It is Brett and this 2022 Ford F-250 Crew Cab Long Box XLT is stock number 12633Z. We are here at Summit Automotive in Fond du Lac, Wisconsin, your new and used heavy duty truck headquarters. This 2022 Ford F-250 has the 7.3 liter V8 gas engine, puts out 430 horsepower. All of our vehicles go through a 130 point state of Wisconsin inspection process. They get a fresh oil and filter change, all the fluids get checked and tapped off before being made available to our customers. We're going to go inside underneath, start it up, take a look under the hood in this video. Carbonized gray metallic is the color. We shoot all of our videos in 1080p, 60 frames per second, so if you have HD capabilities on your computer, tablet, smartphone, or television, I highly recommend turning them on right now because it is your best way to check out the quality, condition, and options of the truck before seeing it in person. If you like the video and how we do things here at Summit Auto in the upper right hand part of the screen is a subscribe button to our YouTube channel. Click that and then click the bell notifications. You'll get updates on the videos we do each and every day here at Summit Automotive. Click the like button too on the video if you like it. It comes with the 18-inch painted alloy rims and it has Continental Conta-Track LT 275-65 R18 tires. These tires are like new, still have the little wear knobs on them, and that's because this truck only has 291 miles on it. You'll see in the video that this thing is basically brand new. What used? A driver's side front fender, no dents or dings on there, it has the crystal clear headlights, factory fog lights, and front bumper is in excellent condition. I didn't see any major dents, dings, or scuffs on there. Get the chrome-trimmed grille on this one and the hood is absolutely perfect. Passenger side front fender is in nice shape as well and the passenger side rim, front rim, no scuffs or scrapes. Carbonized gray metallic's got a lot of metal flake in it. It's a little bit lighter than the old magnetic gray that Ford had for their superduties. I kind of like it. As you go down this side of the truck, take note of how clean the body is, how reflective and mirror-like that paint is. We take these HD videos so if you are far away or even if you're close by and just cannot make the trip down but you're still interested in purchasing the vehicle, you can see the truck here, the truck and have confidence in the vehicle that you're looking at before you even get here. So when you do get here there's absolutely no surprises and you can make a smart and informed buying decision before you get here. And if this video helps you make that decision, let your salesman know that you saw the video. It was helpful and that Brett sent you no scuffs or scrapes in the back rim. Back tires are like new as well and that frame and underbody is an exceptionally nice condition. It does have the camper package with the anti-sway bars and of course it's going to have all the remaining factory exhaust. And the underbody is basically new. Cab corners, lower rockers, has the nice big step bars that go to the bed, coming around to the back, rear bumpers in great shape, back up parking sensors, full towing package which includes a receiver hitch, four pin and seven pin wiring. The tailgate is absolutely perfect. It does have the tailgate step assist which is a cool system. You also get the LED bed lighting. And you can see that the bed looks like it's never been used. Very nice and clean back here. Tailgates really light, closes nicely. And as you go down the driver's side, just as clean as that passenger's side, box looks really good and for full disclosure, no scuffs or scrapes on this back rim. Down the rest of the side of the truck looks really good. This one does have the door code entry. We do have the code for this truck and if you ever wanted to figure out what your 17 to 22 super duty door code is in the upper right hand part of screen, got a video to show you how to do that, how to find it on your own. Has blind spot monitoring, the power scope mirrors, they power fold in, power telescope out, they have directional signals on them as well. Inside the XLT package gives you the gray cloth interior. Power driver seat, no rips or tears on the seats. This truck is like new inside as well. Power driver seat, lumbar, factory, all weather floor mats, auto headlamps, power pedals, LED side lights on the mirrors, tilt, telescopic steering wheel, power windows, power locks, power mirrors. Now these mirrors do power fold in, I always like showing both sides so that you know that both sides are working properly. And of course this truck is going to have the full factory bumper to bumper and powertrain warranty on it as well. We'll hop inside, check out the miles, radio and everything that this truck has to offer on the interior. So you can see that this one only has 291 miles on it. You do get a compass, digital speedometer on there as well, instrument cluster is very nice and clean. Cruise controls and information center controls on the left, Bluetooth and audio controls on the right. This one has the 10 speed automatic transmission with the optional tap shift. You get the sync 8 inch radio, AM, FM and Sirius XM radio capabilities as well as Bluetooth. And then you have all your different apps including your mobile apps, Ford Pass Connect and then you can do Android Auto, Apple CarPlay on here as well. This is also where your backup camera shows up. Truck's got to be on for that to work.  This truck's never been smoked in and once again is like new with only 291 miles. You do get six upfitter switches, map lights and we'll take a quick look at the back seats and then we'll start it up. Take a look under the hood. Back seats are just as clean as front seats. No rips or tears back here and it does have the latch child safety system, fixed glass rear window with the built-in rear defrost, storage compartment back here, all weather floor map back here. This collapses down flat and yeah, very, very clean. Child safety locks on the back doors and that's that. We'll start it up, take a look under the hood. Starts right up. No check engine lights or anything like that. There's your backup camera that works nicely and you can zoom in on that receiver hitch so you can get hooked up to your boat camper or trailer the first time every time. I would personally like to thank you for checking out the video today and hopefully from this HD video you will have been able to verify the quality and condition of this truck all the way around inside and out under the hood. We have the 7.3 liter V8 gas engine, 430 horsepower. Engine bay is very clean, runs very smooth. There is your emission sticker. Once again all of our vehicles go through 130 point Wisconsin state inspection, get fresh oil and filter change, all the fluids get checked and topped off before being made available to our customers. I would highly recommend this truck from a quality and condition standpoint. Obviously 291 miles, not much can be wrong with it. This is the one. To see more pictures of this truck or one of our other 450 new and used cars, trucks, SUVs, minivans, wranglers, halftones, 3 quarter tons, one tons, you name it. We've got to go to that website right there, www.SummitAuto.com. All pictures and descriptions of every single vehicle from two locations all at www.SummitAuto.com. If you'd like to check out more HD videos you can go to www.youtube.com. Remember to like, subscribe, and share on this video and all the videos that you see there. Click the bell notifications and you'll get updates on the videos we do each and every day here at Summit Auto, in fact in a second. You will see a link to subscribe to our YouTube channel in the upper left, the link to more F-250 videos like this one in the upper right, a link to this vehicle on our website in the lower left and a link to one of our latest YouTube videos in the lower right. Click those, check us out and we're super excited to help you with this like new 2,022 Ford F-250 Crew Cab Long Box XLT in carbonized gray metallic base gun for checking out the video. Remember to like, subscribe, and share.


We are live Hello, everyone. Welcome to this 110 Latin American webinar for physics It's a pleasure to have today Dan Carney who will talk to us about Testing quantum gravity in the lab. Dr. Daniel Carney He studied his PhD at the University of Texas at Austin and then after that he worked as a postdoc at the University of British Columbia and then at Fermilab and the University of Maryland together in a joint position and today He has actually the title that many of us always want. He's a scientist at Berkeley lab and He will tell us how to measure quantum gravity today. Welcome Dan Yeah, thanks Walter and everybody for the invitation to give the talk I'm very flattered and honored to do this. It's eight in the morning. So I'll be drinking coffee A little bit at the beginning. I hope you don't mind So I should share my screen again. Yes, please. All right so Yeah, so So as Walter said, I'll talk about testing quantum gravity in the lab and I think the title often, you know gets people very Emotionally excited because it sounds crazy. So the first thing I want to do is go through and just say what exactly I mean It's sort of a very high level So my my origin in physics is actually the same place as Walter We did our PhD so they got there in Texas in a string theory group And so I'm really a high-energy physicist in my soul so If you want to think about quantum gravity, you can think about it in terms of the energy density you're interested in so string theory or loop quantum gravity or Asymptotic safe gravity or there's other possibilities, you know, these are models of the quantum behavior of gravity at Extremely high energy densities. So so here I actually gave a number just to point out how how insane these densities are So this is 10 to the 123 electron volt per centimeter cubed That's that's the scale at which things happen that are like black holes randomly start forming because there's too much matter around and You know, we have a breakdown of all the equations other than the ones of say string theory You know, and this is a very nasty problem These are very hard things and it's one of the deepest questions in physics What is the correct model of gravity at these high energies? and So people have been working on that for I don't know 100 years if you want to think about it that way Certainly intensely working for 50 years In this talk, I want to focus on a very Low energy question so much much lower than these kinds of energy scales and this is a question sort of underlies All these high level question the high energy questions in some way So at low energies, you could even ask this question. Is gravity quantum in the first place? And so sorry minimum there we go So is gravity quantum at all so so all these high energy models like string theory They all assume kind of from the beginning the fact that The gravitational field itself should be treated Quantum mechanically, but what's the reason we think that that's The case I mean, we don't actually have some piece of direct experimental evidence for that It's sort of the simplest model if you have certain, you know prior ideas like quantum field theory describes everything But you'd like to be a little more, you know, experimentally hard-nosed and say, okay Why, you know, can I do an experiment that would tell me for sure that gravity is itself quantum mechanical? If the answer is yes, then it means that all of these questions that high energies are, you know Continue to be worth asking you might though be surprised You never know gravity is a strange force and people have certainly thought that maybe Even at low energies quantum gravity could be, you know, something quite different than what you might think in terms of say gravitons Proturbative general relativity So I list some some options people have talked about there are options where gravity emerges from some kind of thermodynamic limit of some microscopic thing We don't know There are even crazier ideas like Roger Penrose has suggested that Gravity will cause wave functions to collapse in quantum mechanical systems even at low energy And so so broadly speaking what I want to talk about is testing some ideas like this at energies that we can actually achieve In the lab and this is a really just a tabletop lab energy This is not the LHC which would be in another 10 or 20 orders of magnitude higher But still way below this far off violet string scale So this slide is like my personal history into this question. So is gravity quantum? So this is the question I'm really gonna focus on and I started thinking this way at the end of my my graduate school career because Freeman Dyson here wrote this great paper and the title is is a graviton detectable and this is such a nice question This so can I even know that the graviton exists in a very direct sense? Just find one. Okay, and in Dyson's answer to this question is no, you cannot detect a graviton So you have to be careful about what exactly it says what exactly he says is He asked the question. Can I build a gravitational wave detector? You know like LIGO, but scale it and make it so sensitive that it would actually click when a single graviton of the appropriate energy goes through it and Dyson answer to this question is no the argument is that if you take sort of a LIGO type detector And you sort of rescale how big is it how much laser power and so forth It's always gonna have so much power so much energy density in a certain radius that that device itself will collapse to a black hole Or it'll have to be the size of the universe or some, you know horrible scale But just me it's not a this is not an answer about in practice. This is really an in principle. The answer looks like no That said it does rely on the LIGO type detector for a gravitational wave, but okay So I actually got quite depressed when I read this paper I thought this means that I'll never know if gravity is quantum mechanical and I can't test it But a couple of years later, you know I sort of started reading a little bit more about quantum information theory and This is a picture of John John Stewart Bell here who really, you know, I think made a lot of this stuff concrete And I realized you can ask a different question than can I detect a graviton you can ask can the gravitational interaction do something uniquely quantum This is what a bell test asks about bells bells test bells inequalities But they ask is can I have say two spin half particles and in some state and some property of that state can only be described Quantum it cannot be two coins, you know, classically sitting around getting flipped. It has to be something uniquely Weirdly quantum mechanical. So we'd like to ask the question. Can you do something like that with gravity? And the claim in this talk is going to be that yes You can ask this. Yes, you can do it such an experiment and I'll and then you know, yes, it will tell you something interesting about these sort of more high-energy questions about gravitons, for example So with that sort of intro the rest of the talk is set up as follows So I'll talk just by starting about some experimental scales. So this will look very different I'm going to show some pictures of actual things in labs I just want to show you kind of what scales to think about and how this stuff could be possible at all Then I'll move into a quick discussion of the basic theoretical ideas sort of riffing on the introduction Then I'll talk about two Experimental implementations that have been proposed. So one that was a few years ago now and one that we recently put Up on the archive And then finally I'll go back and I'll sort of put a connect what I've shown you to be sort of more fundamental questions If you want about graviton strings and so forth So I want to emphasize since I believe the audience does not say all gravitational physicists and such that the the really The amazing thing that's happening in the world right now that that is driving Me to even think about this kind of thing is is this emergence of what we call macroscopic quantum coherence in laboratories So this picture on top is the Google sycamore quantum computer chip The thing on the bottom is the mirror at LIGO. Okay, this thing has I don't know 50 qubits on it It's very small. Although it's you know, maybe centimeter on the table The mirror LIGO is 40 kilograms and what's quite remarkable is that both of these objects behave quantum mechanically And you can really you really have to worry about their quantum mechanical properties when you use them So that's obvious probably in the quantum computer in LIGO This the statement is that you measure Motions of the mirror at a size actually about a hundredth the scale of the vacuum fluctuations of the mirror So you really talking about quantum behavior in a very large systems And that's the kind of thing we're gonna need to be able to do a test of gravity because obviously gravity only works at sort of large masses So to give a sense of how large and what kind of scales we're gonna be thinking of this is a simple sort of figure of merit cartoon So, so let me show this is two masses. Let's take them to be the same I I separate them at some distance and what I'm drawing on the left with these two balls is you know Consider the mass this left mass being either in this one position or this other position separated by some small distance and I can ask so if I if I just took this thing put it in the Schrodinger equation and ran time evolution I can ask what's the the phase of the wave function picked up between these two masses? More importantly what I can ask is what's the difference in the phase between them this mass being on the one position or the mass being on the other position This is an easy calculation. You just plug the Newton potential into e to the IHT and calculate it And what you'll find is that the phase difference, you know, it has a simple-looking formula It's got a G Newton. It's got the mass squared. It's got D squared So, you know, there's the Newton fourth and then there's some factors of positions and times to make the thing into a phase The phase is sort of order one with Reasonably sized objects. So I put in nanogram masses. I put in micron distances and I put a second for the time that you run this So you can obviously move these numbers a little bit But the basic statement here should be at these sort of, you know, tiny but macroscopic scales nanogram second stuff like that That's when these types of low-energy quantum gravity effects, if you want, will become appreciable This is the scale at which I can actually measure the relative Newton potential between these two masses There's a nice conversion factor. Not everybody knows. I like to emphasize it that there's a M squared here and it's in units of G Newton So in high-energy physics, we would call that the Planck mass and the Planck mass is about the order of a hundredth of a milligram So people often think the Planck mass is some very super high-energy scale But in a way of looking at it, it's actually a very terrestrial scale This is like the mass of a typical salt grain and that sort of underlies why this could be, you know, doable So some experimental systems where this would be relevant Okay, so I just show some pictures to show that there's many options But typically what these are are mechanical systems So this is a mirror hanging on a string that can swing just like a mirror and LIGO This is a drum head that can vibrate. It's on a chip. This is a picture of a little dielectric bead that's levitated by an optical field And all these devices and a number of other devices are basically designed to operate as very sensitive force detection sensors So this one I showed the numbers just again emphasize these scales So this is an actual device and what it's designed to do is measure milligram scale objects through gravity at sort of millimeter distances And numerically just to give a sense that the Newtonian force at those scales is about 10 to the negative 17 Newtons And these kinds of devices pretty routinely now achieve sensitivities to forces at the level of 10 to the negative 21 Newtons Per root Hertz means it takes one second to resolve that So you guys should resolve a force much smaller than that now in these high level optimal mechanical systems Okay, so now back to the theory So I want to explain exactly what we want to test So this is probably the hardest part of the talk if you haven't really thought this way before it's a bit novel Okay, so so what do we want to test so I keep my picture of Bell here to emphasize who you know how we're thinking we're thinking like a hardcore quantum person So we asked the question is gravity quantum so a more concrete set of questions of the can the gravitational field be put into quantum superposition to make Is there a wave function for the gravitational field can I do all the usual things put it in superposition and so forth This is actually the same question under standard assumptions about quantum mechanics but you can think of them as different more generally Can the gravitational field be used to entangle to quantum systems. So I like to think of the second one and that's a sort of very concretely testable question and that's sort of what we'll focus on So what this would mean sort of pictorially is shown here. So what I imagine is I have some source mass this big ball and schematically I'm going to draw these, these wells so this means the metric field the gravitational field source by this massive object. So this is space time bending here a little bit because this masses around. And I prepare this thing and some definite location and I prepare a probe and definite location. And now the kind of experiment you want to do is, you take this mass and you prepared into a Schrodinger's half state where it's not in one definite position but in the superposition of say left and right. And so, under normal assumptions about how gravity would work you would think that then the metric the gravitational field itself would also be superpose. So in this state if you're familiar with quantum, you know, ket notation, where the masses on the left and the metric, the gravitational field is is on the left, plus the masses on the right and the gravitational field is on the right. So in some sense we're testing whether this is true, does this actually happen.  Okay. Then I have to ask the question, how does this little test mass respond to the superpose gravitational field. And that's what's in this third cartoon. So if gravity behaves quantum mechanically. And I'll be a little more concrete later. What you would expect is actually that this test mess will become entangled, you know, with the with the source mass. On the left, the test mass will go to the left, if the source mass is on the right, the test mass will go to the right. And so the total evolution of the wave function of the universe in this little picture is that the, you know, the two masses branch, there's a branch where everything's on the left and branch everything's on the right. And this is a canonical entangled state in quantum mechanics. So what we're asking is the right description, that's one way of thinking about it. So why would I care about this. Okay.  So the answer to these questions is, if the graviton exist, the answer is yes. And this is maybe not the first thing you think but it is simple to work out. Okay. So this is a finding diagram where I have matter, and the matter is exchanging little gravitons. So there's a little space time ripples flying around. And the energies that looks like exactly like the thing I just showed you it looks like a Newton potential that talks that puts some interaction between the two masses in the picture. This this can generate entanglement and so you can go forth and look for a bell violation in an experiment with two masses. So just to give a simple counter example people have have long used equations like this so this is the metric this is the Einstein equation, where on the left you have space and curvature but on the right you'd have the quantum stress energy tensor of all the matter. But you put these little brackets which means you take the expectation value so now on the right side, this is a classical object this is just the average energy density in the universe. So it's easy to work out that if, if this is actually the equation for the universe, then, because this is an averaging operator, you can't actually see details like the superposition of the mass. So in fact in this, in this model you will not be able to entangle two masses through gravity. So this gives you a set up for the experiment, you know there's two clear options, if you want, and you will rule out one or the other. Okay so now I want to get a little bit more into how the experiments actually work with this sort of overall picture I'll talk a little more about these details models at the end. But how would you actually think about doing an experiment like this. The first thing you have to know is a little quantum information theory which is, okay I'm testing our two things entangled so how do you actually do that. So this is really where Bell comes in, so Bell really invented the way of doing this. You know building off of Einstein and Rosen and Podolsky but I would say they'll really hammer this down for everybody. So the classic way of thinking about this is the following so I'm given a state row. So this is the density matrix this is a little general way of writing it, you can think of row is just the wave function. And the question I want to ask is, is the wave function of the two masses, so the two masses are a and B is the wave function a product, meaning all the information in a, all the information in B has only quantum, sorry has only classical correlation that's what that would really mean. A non example of that would be like the singlet state of two spins that you learn about in quantum mechanics. So what Bell basically showed was that if you, for example take two qubits. There's some quantity w, which in this example is some product of the spin of the one guy in the spin of the other guy if you're doing two qubits. There's some operator whose expectation value will be will be positive. If the state is not entangled and it will be negative if you're in a specific entangled state. There's a lot to swallow. What, what this basically says is, if two systems are entangled, then there's going to be some correlation. So this expectation value this is a correlation function of these two operators. You might hear some scratching the back because my cat is randomly running around with the spring everywhere. What's going on here is in the, excuse me. So, if the state is classical it's not entangled, there will be a certain level of correlation allowed by classical mechanics. But in quantum mechanics you can have correlations between two objects which are actually stronger than anything allowed by classical mechanics, and Bell makes that very precise by local hidden variable models. And this is the essential statement. So, so when doing a belt test what you want to do is try to prepare your entangled state, measure some operator like this, and check if the correlations violate one of these classical correlation inequalities. That's basically exactly what we're going to do. So how would you do this in gravity. So this is a beautiful idea. So this, this proposal really was done by a set of bosses group in London. In, in, I guess, 2017 and time flies. There's some earlier work that this is closely related to by these people. This really goes back to page and gelker in the 80s. But these guys gave a nice like pretty concrete proposal. So, so what do they suggest so they say okay what do we use for the masses to make them little diamonds, and these diamonds have a nitrogen vacancy center so these exist, these are very useful for many things. But for the purpose of this talk what it is is it's just a piece of mass, and it's going to be pretty big like nanogram. And then mass has little spin half in it, and it's been half couples to the motion of the diamond. So, you can move the, you can move the center of mass of the diamond around by hitting the spin. So basically what that allows you to do is they make a superposition of the diamond by just shooting this thing through a Stern-Gerlach experiment because the magnetic field in the Stern-Gerlach will couple to the spin and therefore couple to the mass. And so what they propose is take a pair of these diamonds and take each one of these diamonds and shoot each one through a Stern-Gerlach apparatus. And then I have a diamond here superposed in two places. I have a diamond here superposed in two places. I let this thing free fall to my lab to get rid of noise. Okay, as it's falling, these things talk to each other gravitationally. And what you can work out is that the wave function of the two diamonds becomes entangled. So, mathematically it looks like I start them both in some initial state I call it left left here. And then as they go through, you become some entangled state where you have super positions of the, they're both on the left ones on the left ones on the right and so forth. And you can see that sort of the amount of entanglement is captured by some phase that shows up and this phase is given by exactly the same scaling I showed earlier. So it can be sort of order one meaning visible, you know, with nanograms micron seconds. Then what happens is, at the end, you have this entangled state of the two diamonds. And what you can do is now test this entanglement through literally a belt test, the belt test in the typical sense with two spins because you have spins in each diamond. So this is really a beautiful implementation. I mean, it's a very conceptually simple, in some sense, probably the simplest conceptually way of doing this. That's fantastic. Okay, the problem is the numbers you need to actually do this. Okay, so to actually do this. There's a number of difficulties one is that you need to measure both systems so a belt test even with spins was originally challenging. You have to measure two systems at exactly the right time and you have to do it fast enough, you know there's no faster than light signaling and so forth. In this system, the entanglement is extremely weak and the system is noisy so you're really trying to extract a tiny weak violation of the bell inequality, you know that is sitting around in some very noisy system. That's okay. What really makes this hard actually is more mundane experimental issues. One is that I need a huge magnetic field gradient and that's because I need a magnetic field gradient to operate the stern Gerlach to split the wave function. Maybe even, and by very large I mean you know a few orders of magnitude bigger than anything that exists currently. Even harder probably is you need a pressure, you need environmental isolation which is exceedingly good so a few orders of magnitude lower pressure than say interstellar space. So, I don't mean to say that you can't achieve these. People are for sure working on these things for many reasons, but this experiment is some years away from being done at best in because of these issues. So, it's a really nice concept and maybe it will be the way we learn that gravity is quantum mechanical. But I think at this point it was worth thinking through maybe there's there's other ways of doing this. So I want to briefly mention a way that we propose this is really the only slide on my own work here. This is an idea that Jake Taylor Holger Mueller who's an experimentalist at Berkeley jakes and theorist at Maryland. This is something we had, which we think we basically eliminate all of these technical difficulties. So it's got a fancy name we call the interactive information sensing the experiment in some ways is simple and the interpretation is hard. So the experiment, let me just describe what we would actually do. So the experiment proceeds like this cartoon. So what I do is I take a massive pendulum so this can be like those sort of milligram scale hurts frequency pendulums I showed you. I just hang this thing there and I take an atom and I prepare the atom in an atom interferometer so an atom interferometer is something where there's a laser field, and I can put the atom in different wells of the laser field. So in particular what I can do is, I can take two wells of the laser, and I can put the atom in a superposition of two positions. So this is just the shreddingers get this is exactly the same as the superposition of the diamonds. It's just now with a very tiny system and Adam, since with a very tiny system I can actually imagine this Adam sitting there for a long time and in Holger lab in Berkeley that he keeps them there for on the order of a few seconds. In this nice quantum superposition. Okay, so now what do you do so you so you take the pendulum you put it there say in the ground state, you put the atom, you prepare it in a superposition of two locations. And now what happens, well, well, if the Adam is on the right side, the interaction gravitationally between the pendulum and the Adam will be, you know to want to move the, the pendulum to the right, and if the Adam is on the left the pendulum to the left. And so that's what's shown in this picture. So there will be some extremely tiny, but finite motion of this pendulum, and the pendulum will swing just very slightly one direction or the other. And now what this really does is it displaces the equilibrium of the pendulum and so what happens is now the pendulum will sort of swing with the period set by the pendulum. And the, and the idea is to wait for different amounts of time and measure the state of the atom. So why what's happening is, as this evolution proceeds here in this middle picture I have an entangled state of the Adam and the pendulum right the information is shared and the whole wave function of the universe is in two branches pendulum goes to the right Adam on the right. The pendulum goes to the left and Adam on the left. Well these are entangled, if I look at only the state of the atoms, what I'll see then is a collapse of the wave function of the atoms, this is called decoherence. It's very well understood phenomenon by now, there's many experiments sort of like this just not with gravity, where you see exactly this, I generate some entanglement between two objects, I measure one object and I see that it's a wave function has decayed. Concretely, you would see a loss of contrast, if you do an interferometry experiment with this. But for the purpose of this talk the main point is you only have to measure the atom. You don't have to do some horribly difficult measurement on both things at the same time. The fact that you're only measuring the atom, and the fact that everything here is periodic in time with a slow frequency is what really basically enables this to be hopefully done. Okay, it really will eliminate a number of technical problems so for one thing. Okay, so let me. Good. So, so what's the real statement here is this really like a kind of a bell test. Basically the answer is yes, although you have to make a few caveats so I wouldn't try to read this theorem I just show this to say that we, we made it come precise. What I mean is that if you see in this atom, the collapse and revival and collapse and revival of its wave function, and you know that it's happening because of the pendulum in a precise sense. Then you can show mathematically that this is only possible if, if there's entanglement being generated and then destroyed and then generated and destroyed. And this has has to do with the monotonicity arguments and so forth but the output though is that what this means is that you can you can sort of do a bell test in the system. So instead of measuring two systems at one time I measure one system at multiple times. And I have to make some then assumptions about the interaction, but very weak assumptions. So essentially this is a bell test, it does essentially the same thing as the previous experiment. But it is substantially more robust and noise and the reason it's more robust and noise is because super positions of large systems quantum states of large systems die, they, they're killed by environmental noise is very rapidly. Here we make a very tiny superposition this mess it barely moves so actually this thing can barely be destroyed by the environment. So what we really need is a long Adam time along Adam coherence but this already exists. So, so we were sort of using a different technique and I'll just show. I'll flash this slide I think you should probably read the paper if you want to see sort of really the experimental details about why we think this could work. I'll just say the punchline is this looks like you should be able to do it. So what you need is an atom interferometer with, say 10 to the eight atoms so I draw with one atom but really you have a little cloud of, you know, nearly a billion atoms. But these exist all over the place now. You need the atoms to be around for about a minute. So this is maybe an order of magnitude longer than state of the art but nothing crazy to propose, you know, building. Yeah, these, these numbers all are just to say, at room temperature so you don't really need a lot of isolation, you can in on paper do the experiment so so Hogar's lab at Berkeley is starting to seriously think through doing this. But we're quite excited that maybe you could just experiment in, you know, the reasonably near future. Okay, so just to finish, I think I heard 40 to 45 minutes so I'll just last five minutes or so. My own natural state which is theory. You know, suppose we did this these experiments so maybe we do ours with the Adam and the oscillator. Maybe we do the bows at all with diamonds. There's been a number of other proposals that are related. Somebody's going to do one of these sooner or later. So successful. We can already see we can show quite robustly theoretically that what this demonstrates is that gravity is causing entanglement, gravity can generate entanglement. That's the concrete experimental state. So the question now is, okay, who cares, you know, suppose you knew that was true. What did we learn about gravity I mean okay and angle things very cool. Great. So did I learn anything about the gravitons I learned anything about string that I did I know of Penrose's thing about the wave function collapsing is true or not. And that's that's sort of I want to sketch what is known the partial answers to these questions in the last couple minutes of the talk. So I mentioned this before and I like to start with this. The first thing to say is that you can imagine ruling out some funny models. I talked about the semi classical gravity model, and let me just say it again. So many classical gravity would be the metric response to the quantum expectation value the average of the of the stress energy of the matter. And I made the argument before, which is that this this has no quantum information that this has deleted all the quantum information that's in fact why you take the average you don't want to deal with the if the universe really operated under this equation. You would not be able to see entanglement for gravity. So you would do the experiment. And what you would find is that the masses never get entangled. Now it's hard to say for sure that you've done that because if you never see them get entangled probably your experiment just wasn't quite good enough yet. Okay, but so you have to really convince yourself that was the answer. If you did see the entanglement. This model is just out you can. It doesn't make any sense. This model has theoretical problems also but you know, that's a whole other talk. There's a kind of more modern and I think interesting thing and this is an open question so I would encourage people young people, especially now that I'm getting old to think about this. Gravity is an emergent phenomenon. So this can actually mean a lot of things. And so let me give two sort of pictures here. So the first one is in string theory. There's the ADSDFT correspondence. And, you know, there's a whole lot of story about that but the short story is, okay, what if gravity emerges in that way gravity is some one wavelength version of string theory. In that model we know by construction that the answer is it goes as follows at high at high energies you have strings at lower energies you have gravitons and therefore by everything I said already, you'll see the entanglement the gravitons will just mediated Newton interaction and so forth. So, so if you do the experiment it doesn't mean string theory is true but if you do the experiment, and you don't see the entanglement I guess you would rule out string theory that would be one way of saying it. If you did see the entanglement it doesn't mean that you can go back up the chain though. So this is one way in gravity would emerge and basically give you the entanglement, you can imagine though that if gravity emerges if it's the long wavelength limit of a hydrodynamic model with lots of little degrees of freedom. So, if you took a typical model like that, you would actually expect that there would be no entanglement you have lots of little particles or whatever makes up the gravitational field. You know, hitting these objects.  So, you know, this is a very heuristic that there's no favor that really goes into this, you'd need a microscopic model, but I do like to suggest that, you know, maybe these entanglement probes are a way of sort of thinking about distinguishing ways that gravity could emerge, by by characterizing whether or not they can produce entanglement. But really, in my heart what I want to know about this gravitons you know my prior is the graviton exists and what I'm doing here is I'm proving that it exists that would be what I'd really like to claim. But that's a high stake claim and you have to be very careful if you're going to say such a thing. So let me show you to finish just what is the statement about graviton model in this experiment. So what is for sure true, and I've said it a million times now is that if the graviton exists, it will generate the entanglement. And it's easy to picture how it happens you have the two masses when you superpose one graviton fly around. Everything is quantum mechanical and beautiful works just like quantum I like for dynamics. And I get the entanglement. So you might think then if I saw the entanglement that this would mean that the graviton exists but this is wrong right that the implication is only from the left to the right not backwards. So you have to actually ask this question. If I see the entanglement do I necessarily know it's a graviton. And really what you want to say is under what assumptions would I know for sure that it's the graviton. Okay, so there's some partial results but this is an open question in my in my opinion. Here are some partial results. So, so if you see the entanglement in the experiment, there's this beautiful paper by Alessio Balencia and a bunch of people Bob walled included, which shows the following thing. Suppose you can do the experiment. What you know for sure then is that you can generate entanglement with the Newton potential the one over our law. So that's an a non local force. And so that would mean that you could actually potentially signal faster than the speed of light. So that would be a problem. So how do you resolve the problem. Well, you have to assume something beyond just entanglement through the Newton interaction. So in the paper that if you assume that there's quantized metric fluctuations roughly speaking, little graviton, you'll resolve all of these fascinating life problems. And indeed this is the way you don't sort of typically you think about resolving fascinating problems you just put quantum fluctuations. There's another related paper which is a similar statement this is much more recent now where they basically show that if you see the entanglement and you you know that the force cannot be mediated by a classical gravitational wave. So you would say rule out some weird model where there's just classical gravitational waves somehow doing all these interactions for you. But none of these are really nail on the coffin, you know you do the experiment, you see the gravity and you can imagine finagling with, you know, messing with these assumptions, you can imagine a model that would get around these kinds of the conjecture. And in fact this can. Okay, so the conjecture really kind of see me you want to make it in any field theory, where you get the Newton interaction at low energies. That that field theory definitely has a massless spin to state, meaning it has to grab a thumb. So you'd really like to show something like this and this is an open question. So certainly I work on this from time to time and I'm sure other people have thought about it it's not a simple problem. The answer is probably wrong. You know for the sort of connoisseurs in the audience that there's an there's an interaction you can imagine which would mimic all of this graviton stuff, which is a scalar graviton you can imagine a scalar field which couples to the trace of the stress tensor. And I think that would actually probably do everything else that's in this paper but that would reproduce the entanglement generation in the experiment. That's an interesting question, you know, do we know that the graviton exists if we get the entanglement. I mean, morally probably yes, but you know, formally, it's really not proven, I would say at this point. Nevertheless, this is sort of why I'm doing this.  No, can you do an experiment where it would tell you that the graviton exists. Yes, it's kind of an interesting philosophical position. If you wind up in in that, in the end, you know, well we know that the graviton exists but we can't directly detect it. So does it exist I don't know I mean that's one for the philosophers. So good so I'm out of time and actually did this on time so so let me just conclude. So, again, if you know you zoned out through a lot of that the statement is in some way simple. You know, if gravity is quantum mechanical in the sense that it's a quantum field theory. If you want to be really precise and the statement is that space time perturbation metric perturbations are truly a quantum degree of freedom just like the electromagnetic field. You can generate entanglement between two masses to the gravitational interaction. And then the really the more bold claim in the talk is that you can actually test this question you can you can get a binary answer is this true or not. And you can do a tabletop experiments and the reasonable near future. And so I'll leave some open questions. The question is this one I just went through if we see if we did the experiment, we see the entanglement, we're sure it's from gravity by ruling out all the other possibilities and so forth. Do we know that graviton exists. And, you know, just again to hammer in that this is really an open question you know, for sort of more high energy people, you can think about gravity and two plus one dimensions as an interesting counter example, potentially right gravity and two plus one dimensions has no graviton and you can definitely entangle masses. So, you know, think about it. The question is, is there a smarter experiment to do. You know, I nobody's claiming that we have the optimum things at this point. And there's still time to make something before anybody actually achieves one of these things in a lab. So I put this reference here we wrote a long review paper a couple years ago, which goes into a lot more detail about the models, the various types of gravity that you could test and so forth. And I would recommend you to check that out if you're really interested in this. In the meantime, thanks very much for having me and thanks for listening to the stock. Thank you very much. Dan, now we're going to spend some minutes with questions. While we check if there are any questions on YouTube I do have a question that Roberto who had to leave early has for you. He asks, can the quantum behavior of gravity be nonlinear and in that case, can that feature make it harder to use the standard model of the standard quantum mechanics to build experiments. Yeah, this is a very interesting question. This is a very nice question. Yeah, thanks. So I think I even put a backup slide for this. The answer is baby. And yeah, this is interesting. So let me first actually show a, so there's these semi classical models right so this model actually is not well defined by just this equation. You might wonder, okay, well, this tells me how the metric evolves but how do I know what the matter does the matter there's a state of the matter and the state of the matter has to evolve under some equation and like okay what happened. So if you put this thing, if you assume the Schrodinger equation, this, this is a horribly broken system it has super luminal signaling and all kinds of stuff. So in fact the only way to make sense of this, and this is a recent sort of idea is you have to make quantum mechanics nonlinear. The quantum mechanical evolution has to be nonlinearized. So this is a slide and maybe I don't have time to go through everything on here, but this is a concrete proposal to do that. So now what you do is you say quantum mechanics, in addition to the Schrodinger equation. That's this first line has these extra terms. And what these extra terms mean these are nonlinear terms what they mean is basically that you think of gravity in this model is measuring the matter, doing a computation which tells, which is going to tell you gravity, the computer that is gravity, you know how to move objects around. And so these terms are basically a noise. So these are an inevitable source of noise in a model where gravity would be classical, coupled to quantum matter.  However, then it makes the test different as, as the question was, was hinting at. Now you have a nonlinear quantum mechanics, and we know things happen in nonlinear quantum mechanics. For example, these noise terms will cause heating in systems that you wouldn't expect. It'll cause some irreducible heating rate of anything. And so you can start asking like okay, you know, we have very sensitive systems they're cold for a long time, can we rule out this heating and therefore rule out these kinds of models and you know this is a whole thing and lots of people are writing papers about this right now actually so it's quite an interesting possibility I would say. Thank you. Any question from the audience here. I can, I can, I have to ill pose questions. Thank you, Dan, for that nice talk. The first one is like when you say this type of experiments might be performed in the near future. Could you please define what you mean by near future. Yeah, I mean it depends basically how optimistic I'm feeling on a given day. I would say that, you know, this experiment is sort of original proposal. One of the people in this paper is Andy Karachi, who would probably be actually doing a lot of the experiment.  So I think they're thinking you know 10 plus years. I need these low backing pressures and stuff. So now, to put my optimist hat and, you know, obviously this is biased. This thing, you know, we think you could do it.  But at least order of magnitude level this looks like something we could do few years, let's say. Thank you. And then also regarding this slide. So sorry, I got lost a little bit but but but I was thinking like if you prepare this entangled state. I mean, when you measure you collapse it so as I was thinking like and actually this is, well, you already at the beginning. It's just, it's a microscopeical, let's say experiment but but it's still big in that sense. So my question is, could you just repeat again how this will work because I think like as soon as the pendulum starts swinging, then you just lost all the quantum mechanical behavior I would say, or I would think because the wave function will indeed collapse and then you just measure and then I don't know. Could you just go over this again. Sure yeah yeah this is a little subtle of an experiment so good so you prepare the atom in the superposition the pendulum starts moving. And I drew it this way because this is exaggerated but the pendulum really barely moves in one way or the other. So if you think about it as wave functions, the pendulum's wave function, you know, just barely doesn't overlap. Okay, okay. And so then this causes, if you now measure just the atom that will cause a tiny amount of decoherence in the I see so it doesn't collapse like okay. So that that yeah so I didn't explain this picture but that's what this graph means so this is saying sort of the atoms coherence, if you want. So that one in some units and then it goes to some small value and back up and some and this value is set by the Newton constant so it's a tiny you know this is a highly exaggerated graph. Okay. Oh, thank you. Sure. I have a question that is probably more philosophical so let's suppose that suppose that instead of having a gravity tone right we did the real theory of quantum gravity is really just that space and time are discretized and then we go into the realms of theories like loop quantum gravity or those things. So you wouldn't measure anything right. Yeah, it's a hard question I don't know if anybody has precisely stated anything about this. So, you know it would you'd have to actually calculate it, it would depend on the detailed microscopics and in a way I mean it's not the same model but you know it sort of gets into this statement. I can say that Carlo Rovelli wrote a couple papers and is very interested in these experiments, and he wrote a paper saying that you know his expectation is you would see the entanglement and loop gravity would predict that you would see it and so forth. So according to him at least I think that's the statement how exactly that works I'm not I'm not sure. If you imagine that that the space time is just sort of broken up in a little discrete chunks though. I mean, to me, that would suggest sort of might have some anomalous eating it seems very hard to view that as like a coherent quantum system but you know, it should be studied more detail probably. All right, let me check. Do we have, I have, I have one one question regarding your, your last discussion with Alejandro maybe you could go back to that slide. Right right so so so this is this, I find it very, very interesting I mean the conversation you just had with with Alejandro because initially when I saw this I thought it was some kind of like quantum. experiment right initially I thought that you would be measuring a like a displacement of the pendulum but the whole point is that you're not. Right, yeah, the whole point is that you, I mean I don't know if it's possible to measure that, but that you're not measuring the displays that the oscillation of the pendulum. So the main effect is what gives you this a. This the coherence and recoge right this kind of interaction with them. Okay, great. So, so, so then in that sense, what are your main sources of background when you're doing this experiment. So, this is a difficult question that, okay we're still thinking through and probably will require the experiment to be built to really know the answer. I can say things that we worried about and why we don't think they matter.  Okay, so what what are the main problems you know you would have gas particles hitting everything. That's obviously a problem. I think more importantly than the gas is you would have black body photons everywhere. And both of those things you would normally worry would be a problem. So if if the pendulum was super pose say in a large superposition, that will be a huge problem that any time a gas particle hits it or a black body photon gets absorbed or something that will just destroy the experiment. Like this is kind of like the under the hood. The amazing thing about this is, you know, this the superposition in here that the distance is like 10 to the negative 18 meters or something. It's a very tiny position. And it's much smaller than the wavelength of any of that stuff. So, if a black body photon hits it the black body photon can't actually tell where the mass is if you want it can't cause any decoherence. And so in that sense, those noise sources don't actually in principle affect this. I think the more realistic problems are more annoying you know they're things like, I can't put the atoms too close before there are interactions between the surface of the pendulum, you know, which is some metal say, and the atom, things like that. So that you know really set some design parameters like you have to put the atoms at 100 micron at least and things like that. Right because you have the cool of interaction at the end. You know exactly. So, right so you know luckily atoms are remarkably neutral, it turns out. You have Van der Waals interactions, you know you have to really so these are pretty yeah there are things like that that depend on sort of the details of the realization. Because I was thinking about the previous experiment the one day like the Stern Gerlach. Yeah, and and there you can more or less like control the backgrounds in a way because you can send one diamond only. And then the other right so then then I can imagine okay you can reduce some background there right, but on the other in the other one I can, I wouldn't know how to remove the background. So one analogy with that is what you could do is you know you can just operate the atom without the pendulum and vice versa to get rid of some things. I but I do agree yeah in some way this is the background here are going to be harder. The thing though with this is, yeah you can you can understand the background, however, the signal itself will be destroyed in the experiment that this is what I mean by you need very low and this is related to this comment about black body photon. You know, as this proceeds, you're talking about nanogram objects separated at 100 microns or something. And that that is an extremely unstable quantum mechanical system. I mean a gas particle hits that and that's what position is gone and now you have a classical ensemble and you'll see nothing. So, so yeah, I just just to say. It's a really fundamental challenge in a setup like this. Right. No, thank you very much. Sure. I have another question that so when you are getting to this so sensitive experiment so you can measure those type of distances. Once you end up measuring maybe some other new physics or I don't know. Yeah, what a particle hitting your system and. Yeah, that's massive. That's right so actually this this system in Holger Mueller's lab is originally designed as a measurement of fifth forces you know new light degrees of freedom the couple amass to to the atom. So, so we're really piggybacking technologically off of that and this would just represent maybe an order of magnitude better sensitivity in some way. So you can definitely imagine using this to look for new things. So fifth forces are typical one you know we have done lots of work on looking for dark matter with this kind of stuff. Yeah. You know what this signal is kind of unique. This is a very, you know, human engineered signal if you want you really do a lot of controlling quantum mechanically and so it's hard to imagine something randomly doing this, which is an advantage. But the systems in general. Yeah, indeed they're so sensitive. Looking for new particles is obviously something I do in my spare time now with these systems. Definitely a lot of things to be looked at potentially could be seen. Excellent. Can I ask a question. Yes. Well, first of all, I apologize for coming a little bit later was lecturing and so I got, I would say least than a half of your talk done but still I find it fascinating thank you very much. So first a comment and then maybe a question regarding this last point of finding new physics. I can imagine a Holger also made maybe he thought about doing some like equivalence principles, principle check, because maybe you can you can arrange your atom, you have there in the probe and and try to build on the charge conjugate version of that and see if it couples in a different way gravitationally to the pendulum. I don't know. Maybe they've thought about that idea. But that's a crazy thinking that was my comment. And the question was regarding this experiment with the pendulum. All you care about the pendulum is its mass, right, you don't care very much about its constitution or what kind of muscle is that right or not. Yeah, that's exactly right. You need that it's periodic system, other than that, it doesn't matter. Okay, because I was wondering because one of the problems regarding the noise I think you mentioned it briefly was not only the cool of interaction I guess that those scales which are very tiny customer interaction might spoil and be very important there so maybe it could be a good idea trying to explore some kind of a pendulum that could somehow shield you from the customer interaction. Would that be a good idea. Do you think it would. Yeah, definitely. So I'd be curious to know if you have in mind a way of making the pendulum specifically to do that. But what people have done and what we assume we will do is put a shield. I wish I had a slide for this but there's a nice experiment in Vienna, last year which does exactly this so what you would do is in this picture, you literally put a superconducting sheet between these things and you can use that to screen the chasm your force to some level. You know the other thing you would do is of course you just put the atoms far enough away that you know the chasm your force goes down like one over our to the sixth or seven. And grabby's one over our for okay well.  But yeah, in practice, you would shield it. I do wonder if you have some idea for what you can do to the pendulum itself. I think I might, but I would need to to read in more details I don't know if in your papers, you have information about this. I will look at it but I do have some idea but but still is it's, I don't know if it's feasible to construct a pendulum like this it's it's regarding to these new states of matter. There are some logical insulators in particular there are some proposals in which you could tune the customer force between a different materials actually either making it positive or attracting. So, that's a good interesting. I did not know that yeah I'd be happy to talk about that actually few. I will look into your papers and write send you an email about it. That's it. That those were my questions and comments. Thank you very much. Thanks. All right, so thank you everyone over YouTube for watching this seminar and we encourage you to subscribe to all of our social networks and follow us to be up to date for the next seminars and we once again thank Daniel for this amazing seminar, and we'll see you all soon. Thanks again.


Hello friends. This is the Simply Guy line of beakers we have from a company called UPC. They're from Southern California. It's all American glass, which I know a lot of people prefer. This is our donut style version of the Simply Guy. It's really sturdy, very very basic and not too flashy, you know, but the price the price cannot be deep for what it is. It has a diffuse down stem and this kind of unique donut style base down here. I'll go ahead and pull on it to show you what it can do. A very classic design and it for a reason. It works very well. This is the classic beaker style.  Here we go. That's awesome. And this one for someone that wants a little bit more flavor to their piece. It's got a zong style neck and a bubble base. It looks really cool and it works like a charm. Anyway, that's the Simply Guy line from UPC and we carry them at Smoke Cartel. Thank you guys.


A very important aspect of meandering rivers are the flood plain deposits. So when you have a river channel here and there's a normal water level in here, all of the sediment transport that's happening associated with the rivers within the channel and you often have plants in post-Divomian world, right? So you have plants growing on the outside. So here's some trees or bushes and things like that. And so a lot of times the flood plains have soil development between river floods. But through time sediment accumulates in the river channels, and there's erosion here, but almost all rivers are subject to floods. And when the water level goes up, there are two things that happen. One of which is that the amount of the cross-sectional area that the water is flowing through expands dramatically. And that allows the water and causes the water to slow down. There's more friction with the bottom and there's much broader flow. So the same amount of water flows through a given area at a much slower rate because the area, the cross-sectional area is much larger. So when the river goes from being confined to within the channel to exceeding the channel bank, there's a sudden slowdown in the flow speed. So you decreases rapidly. And we know that when the flow speed decreases that causes deposition and that deposition creates a natural levee on the side of the river. So that produces a levee, which is the high, a high deposited by the sediment just outside the river channel. And because the deposition rate is so fast, there's not very much erosion on the upstream side of the bed forms. And so you often get climbing ripples. And usually that grain size is relatively low because the course of sediment, even in a flood time, is going to be confined to the channel. And so usually you have, say, a medium sand near the channel. And because the flow speed is going, slowing down the further you get away, it'll find away from the channel. And eventually the water ponds, and that actually leaves a lot of mud behind, which is one of the problems when you end up with floods in towns is that the floods can bring in a huge amount of mud. So the signature of a flood deposit would be, for example, a soil with sand deposited on top of it that finds up to mud, and then you redevelop the plant communities and the soil formation processes.


Good morning one and all we're here from dr. Ganesh's ICT project, which is a loka cart android application So before we go into the details of our project We'll be giving you all a slight overview of the loka cart android application So you'll understand exactly what it is about So, you know farmers face a lot of issues in getting their products across to consumers One of the key issues is the logistics involved in these Produced transactions as in a farmer has to go to a farmer's market set up all his goods He doesn't know what sort of quantity he has to carry of what good because he has no idea of the demographics of his market So in order to solve this issue or at least streamline it we created an android application that loka cart application Which we'll proceed to demonstrate. So this is the android application now There are different categories of products if you swipe left you will be able to view the different categories according to Which the products are organized. This is a client application. So there are three parts to the loka cart project We haven't developed it. It has it's a huge project. So obviously we aren't No, this is for the yeah, this is for the customer for the customer for the for you So you are viewing the products listed by the farmer. There is an admin application That will be operated by the farmer support group So farmer producer organizations and farmer support groups other people who help the farmers list their produce Why is this 2 kg of stock? Why 2 kg, some are 2 kg? So that depends on the organization as per what they want to list So if the minimum quantity they have of strawberry is 2 kg and they want Yeah, these are farmer listings. So we asked them based on their options. They have listed it this way So we'll proceed to add some products to our cart and place an order just to illustrate the flow of events So location is what we are working on right now. So he'll explain about location. That was his task Now so if they took a key of whatever Apple is not available in power It is available in Borivali. So that depends there will be a number of organizations He'll proceed to illustrate how you change your organization So these are number of organizations registered on this application So there may be some organizations operating out of power. There may be some operating in power So the idea is the organizations add members depending on their location and the member location I want to know how farmer gives his goods on your web There are groups of farmers called farmer support group of right so groups of farmers have farmers club Yeah, Abhinav farmers club approaches us to list their organization on our application For me as yeah, there's an online form Actually that that's very outside the scope of our project. So it would take a lot of time to a fee No, no, no to start with that. Okay, so they list what they list their products So their organization is listed as a part of their organization. They are on an administrator app as an administrator app I have the admin app if you don't forget it. No, what do they do? So they basically list their products. So these members when I place an order it goes to them Me and he are part of that Abhinav farmers club. I want to sell mangoes at 10 rupees He wants to sell it at 11 rupees. No, that is the reason they have a farmers club Club The organization sets the price list that is the point of forming an organization So these economic issues are avoided. So that is why a group of farmers come My mango is better than his So it is your mango. It is not my mango. It is not his mango. It is our mango So the idea is they have There's no group cannot be our mango I have put too much effort in my farm. I brought some fruits and mangoes So sir they Result How I can So the simple solution to that is if you disagree with the views of your organization You go separately and set up your own organization So you set up a single farmer but we won't be able to accept you as a single farmer Because an organization would be able to supply many more consumers Right. So as an organization I want to sell at 10 rupees That farmer is saying my mango is better. I am selling at 20 rupees Fine. You set up your own organization. You get a group of 20 rupees farmers And if you are able to supply the quantity Then you might as well form an organization So then actually your application is not meant for farmers It is meant for the middleman So that is the idea So that is not the middleman So that is not the middleman So that is not the middleman So that is not the middleman So that is not the middleman So there is no middleman They are getting the direct transaction You don't know who is the director Abhinav Parmer Club could be Reliance Ka Chamcha Sir Abhinav But you have no idea who is Abhinav Sir they are farmers These guys have gone and met them In Bombay there are so many slums Where 30% of the slum members are fake Because builders want to do SRA So don't talk to me about that Anyway it doesn't matter I don't agree with it But take it to the outside Okay So they list Yeah Why are they listing 2KG? They list 2KG because that is according to their preference As I mentioned their minimum quantity might be 2KG I want to As a farmers club I want to sell 1KG of apples and 2KG of apples Can I do that? Yeah you can do that So there will be 2 elements You can list an element here Apples 1KG 2KG So that is possible So finally we are working only on this Yeah So this does not tell me where it is available As in Where is this 1KG mango available Out of stock?  If I am part of this area This is Abhinav and you are from Bindra Abhinav He wants to sell me You can be part of both organizations Abhinav doesn't see Abhinav He doesn't see Abhinav He doesn't see Abhinav He doesn't see Abhinav He doesn't see Abhinav He doesn't see Abhinav You can change your organization As and when you want You want to You mean I want to buy Only one kilo of mango Ten people are ready to sell me One by one Sir but that is the point You are loyal to your organization If you want to view You are free to view I am loyal to mango only I am loyal to mango only So it's one button click to change an organization And you view all the products of that organization Sir the entire point of e-commerce A customer never really ends up buying What he wants He buys 5-6 other products as well I do everything on the net I say They give me a lower price And then ten people are there Right sir But this model is different This model is not based on real life So, they have met people in real life, there are people implementing this application, so they have asked for these features. This is not Loka card, this is Reliance card. It is only meant for Reliance to get things from there and sell it to people. And barricadar people from doing it. Reliance was real, Reliance to Reliance 3 Ajay Kao. So, we will proceed to the tasks that we have accomplished on this application. As a part of this internship, I have been assigned three major tasks, making automated test suite for this Loka card application using Espresso. Then there are some limitations for automated testing. So, we have to do manual testing for both because Espresso is a one-app testing. We can't do testing with two apps. We have two separate set client and admin. The third part was integrating GPS in Loka card client application. So, you don't have any interconnecting apps? We do. Loka card client app and Loka card admin app. Yeah, but they can be tested separately. They are not working separately. This is an order placed on the client app will go to the admin app. Because the order placed when you have to process the order, the admin part use the same app, right? They have an entirely different framework, they have a different feature on the app. So, they have different data sharing. Moving on Espresso framework. Espresso is a UI framework which just performs three basic operations and for a single test case. And we can write test cases according to it. It's find a... It's automated testing. Yeah. It's automated testing. Okay. Test plan. Test plan. One test case, ten test case, five test case. No. Like invalid input. For example, in feedback form, some are... Let's talk about RootWallet. I like this one. RootWallet is... Which one? RootWallet. Hmm. But... That one. Yeah, but in checkout, if... So, be the app and tell me what you requested. In checkout, in add to cart button, user can add... There are limitations. He can order up to 999 ordered. But if... What if... Yeah. What if he tried to enter more than that? App... App suddenly... App may be... Like 999... Minimum... Minimum... Minimum... Minimum... Minimum... So, it's... The features have been integrated based on the organization's demand. So, what they did was, after we made an app, we went and met all the organizations. You? No, like the team. Yeah. Me too. Abhinav. So, Abhinav Farmer's Club... Mumbai Solins? Mumbai Solins and Arya Sanskriti. There are three organizations. They went and met them. So, when they spoke with them, they got a number of requirements from them. If you buy 100 rupees, you will get it free. Abhinav. Okay. Okay. Okay. Yeah. In a two-card... There are limitations to up to 999 quantity. But what if a user entered more than one? It may be... App even crashing... Using... Yeah. But not 999 rupees. He meant 999. 999 quantity. Yeah. So, what's happening first? So, what's happening first? So, what's happening first? So, what's happening first? So, what's happening first? So, what's happening first? So, what's happening first? App was crashing. Yeah. So, what's happening first? So, what's happening first? Yeah, the same. So, for that, it's all about the taste. Yeah. So, I'll show you how to simulate it. So, I'll show you how to simulate it. So, this feature... I write a taste case, which enter in a two-card more than 999 and checks if it works or not. And based on that, test case passed, there are many 16 or 17, I think, but it is not individual. For example, for dashboard activity, I write a test case which cover many test cases. Should I show demo? Something which cannot be done. So, for example, there is... How do I know this is just in a company? Yes, I have a demo. Do you run a simulation on a laptop without a button? No, no, I don't run a laptop. Tell me how they are complete? Do you run a simulation to show you the test cases? Autoptically. I don't see it. There is no time. I assume it's only a simulation. How do I know they are complete? It returns after all test cases are completed. You develop 16 test cases. Your job must test an app. You deliver 16 test cases to Professor Ganesh. How does Professor Ganesh know that you are testing the app? The complete testing of the app was your job. How does he know the app is tested? Complete. Because there is no way that you can do everything. You have tested everything. Prove it. But how can... How can we... Do our job as testing. There is a testing methodology. So now we will see for the test cases that we are playing a real test case. What box? This is the right box. Input you cannot tell me my input on the app. That cannot be the input. For any test case to be developed. We... Your document. What was your document? Did you have a document? No, just I have... For manual testing I have just made a excel sheet which shows all bugs in that. All what I bugs find out. You have not understood. Test Microsoft Excel. Will I do it? I will not do it. Okay. Automated or manual. It cannot be done. Okay. For testing you require a document. What was your document? If you did not have a document then the answer is I cannot certify tell Dr. Ganesh or Dr. Ganesh will not know whether I have done the job or not. Testing is like this. There is a document. There is a list of features. Then I have to say feature number one. Feature number sub feature. This particular form has got 10 elements. One element test is this. Second element test is this. Third element test is this. If I do not have that, I cannot say my testing is complete.  I do not rely on human beings. Okay. If... I mentioned in one excel sheet that all the... What is the test case? What is the test case for? What is the test case? I have not even gone to what is the test case. I have... You don't have an idea of what is to be tested. It's not my first thing. Okay. Is there a document which has got a sign from your mentor? These are the features I am going to test. Mr. Jalan sign. No. Complete this test. So you have not started it? It has expected result and... This is what I am looking for. But this is... Before even you consider this, there has got to be a specification to you of what is to be tested. Yes, sir. So people given this sheet and we discussed and personally discussed... I have to find out... This is a list of test cases. Where is the list of features? Sir, I have the document but... So did you start with the document? Yeah, we started with that document. Then we reached this document. Okay. So you had a document which says what is to be tested? The requirement sheet. We had a feature sheet. Depending based on... Correct. Now when you start with a feature list and then you come with this test plan. Okay. There has got to be on the left hand side with each test. You have to have a cross-back mechanism that this particular test is for this feature. This particular test is for this feature. Yeah. We organize in product... In technical... Product... It cannot be activity. It has to be feature. For example, if I am entering 999... Okay. Entry sheet is not like that. The feature is that on this particular entry form the quantity needs to be tested. Sir, so we modularize the cases by feature. So the order is modular. These types of features... You have not understood. If they are the form... It has got 10 fields. I should start with the list of 10 fields. These should be called field number 1, 2, 3, 4, 5, 6, 7. Then I have got a test plan which every test case I write I will say this test case is meant to test feature 1. This test case is meant to test feature 1. This is for field 2. This is for field 3. Yeah. This is not here, here. Because you are saying form. That is not correct. I don't know whether you have tested all the fields of the form. When you do a test plan there are two, three things are required. Am I testing it completely? Yeah. Complete coverage is most important. Okay. Now you went manual. So these are the prime features that we are meant to test. So based on this we had discussion. So in discussions they wrote it on the whiteboard and we made notes. We don't have a documented form of it but we didn't make notes. When I say documented this document form has to be signed. Okay. It doesn't matter. You went into manual. What did you do in manual? In manual test there are many bugs like in admin and client there is no synchronization. If admin adds a quantity and in client it is not reflected. Like this is one example. And there is one feature which is allow user to modify its placed order. Okay. So problem is that when admin changes price even he placed a previous price previous value say he can place it. You always testing it. Yeah. Correct. Because it can be done. I asked you one simple question. Yeah. I like that. I like that. I like that. When admin add the proof it won't be able to do it. Yeah. Yeah. Tested. What? I tested. First it was not reflected because synchronization is not there but I tested manually and it is It is mentioned in the Excel sheet. What I That is another Excel. We tested that feature and based on that they implemented it. So this fellow will vanish? Yeah this fellow will vanish. And suppose I have entered it, what will happen? New product will be added. When you go to the cart activity and you try to place the order it will show product does not exist. It is not real time because a technical team... When you refresh the activity and you switch from one activity to the other. Exactly when I refresh the activity is not a not. I understand sir that is why. I tested. So when you... Yes sir so when it will not... while it will not refract I will still have that in my cart the minute I check out cart the automatically the response will go to the server server will say this product is not found and it will send back the response. So while it will not automatically be removed by my cart, I will not be able to buy that product. That was your manual test? In GPS part, we have two separate applications. I implemented it just in client application. The part of admin application need to be done because I have assigned it just only client part. The GPS, since you need to sync between two apps, we started with implementing it in the client app. Now, when we see the response to the client app, we again go to the organization to ask them because this was one of the features they asked for. There are two advantages of GPS. The organization can find user according to their area. Next is that. What I learnt? I did Android Development, Testing Framework, Google API Client. You are not learning Testing Framework. You missed a very important opportunity to do proper testing. I tried to teach my group, but they don't understand anything. That's why I told them to do testing. You had an important testing assignment. Absolute learning thing. Nobody should ask anybody to do any testing unless what is to be tested is specified. First, you have to throw it like this. I won't do it. First, you have to know what to do. That is what a tester will behave. Like a coder should say design document or I won't do coding in a real flow. They ask me to write all the test cases for myself. Writing of the test cases. See, when you do any product life cycle or any software life cycle, there are set of documents. Each life cycle has got some inputs and it produces a deliverable. That deliverable along with the others actually become input for the next. For the testing phase, you need an input. The input cannot be tested application. Since the type of testing you are doing, your input has to be screen shots at least to lower level design. It should be your input because you are doing that type of testing. The type of testing which is called product test for which I require a requirement document. What you have to realize is that I can generate a product test plan even without the software having been written. Based on simple requirement document, I can have a product test plan. You have a software life cycle. The life cycle doesn't go like this. The life cycle goes like this till it reaches construction. Then it goes to unit test which is on the side. Then it goes to integration test. Then it goes to product test. Product test is equivalent to functional spec. When you draw that line, the horizontal line tells you at what stage I can begin writing my test plan. I can begin writing my integration test plan after I have got the design. Because I know how each modules interact with each other. So, I have got an integration test plan.  I can give a product test plan. I can always generate. But any test plan requires an input. And the input can be finished product test. Then I don't know whether you have covered everything. Because product is written to a specification. That is specifically because of your input. In Excel sheet, you see that first test case mention, then input is mentioned. That Excel sheet can be generated only based on an earlier document. And if I do, how will I review your test case document? Whether it is complete or not? I can only review it if I see that this document has 10 features. I have covered 10 features. Unless your test document has got a back reference to what you are testing, I cannot even review it. That is why I am saying your test document requires a back reference. Now testing is a very, very important phase of software. I have told my people, you cannot become a good programmer unless you are a good tester. And once you become a good tester, you automatically will write good programs. Because you know what testing is. Testing is the most important feature of a programmer's character. I am a very great tester. I am a great programmer also. We have an SRS. SRS is too high level for you. You are doing actually something like a unit testing or maybe at the integration level. There should be an intermediate document. You are automated test with unit test, you are other test with integration test. Your GPS testing will probably go into the product test category. What did you do? So it started with understanding the code base. So I ultimately moved on to implementing Google Analytics. So I will be demo view of the app. These are the different views I have created. The default view and the enhanced e-commerce tracking. So basically an overview of this data. Sessions is the number of times people open the app. I can set the time for a session, 5 minutes, 10 minutes, 15 minutes, whatever I want. Average session duration, by the time the user leaves the app and kills the app. This is not minimized. This happens when they kill the app. Average session duration. Bounce rate is someone opening the app and going away. Which doesn't happen currently because we have tested it ourselves. So we are not going to close the app automatically. Goal conversion rate. I will get to that later. Enhanced e-commerce. Enhanced e-commerce is one of the special libraries that Google has. So Google has an e-commerce API which they deprecated and introduced enhanced e-commerce. So these are basically, I have set this funnel. So this funnel, the downside is it has a limit on the number of hits. Which is why error analytics we are doing via Flurry analytics. So we split analytics into two parts, Google and Flurry. So we have more hits going to the dashboard. So we can analyze them. This is a funnel that has been set up. So when a user views the product, adds to cart and checks out cart. That is the ideal goal. So it will be logged whenever there is a hit accordingly. Now what is a hit? So Google analytics has, enhanced e-commerce has four basic fundamentals. So impressions, events, transactions, conversions. Impression is when I view a product. It's made an impression on me. Impressions can also be when I open a product and view related products. So that is another impression. So typically in a real life flip cart and all don't go more by impressions. They go more by related products. Because the idea is again clustering. It makes it easier to analyze their user group. And accordingly they can apply algorithm and machine learning to analyze the user set. So the entire idea of analytics is not to analyze what a user does. It's to analyze what a user group does. These are a few charts that have been made. You have an overview of the number of users. Now there have been no users because this is the time I actually started creating dummy data for this. So you can see. I did not create the user group yet because it's not real data. So creating user groups right now would lead to a lot of issues in analytics later. So there is a channel grouping option. I'll get to that. I'll get to that. But since he has not written software, we can say that it will work. We have used software. But whatever way, you have done some configuration on that. Yeah, a lot of these charts. So the idea behind Google Analytics is reports and segments. So this add segment option is basically adding either user report or screen views or demographic language session. So all that data and adding segments, creating reports. Yeah, I configured Google Analytics. And for Google Analytics to work, you also need data to go. So adding all the trackers to the various functions in the code. So when I view a product, that code should send that hit with that label to Google Analytics. So everything in the app, when I view a product, when I send a referral to another member, when I check out a product, when do I want product details? Yeah, in the code. Some tracker to it, so it sends a hit. So which is why again, we went with slurry for error reporting, because errors are something you want to look at more closely. So errors are also going to send a lot of hits. So currently we don't have many errors, but we may have errors at some point. So we segregated errors and data of the user. So these are the goals that we want the user to complete. And accordingly there is conversion for each goal. I'll get to product. So this is a product. This is the number of times it's been viewed. I haven't set revenue setting because we still haven't decided on what revenue model we want to go with. Ideally it's supposed to be a zero revenue model. So for us, what the price of the product is and what we are getting out of it won't make sense. Instead if we add, okay, this product has this much revenue for us. So that data would make more sense. So that is what we are setting up currently, a proper revenue model. But ideally this is the product hits from this screen. Now these have been segregated by screen. So from the cart activity which is the final checkout, these are the products. When I go into product detail or search results, those are other products. So you basically know which they have viewed and finally which they have selected to add to their cart. So this is cart activity. So these are the ones they have decided to add to cart and these are the number of times they have been added to cart. So there are various parameters I can segregate them based on. So one more important as I was discussing cohort analysis. So this is one of the beta functions we added. But the reason for this was this function was there before. They added a specifically a separate section because it is that important. Now cohort is basically a group of users like I was saying. So when you run. No problem. Yeah. You're going to go over it, right? Yeah. Okay. Then somebody else will add some function. As in? How do you say wrap over it? As in? Yeah. So that is what I am saying. So I have documented I am making the next week I am here. So the next week my entire task will be to modularize this code. So all they have to add is one tracking function there. That's it. And I will document that accordingly. There is already Google documentation but I will document that also. Okay. You add this when you. So there are events and there are activity trackers. So an event is when I click something. So ideally an event would be when I click I can add an event to an activity and modify the labels accordingly.  So I've segregated the code accordingly. I can show you the code. So yeah. So cohort analysis helps you analyze by segment. So suppose I want to track from June 25 for seven days. Okay. I did some activity. I introduced some coupon. I introduced some new offer. How many of my users actually stayed with me for the period of seven days? So I can add a number of days to that. I can add a different segment to that. No sir. Google tracks it. Yeah Google tracks it but depending I have to send the tracker to them. Yeah. So apart from that you are testing I did a lot of documentation and I made flow charts for various designer and developer issues. Okay. Thank you. Thank you. And personally I would like to thank Nagesh sir, Kiruzama, Mavinath sir and Sameer sir also.