to that to the typical energy barrier that will be required to escape from the cage and as you can see it works actually quite well with only one adjustable parameter here which was actually the same as was determined for the transition for zero alignment and the black points if this works ok the black points are sort of a semi analytical estimate again that is estimated for the transition between flocking and non flocking liquid essentially for the liquid to become flock that is to move in a correlated way it has to be that the rate of alignment is faster than the rate of structural rearrangements you always have structural rearrangements in the liquid but when the rate of alignment is faster than those then you can get this flocking liquid and you can actually compare perhaps not quite quantitatively but there is actually a nice comparison with experiments that can be done by calculating a four point density correlation function which is familiar in glassy physics in the sky four which essentially look at this curve in red this is in the liquid it will have a peak the location of the peak of this four point correlation function sort of describes so what you have in this dense liquid near the transition you have the sort of packs of cells are moving together and the location of the peak in the sky four essentially describes the lifetime of the peak describes the size of this coherently moving pack of cells and as you can see in our model the green is without alignment that would be the non flocking system and then you get this great announcement here when you have alignment you have these correlated motions that are seen in the experiments but actually experimentalists have also calculated chi four from their data and you see a similar behavior with the peak and notice that as time goes on in the liquid the peak moves to shorter time meaning the system is becoming more and more liquid and notice also that there is a big difference so just like in our simulation between the size even though these data look the same the scale here is 10 and this here is 150 so the peak in the flocking liquid where you have these correlated rearrangements is much larger than that where rearrangements are very localized so let's see if I have a few more minutes I think I do so I told you I started out showing this one dealing assay and saying that one of our goal was to understand our cell correlated behavior to move together and clearly this alignment interaction is one possible mechanism but so far we really only looked at it in a system with periodic boundary conditions and actually no boundary moving coherently and there is actually another type of calculations and modeling you can do for this system to answer the question so we gonna go back to wound healing where the key question that has been actually around for some time is how do cell transmitting information to correlate their motion and move coherently and fill in the wound so let me see if I can get these to go again so this is the front of cells epithelial cell in a wound healing assay from the level of Javier Trepine, Barcelona and what is shown here in color are the forces that the cell exerts on the substrate as they are moving along and that red is forces to the left right Lewis forces to the right but the main message from this picture is that all cells are exerting forces of about equal magnitude on the substrate and a long standing question in this field has been whether, so what drives the motion and for a long time people thought that the motion is driven by so called the leader cells that essentially pull the one behind but clearly this is not so here because essentially all the cells are participating in this force generation that gets transmitted throughout the entire layer and by the way time scale for this kind of dynamics again is ours cell move really slowly this kind of epithelial cells so the key experimental finding that is associated with this idea that all the cell are participating in the dynamics is that and again we have here again an expanding cell layer and again what's in color is again the force that the cells are exerting actually you could think of this color as a measure of the local pressure in the system and the experimental finding is that in an expanding cell layer like this information is actually transmitted via propagating mechanical waves that is if you sit right say at the middle of your expanding monolayer and the measure for instance the variations in cell area which correspond to variation in local strain of the system so they describe local deformations you actually get this periodic behavior you get traveling like waves or ripples in cell density much like sound waves in air of course these are very slow traveling waves they travel millimeters per day but they are traveling waves you can see them by measuring cell area by measuring local strain or actually by measuring stresses which can be inferred from a measurement of the forces of the cell exert on the substrate and it turns out you can actually capture this behavior even more simply than with the kind of mesoscopic model of Voronoi models that I just show you with a very simple model by describing your cell layer as an active elastic continuum and what do I mean an elastic cell sheet with elasticity cost for elastic deformation but the activity comes from forces that are internally generated through the coupling through these motor proteins that transform chemical energy into mechanical work and if you incorporate the dynamics of these and the dynamical turnover of these motor proteins that gets bound and unbound from the network that constitutes the cell cytoskeleton these you get a dynamical feedback between forces and protein activation that actually results in traveling waves and in fact here are the traveling waves in again the strain rate in red the stress in solid blue and the strain in dash blue obtained from this simple continuum model which I thought I would mention because I thought I would have interest in people here and here are so called chemographs that these are plots in color of the local deformation for the monolayer time is down distance is in the middle so you start with a monolayer which is only this big and it expands and the blue and red denote positive and negative deformation and these characteristic cross structure indicates that these are in the traveling waves as seen in the experiments these are actually deformation rates both of them of the deformation measured in experiments so and actually one of the things we are doing now is to go back and look in more detail at this one dealing assay using this mesoscopy of anoint model to more precisely try to understand the interplay between sort of pulling forces at the boundaries and these turn over chemical forces induced by the motor protein so I think I should probably try to conclude so what we've been trying to do are essentially our big goal here is to construct a phase diagram for tissue and actually this is not a cartoon this is quantitative and the phase diagram for the model I showed you contains is the axis what I showed you before is just the slice in the motility cell-cell adhesion plane the cell-cell adhesion is controlled by this parameter p0 the target cell shape but we've also looked at the effect of the persistence of the dynamics that can actually fluidify the system because it enhances sort of correlated rearrangements that tend to make the system more fluid meaning cells can escape from their local cages if their dynamics is highly persistent as it often is for cells and the idea is to construct effective theories of tissues where many molecular scales or genetic parameters may be fed into a single effective parameters such as the persistence the motility of this target cell shape and these parameters perhaps can be accessible through experiments of course many things we are exploring many things that are still missing here such as the role of cell division and death the role of heterogeneities differences in cell properties the role of the coupling to the environment which is actually very important in tissue I also showed you that if you actually add to this model alignment of cell polarization with the local forces or the resulting velocity on the cell you actually get this large-scale streaming you can get these flocking, solid and liquid states and although I don't know that there is some suggestion that the unjamming driven by this particular protein RAB5A does indeed correspond to the fluid state obtained there has very strong similarities with what we call here a flocking liquid state that was the state where you saw these large-scale collective rearrangements now one interesting thing here is that we find that the flocking transition about in the solid and the liquid is continuous which is consistent with what is seen in particle models and suggests that indeed this fact the transition being continuous might be generic for all these sort of topological type models and we find these sort of structural asthmatic order and dynamic aligners entropy as well which would be interesting to look for in experiments and I did not talk about this but I wanted to mention again that we have actually developed also a continuum model of shaped driven flocking and rigid transition sort of combining these two at a continuum level and what is interesting about this model is that it provides cells have to undergo, they move in order to create specific patterns especially morphogenesis and this is generally understood by coupling to fairly complex reaction diffusion processes and the diffusion of various chemical called indeed morphogens that have been very elusive people have not really seen in the experiments and so what our work is going in the direction of suggesting sort of a mechanism purely mechanical mechanism of rigidity sensing associated with the fluid like or solid like nature of the system that could be actually complementary to chemical sensing and I can tell you more about that in another time so let me just finish by showing again the pictures of the people who did the work and thanking various agencies that provide money for those of you, thank you for listening


A assuming it gives us some experience of knowing what the atmosphere awtt ychygwch gyda what it's like to play at the Den in a competitive fixture. Yeah, it's going to be obviously a daunting fixture, nothing' we should fear because like yourself we've gone on a good run now and, just like them, they'll be fancying themselves after their little run so it'll be a good marker on to see whereabouts we are in the promotion chase because their side that probably shall be up in the foot there. dda'n ffo wleisio bywb dda'n ddim.


Good afternoon everyone, I am Dario Presuti, policy analyst from the Free Software Foundation Europe. We are a charity that empowers users to control technology with the use of free software, also known as open source. First of all, of course, let me thank everyone involved for organizing this important consultation and also the rapporteur, Mr. Graham Falk. We in general support the proposal of the Commission on the use of the Solidarity Act, published in April 2023. And more in general also the efforts that the commission is making in order to strengthen the cross-border capacity in the U to detect, prepare and respond to cyber security threats and attacks. We also welcome the efforts of the Committee of the Region and the ACRON Commission in handling the text of these regulations. More in general, if we consider the scope of this regulation and also the commission strategy, it is clear that cyber security is also a matter of cross-border collaboration with different stakeholders, which we believe can only be achieved by prioritizing free software and including its community, and I will explain shortly why. So digital services often and used by our public administrations are the critical infrastructure of the 21st century. And in order to establish trustworthy and resilient systems, public bodies must ensure that they have full control of the software and the computer system at the core of their state digital infrastructure. And this power is only possible prioritizing the use of free software. So we need software that guarantees freedom of choice, access and competition, and we also need software that helps public administrations regain full control of their critical digital infrastructure, allowing them to become and remain independent and sovereign. And in order to do so, we free software, which gives the possibility to use, study, share and improve the source code of software, enhance these resilience and sovereignty in this matter, enhancing also cross-border cooperation. So in terms of cybersecurity, free software, thanks to these four freedoms, allows also independent external and internal audits and give prestige to the software, where security bugs and backdoors can be found easier and fixed almost immediately and independently. And also free software through collaboration as the potential to be more secure by definition. In the proposed legislation, a cybersecurity community is indeed mentioned and that shows the willingness of the commission to involve several stakeholders, but the definition of these communities is missing. The commission in the past already established fruitful collaboration in the field of cybersecurity, also with the free software community. For example, the FOSSA project and also through the open source observatory and the current join up platform. But in order to benefit from this community and guarantee this cooperation in the long term, the cybersecurity community needs to be defined in this proposal. Indeed, relevant stakeholders are not currently defined and it is not clear who those stakeholders are and in which terms they should be taken into consideration. We propose therefore the definition of cybersecurity community, meaning a community composed of representative from member states, the commission, all the relevant institutions, academia, the private sector and the civil society, meaning the free software community as well. The community would strengthen the relationship of the commission with all relevant stakeholders, including civil society and the free software community, which has already proved to be happy to help in developing digital public goods. For example, during the COVID-19 pandemic and the development of the COVID-19 tracking apps. Free software allows cross-border collaboration and the community around those software will be able to collaborate in a union-wide approach, also at a local level. And free software gives autonomy to its user, helping to develop and maintain tailored software that suits the administration needs, not just the vendor business model. And far and more, a free software license allows a limitless number of installations to be run without paying extra money and providing the freedom to use the code for other projects, encouraging innovation, together we're ensuring solidarity among new institutions. And this is only possible with free software. Finally, a strong accent on this regulation is also put on interoperability in order to better respond to these cyber attacks. In these regards, we think it is essential to take into consideration also the Interoperable Bureau Act, which is a critical initiative that fosters and gives a legal framework to cross-border interoperability across the union. This act recognizes the pivotal role of free software in achieving seamless integration and harmonization of digital systems and services. And this is even more necessary when we talk about cybersecurity. Once again, by prioritizing free software, we can enhance cross-border cybersecurity. And so to summarize, once again, we strongly believe that only by prioritizing free software and by defining around that a cybersecurity community, European-wide, we can have secure but also sovereign and interoperable digital infrastructures. So that was my last point. Thank you. Thank you for those points. As you said, cross-border collaboration on software is something that we will mention in the report. And of course, we need to define the stakeholders around this also so that we can collaborate and strengthen with work when it both comes to software but also sharing information points and what kind of software that has been breached and what kind of software that you are able to use. So to strengthen your own systems.


Welcome to Math Analysis for Hedgehogs. Did you know that you cannot trust any compiled timestamps in Windows system files? Well, here's why. So I would like to show you something. Just open a file in your System32 folder. You go to Windows, System32, scroll down a bit, you have a ton of DLLs in there. And open this file in Potex Analyzer. And now check the compiler date. In a lot of cases, the compiler date will not make sense. Okay, 2008, maybe that makes sense. Let's just pick some other file. Here we have one. That's 1981. That can't be right. And if you open files here, you will have like random compiler dates. Like they are all over the place. They can be in the future. They can be too far in the past to make sense. And like it's the case here. And why is this? Why are the timestamps like that? Now the answer is in the debug portion of the file. You see here there is a debug entry called repro. And whenever this entry exists, you cannot trust any of the time date stamps. Go to this entry. You see here repro hash. And you see here as a description for this debug entry type, it stands for PE determinism or reproducibility. What does this mean? That means this file has been compiled with a specific linker flag called be repro. And that linker flag causes the file to override all timestamps with a part of this repro hash. And that part of the repro hash are the last two bytes. Because if you check this, the time date stamp here, that's again this with 1981. So that's the exact same one you saw in the PE headers. And here is the actual value. And that is 16, 7F to E, F5. 16, 7F to E, F5. You see that? So this is actually the last part of the repro hash that is used for the timestamp. And not only for this timestamp, for the compiler date, but for all of the timestamps, or almost all of the timestamps you find throughout the file. So it's also used for the timestamps in the debug entries. So all of these debug entries, they have timestamps as well. And that's what is used here. The purpose of this linker flag for reproducibility is that if you do not change the code, the resulting executable is guaranteed to have the very same contents. And if you use timestamps, those contents will change because the timestamps are dependent on the compile date. So in order to make this work and produce the very same file contents for every compilation, if the code didn't change, you need to replace the timestamps. And they just replace the timestamps with part of the repro hash. So that explains it. And now you know, whenever this debug part or this debug entry is present, do not trust any timestamp.


Everybody it's Eric Johnson. What is one of the biggest challenges young throes have trying to get into the throw generating speed? If you don't get this entry access right, it's gonna be problems. Here's a couple of drills to help you out. Check it out Everybody is Eric Johnson. We just wanted to say real quick We hope you're safe healthy keep up your training.  Keep training you guys stay safe. Take care Everybody it's Eric Johnson for Maritime Throes Nation and in today's video We are here at home and home training is gonna be one of the things that we're required to do and right now It's definitely pretty tough when we understand that we have a lot of issues with training facilities Getting to our weight rooms getting to our throwing areas seasons and canceled You know being canceled and different things like that. So what we want to do though It's it's very easy and it's understandable to be really bummed out. I know as a coach It's really disappointing for me. However, there are whispers of Competitions gonna be held and we are trying to work on stuff as well so that way when we get the green light We can organize some meats to give some of those athletes that didn't have an opportunity to come compete now That being said one of the super important things that you want to make sure that you're doing is not giving up You want to keep bettering yourself learning more and that's why we're trying to put out more content for you guys More often so that we can kind of keep that mojo moving so you guys can feel better And then hopefully come out of this and have some opportunities to hit some meats now that being said one of the things We're gonna cover today is one of the big challenges that throwers have and that is basically getting to this part of the throw That little simple rotation tends to be a pretty challenging thing for a lot of young throwers So what we're gonna do is we're gonna go through two drills We're gonna do we calls a 90 degree walk around and you're gonna notice the position of the entry leg And so I get here so I go I go 90 degrees 90 degrees 90 degrees and then 90 and of course I'm back to where I started now One of the things you're gonna notice is the position of my entry foot That's really really critical and the entry foot has to be pre-turned right sometimes throwers are turning They're doing this. This is one of your common mistakes that kills a thrower We're seeing this and turn and that is gonna be so much harder to do So one of the things we're gonna do with this drill is when we're taller and we use something like our drill band So that we can coordinate the upper body You're gonna see that I'm gonna move this and I'm gonna get my 90 and you're gonna notice how this is always ahead, right and so This is basically what we refer to as a 90 degree walk around super simple You're gonna notice the key is what we're gonna teach you is to stay on the inside of the foot Don't go to the outside Because one of the things we always talk about at our events is that if you stay on the inside Notice the turning of the axis if you stay neutral look at the turning of the axis and if I stay Outside of the foot look at the turning of the axis So watch me try to do the 90 degree drill on the outside of my foot Okay, can I do it? Yeah, I can but look at the difference of how that looks from this See how I'm much more. I have much more load and I'm much more dynamic So one of the simple things you want to do is try to practice that stand the inside of the foot and keep your Sweep leg wide and your knees apart and another thing that we'll do with our bands. Let's pop them up All right, okay, so you're gonna notice that when I put the band on I always have it on the lower body a little loose And you're gonna notice when I turn I'm creating a little bit of tension One of the mistakes is athletes tend to stand You want your knees open on top and I can still be tall and now when I turn that foot and I feel that 90 degree step I'm gonna see this so I purposely have the band loose. I have the upper body. I have shoulder hip arm shoulder separation We're gonna turn we're gonna get that 90 degree step 90 degree step This is a really simple way to start understanding your throw one of the things We're gonna teach our throwers is to go 90 degrees and then what we're gonna do is be able to step Step through the throw and you're gonna see the band comes off because when I transition from here to here My legs do come closer together, and they're not staying way apart. Okay, this is why We are recommending you guys start out with the 90 degree walk around because there's a lot of mechanical points that you want To get right and again inside our system. We talk a lot about that if you don't know we have a system check


Alrighty, I'm gonna go over in today's video about all the amazing opportunities that you as a family or a person have to save a ton of money in the 2022 season at Canada's Wonderland. Wonderland has an amazing promo and deal going on that isn't necessarily being talked about and I know a lot of the enthusiasts know about it but I know I have a lot of general public that watch my videos that don't know too much about Wonderland and I'm here to help you so for any of you that have a 2021 season pass or you got a season pass in 2020 your season pass if you do not know is actually good until Labor Day 2022 including its drink plans fast lane meal plans anything you have on there including parking it's good until 2022 Labor Day now the reason it ends Labor Day a lot of you may be asking is Wonderland always runs these amazing promos around Labor Day when they announced their new attractions if you haven't noticed Wonderland will announce a new attraction or experience and they put season passes on sale and if you buy a season pass around the Labor Day you actually are able to get into the park for the remainder of the season so if you buy your 2023 season pass at the end of 2022 around Labor Day you'll be able to get in for the remainder of 2022. Wonderland does a lot of promos that they don't get a lot of recognition for in fact it has upset me a bit the amount of negative attention that people have been giving Wonderland for how they're opening this season and a lot of these people don't realize that if you buy a season pass right now and any add-ons it's good until Labor Day next year not many businesses are honoring stuff like that and the company that owns Canada's Wonderland has done a tremendous job in providing their guests at their parks that were shut down during COVID with all these added bonuses. I really don't see how anyone could be disappointed in the season pass honors program or whatever you want to call it the gift that they've given you for something that's been out of their control and completely not their fault so again one your season pass is good until the Labor Day 2022 if you have a meal plan drink plan fast lane all season fast lane which is $450 right now $50 on sale or all season parking it's good until Labor Day 2022 so my suggestion to you is to go to guest services or add it onto your pass any of those if you don't have them if you don't have the meal plan now's the time to get it you're gonna get so much use out of it and with Wonderland potentially most most probably for sure upping their capacity this Friday coming you're gonna get really good use out of anything that you add on the park is almost going to be back to normal almost starting this Friday and then hopefully sometime around August 6th it'll be back to normal and those season pass benefits that you're adding on right now will be amazing so I'm hoping I can help any families that are watching this channel right now truly get those benefits out there unfortunately the payment plan program that Cedar Fair that owns Canada's Wonderland normally runs at their parks is currently down at all their parks we don't know when it's gonna return I'll try and get an answer from Canada's Wonderland but they may not know themselves sometimes this is like an executive decision and it probably will return around Labor Day 2022 or even at the beginning of 2022 so that would be my guess for the payment plan for anyone asking about that but that is coming as an assumption again I would try and contact Wonderland to get the proper answer I will see if I can reach out to someone from Wonderland and get an answer on that as well just because someone reached out and asked you know I have a family of nine and normally we put our season passes on a payment plan but this year we can and it's almost virtually impossible to get the season passes that we normally do with the drink plans and meal plans and be able to pay them and that's a very valid question and a lot of families in Canada and around the world right now are probably asking the same thing and questions about visiting or even just regionally traveling because a lot of people are gonna have to travel regionally versus across a country because a lot of people may not have the money they normally have due to COVID but nonetheless if you have any questions about any season pass promos any discounts any questions or advice you want please comment down below I will do my best to help you again I just want to help I don't know I had to pause to think about that I was I guess looking at anyone that has followed my channel for a while knows that I rant and ramble sometimes too much but yeah anyways that's an amazing deal I wanted to let anyone on the Washington channel know that because we were getting a lot of DMs being like oh like I didn't know that it was good until 2022 so I just wanted to get the message out there because I know enthusiasts know but I want to make sure anyone watching my channel knows that because that's an amazing deal and if you don't have the meal plan or drink plan get it it's a really good deal impossible to pass up even the fast lane is such a good deal for those that don't like waiting in line for $50 for a year and a half a fast lane it's good you're in Halloween hunt as well that we're hearing so yeah definitely if you're gonna do it though double check when you do do it that it is good until the Labor Day 2022 but we've been told by very a lot of people at the park that it is so again take advantage of it thanks so much for watching guys hopefully you had an amazing Monday and that your Tuesdays going well and yeah thanks for watching and have a good one guys bye