We have our next pre-center, WJ, I'm just suggesting Sexton, he's a beef nutritionist, beef nutrition extensionist at MU and he's coming to you to talk about grazing wedge use in beef production systems. Please welcome Justin. Good morning. And so the title of my talk is related to grazing wedge use in beef production systems and the primary reason that it is related to beef is because that's what I do, but it certainly is applicable to multiple species of livestock and we'll talk a bit about that as we go forward. And so just I guess kind of the way to start is what is a grazing wedge? And so the grazing wedge is a concept that was kind of started in the grazing dairies specifically in the southwestern part of Missouri where we look at our forage inventory in a visual system and so the grazing wedge kind of what I would say is simply explained is that this is a visual illustration of a collection of pastures. And so I use this as an illustration and maybe it's not a great one because you might be looking say 58 pastures, this is way more than I need to kind of think about. But just stay with me and I'll show you some more applied examples here in a minute. But functionally what the grazing wedge does is we go out and we inventory our forage with something as simple as a yardstick or as complex as a sonar reader on the front of a four-wheeler. And so from a technology standpoint you can use a yardstick or a grazing stick in this case. You can use a rising plate meter either digital or manual or you can get a sonar amounted deal for the front of your four-wheeler. And Dr. Kallenbach, one of my colleagues is actually working on being able to take pictures using Google Earth to take forage inventory. And so the technology is fairly diverse I guess is the way I would say it. But the grazing wedge gives us a visual picture of our forage inventory. And so it's kind of a stoplight system in that once our pasture in this case turns red we've gotten to the point where that pasture from a quality standpoint is too mature. And if we keep our pasture in the green area then we have optimized forage quality. And then when we get it into the yellow that is the point where we have overgrazed it. And that's based off of measurements that we're taking as infrequently as once a month. Ideally what we would like to see is about every 10 to 14 days. And so a bit of background as it relates to this program is it's part of a sustainable agriculture research and education grant research and education specifically. And we have producer cooperators that collected a lot of this data and we've we've developed these producer groups that are centered around these producers that use their forage growth data as kind of indicator values throughout the grazing season. I'll show you that in a minute. And so the idea behind the grazing wedge is objective pasture management in that many people have implemented rotational grazing systems. But many times we rotate through those systems in a pattern that maybe is convenient but not best from a forage management standpoint. Do we always start with south facing slopes early in the season? Or do we start with the one that's closest to the barn? And so this allows us to look at pasture from a standpoint of growth and seasonal growth and try to best utilize it. We measure and monitor that over the over the the entire pasture season. But really what we found through this work with the with the producers is that first pass through the pasture sets it for the rest of the year. If you do a good job of pasture management in May, the rest of the year is very easy or specifically late April I should say. But once that reproductive plant portion has been taken off at the beginning, the pasture is kind of set for the rest of the year. And so if you want to think about that from an applied standpoint, what's the best pasture that you'll see all year long? It was largely cut as hay, right? Uniformly grazed in theory. And so that regrowth, we don't have any stems or reproductive tillers that we see later on in the season. So how do we set up a management system that addresses that goal at the end? The other thing is it helps us to address which forage should we use next and this I apologize doesn't show up real well with the amount of light. But one of the things to think about is if you go through and graze a system and let's say you have an eight pasture system, right? And so you've set up some sort of grazing system early in the spring, you'll go through and graze a pasture. And about mid May, it looks really good, right? It looks really good. It's been nothing but regrowth. And then you have some pasture that looks similar to this over here where you start to see reproductive or seed heads start to produce. And so you say, well, I need to go graze this because I haven't been there yet. Right? That's the next pasture to go to. And I haven't been there yet. But in reality, what I want, we've used the grazing wedge is to challenge producers to stay. This is the part of the farm that we should be making hay on because it's already too mature for the growing stock that we have in place. And this is ideal in terms of forage quality. And once forage goes bad or gets mature, goes to the red part on the grazing wedge, it's already mature. It'll take the cattle longer to get through this more mature material. And in the end, this stuff starts to get overgrown. And so from a management standpoint, that's part of the question that we try to address with the grazing wedge. And so when we started, this is Denny and Mary Beth Pokes grazing wedge that we started in 2010. And this was the 23rd of May. And this is kind of the visual image that when you when you take those forage quality measurement or those forage inventory measurements, you get a visual display of your pasture. And so these are each of their pastures that are labeled. And so what we see in a lot of beef enterprise systems is we we start to push a lot of forage ahead into the summer. Right. And so beef systems are inherently more tolerant of poorer quality forage. The biggest question that we get from beef producers is I need more forage. It's not forage quality that we run out of I need more forage this year probably more so than ever. And so the dare or the grazing wedge was actually started in the dairy system and the dairy system, they're highly aware of forage quality. And so one of the things that we set out to do was just try to see how this work with the beef production model. And one of the first things that we observed was that we see a lot of our beef producers maintain a lot more forage specifically at this 3500 pounds and of growth more so than our dairy who much like it to be under 3000 pounds more about 2750. And so to put that in a practical term, you want forage in a beef production system to be about the height of the eyeball on the cow. That's when her head's down, right when her head is down. Eyeball high is a good forage availability and quality guideline.  Okay. Good Lord put a grazing stick on every cow between the eyeball and the nose. Jim Garish is actually credited with that concept. But we're trying to put that on a visual perspective from a standpoint of how we can inventory our pastures. And so the critical points in a grazing wedge, this is the four H farms grazing wedge and in the towards the end of June this year. And what we want to do from a fertilizer and management standpoint is ideally we have a pasture that's being staged right along. Right. When we get to the point where our pastures are all flat. We have a forage shortage coming. And so this visual illustration that we we send out to these producers every two weeks or the producers submit every two weeks tells them that when they get to pasture five on a 21 day rotation, if it falls below this line, you need to start thinking about some sort of forage management system to meet the deficiency. Right. And so this year it was great to kind of look at we started it wasn't great. I'm not glad we had a drought. Okay, but it illustrated the appropriateness of this where we start to see we start to see these pasture levels turning flat. And we can start to make management decisions before hay prices get to $100 a ton. And so it helps us from an inventory management standpoint. And what we want to do is maintain forage quality here, and make sure we don't overgraze it on the other end. And so that's what we call the critical points. As we think about interpreting the grazing wedge, here's kind of how you can think about this is that when it's underneath the line, I'm setting myself up for a forage deficiency going forward. Right. If I can keep it above the line, I've got enough forage that it's right at the eyeball high of the cow. And this 1500 line, this is like thinking about how many bales a hay you have functionally, in that I can graze it down to 1500 pounds of dry matter. And everything above it is forage on the stump. And so it allows us to start calculating how much forage we have. I visited with our livestock specialist this morning. And this is something that we're going to go out and do right now. This is the ideal time to go out and measure your forage because it's not going to grow anymore. The amount of forage that you have right now is what you're going to have available. And so I can calculate how many days of forage I have out there and start to balance my supplementation needs going forward, whether that's a supplement or hay. Fundamental concept as it relates to the grazing wedge is let's graze at the 1400 pounds of dry matter per acre on the first pass. Okay, and so that is a very tight system. It is extremely tight from a from a forage height standpoint, but that sets our pasture up just like running a haybind across that field. And the regrowth is going to be vegetative for the rest of the summer. Okay, one of the things that we really struggle with is we have non uniform grazing equals non uniform regrowth. And you've observed this out in the pastures. I would assume is that around manure piles or urine spots, we see this tall forage that those cattle never come back to. And it's not because it's the manure pile per se, but late in the season, this is mature. And they've got other vegetative forage to eat the rest of the year. And so we want those cattle to be very aggressive. The first pass through when the forage is very good in the manure piles are generally fairly loose. And then we set up the season or set it up for the rest of the season. This is some of the forage quality that we've observed in these grazing wedge systems. And so I like to show this line. This is crude protein. And the crude protein requirement of the beef cows right about here. Okay, and so in terms of protein content, management under this system provides more than adequate protein to those cows. But maybe more importantly, what we looked at is what is the fiber content of that forage. And so from a from a productive standpoint, what I want you to think about is a high bar on this chart is bad. Okay, a high bar is fiber. And fiber is not highly digestible. And a low bar here is indigestibility. So best way to illustrate this is what we observed is something that we've told producers for a long time is if you want to maximize the harvest of indigestible forage make your hay in July. And the forage samples that we took under this system certify that is that the forage is not as digestible in July and August, and we produce a high amount of fiber. So focus excess forage harvest in April, May and June. And because we've used the grazing wedge, we know what our forage inventory is going forward as well as a from a growth rate standpoint. And so from a second past forage standpoint, we think about how can we best utilize the forage if I say, I want you to graze it to three inches tall, and you say that's pretty poor quality forage for lactating cow. And so what we want you to think about is well, is there some replacement heifers that could utilize that poor quality forage? Is there some dry cows that could utilize this poor quality forage to get it down to that 1400 pounds of dry matter? And so I like to show pictures of these are the groups of cattle or livestock that most people have standing around. We have some late gestation cattle. We have some early lactation cattle. We have some cattle that are ready to be weaned. And then we have a group of growing cattle or replacement heifers. And if you think about a prioritization standpoint in that how do we match our forage, grazing wedge to our cattle, is that something that is pregnant and getting ready to calf or lamb or kid, whatever it is, they have first priority of forage, they get the first bite. Okay, after that, it's the lactating animal. Because if she doesn't have adequate condition at calving, you'll never add condition to her unless you start carrying a feed bucket. And so we educated our producers such that we want these cows to get the green forage. And then if we have some red forage that we're not going to bail, these are the type of cattle that we want to use that on because they have lower nutrient requirements. So as you prioritize gestating cattle are first, early lactation cattle are second, these two groups are fairly flexible, depending on your production goals. And so that was part of our educational component was matching it to the forage supply. I like to show this in that if you bush hog pastures during the month of July, that's not a product of the month of July, it's a product of forage management in April and May. And that if if you're if you're cleaning up pastures in in May or in July, sorry, many times what has happened is that pasture got away from you in May. And if we can graze it appropriately, April and May really focus our forage management efforts using these tools, it minimizes the amount of fuel and time that we have to spend cleaning up grazing mistakes, so to speak. The other thing that this system allows us to do and I realize of one of them as a producer, no one likes keeping records. And it's like the number 20th thing that people like to do. And so by entering these yield numbers, you can actually determine we actually determine in the grazing wedge what the pasture yielded in grazeable forage. We look at it over time in terms of forage disappearance. And so this is Denny Pogue's pasture. 2012 they've harvested anywhere from two to three tons per acre off of those pastures. And that's based off of forage measurements that he's taken throughout the season every 14 to 21 days. And that allows us to see that five B and four C are maybe not as productive as 10 E. And so if I have to prioritize my fertilizer, or I'm going to apply manure or something along those lines, these are the two pastures that are perhaps most in need. Or I know that there's more water holding capacity maybe in 10 E maybe that's in the bottom. And so I'm going to put a higher level of nitrogen there because I know I get a response. And so this allows us to look at our pastures objectively and see actually which pastures green up earlier in the spring as well without keeping records just as an inventory management standpoint. Okay. And this may be a little small for those of you in the back. But at the end of the year, we also print out a summary report. And so this is he's has started taking taking measurements the 31st of March and took them all the way up to the 20th of October. And this is 2012. And this is estimated growth rate. So one of the things I like to visit with producers that we've shown from this data is we'll grow three cows worth of feed a day, the end of April and early May on one acre of ground in that the amount of feed that comes out early April and late April and early May, we can't stock for that. There's no way we can stock to consume that amount of forage in a short period of time. And so what we look at as we get down here into June and July, we're growing four pounds of feed per acre per day. And that's not a surprise. But normally we would see this in the 25 to 30 pound range, but this was 2012. And so it allows us to go back and say what was our pre grazing and post grazing cover? And what does that done to the long term growth rate or past your health? And can we maintain an average pasture cover around 2,300 pounds? And so it's a record keeping system that is a product of an inventory management. If we take those measurements, this is all generated for you. And you can look at your grazing season at the end of the year and see what kind of growth rates you received on each of these pastures. And the other thing that kind of indicates is what we call the key indicators. And this is where each of these producers who are kind of what I call our sentinel producers, they're posted on the internet. You can look and I've shown the website several times, but you can see where they're at relative to the state and what's going on. And so in this case we see that we have got beef stocker cattle on the pasture. The forage growth rates about 12 pounds an acre per day. And those stocker cattle are being fed seven and three-quarters of a pound of grain, or a pound of hay, sorry, and critical issues. They make notes and so you can kind of see what's going on throughout the state. And this one's weed control is working well, one and a quarter inches of rain yesterday, total rain since the end of April 1.75 inches. And so the producers are commenting on what they're seeing locally and allows us to kind of use those as a as a guideline to what's going out going on out in the state. And as you find it if you're interested in joining these groups it allows people to kind of say here's an indicator, may not be current for me, but it allows me to know what's going on relative to other locations. This is the one example that I think probably has the most value that we learned through working with producers is the fall inventory, in that there's nothing worse than realizing that you don't have enough hay about the middle of February. Because there's not a lot of hay being produced in the middle of February and everybody else has realized that same thing at about that time. And so from a cost standpoint as we went through the financial analysis of these operations is that how can I predict the amount of grazing days that I've got before I'm going to have to feed hay and then how much of that hay am I going to use kind of going forward. And so this is just a label of a bunch of pastures and this is the amount of dry matter that's available on the stump. And so this is the amount of forage, this is the amount of acres in each of those paddocks and then it calculates tons of feed available in each of those pastures. And so you take how many cows you've gotten, how many tons of feed, and then you can look at your hay supply and match our forage availability with our intake, hopefully. Such that you get to the point where as an inventory management tool inventory is one of the biggest challenges we face is that I don't want to spend more money than I have to because it's tied up in the hay, right, all year long until I need it again. But I certainly don't want to have to pay two times for the hay because I ran short at the worst possible time of year. And so we use this fall inventory in that as something I would have you take home today is if you're not interested in the grazing wedge at all throughout the growing season the fall inventory component is as useful as anything to plan your winter feed needs. And so our feed and forage budgeting is essentially our stocking rate which is pounds of cattle times a percent body weight intake and then the utilization rate is what percentage your forage is used. And during the growing season we're hoping that that's going to be somewhere in the 50 to 70 percent range in the dormant season it's a lot closer to 70 percent because they're going to they're going to utilize that we don't get a lot of regrowth. And then how long can I graze? You know if you if you think you've got 60 days of stockpiled forage on hand that tells you you know about when you're going to start feeding hay and and it just allows you to better manage your inventory and if you know that you have 60 days of stockpiled forage and I've shown you kind of what the quality results are under that management system we're encouraging producers to think about that stockpile as a supplement as opposed to a total diet intake. And so I explain that a bit in that people don't like buy and feed many times but what we haven't thought about stockpile is as supplemental feed I'm going to put hay out but I'm going to strip graze a certain amount of forage so that that is the supplemental feed and and I can strip graze that because one of the first things that the producers will tell me as it relates to stockpiles like Justin if I had 70 more acres to stockpile I'd have more cows and that's a that's a valid statement but what I encourage people to do from an inventory standpoint is let's think about stockpiling some forage or even just using our fall growth modes effectively by saying you know what I'm going to strip graze this off as a supplement I'm going to give you three days worth of supplemental grass and it supplements our poor quality forage so the the biggest thing I wanted you to take away with is the grazing wedge gives you an opportunity to look at how you manage your grass from an inventory standpoint what we've kind of found through our visiting with producers is they do this for about two maybe three years and after that they get a pretty visual assessment of that system and they don't go out and maybe measure as much as they would normally but they'll go out and do that one measurement in the fall and and so it's kind of a growing process to learn how the forage quality is best managed relative to yield so with that I'll take any questions yes sir you talked about mowing a pasture in in May could you hold off till June and bail it up you know where you say it gets away from you could you so so relative to forage management one of the things that we we look for is that we're all trying to capture as much sunshine as we can right our goal is to capture sunshine we have soil and we have a photosynthetic leaf and how do we capture sunshine and so one of the challenges with letting that forage grow and get further mature is it starts to shade itself right and so if you think about where does grass not grow well under trees and so when it sends up a reproductive tiller or seed head it starts to shade the lower leaves and and the dairy producers have have gone to that three leaf grazing system there's only three live leaves on a fescue plant the fourth one starts to die I will answer your question I'm just going through some background okay and and so one of the things we want to do is the sooner we can stop reproductive growth in that it shoots up one reproductive tiller okay one seed head and once that's cut off everything else is regrowth right and regrowth is our quality and so we're very aggressive at addressing that early on so that the sooner that we harvest it the sooner it can start regrowing we have more moisture and cooler temperatures if we wait until June to go in and and take that closer then what we have is we don't have a lot of water available for rapid recovery and it's hotter when you mow pasture in the spring okay if you go in and hay pasture in the spring early in the spring like within two days it's you don't have a leaf out there like that you've when you get it off there you see that leaf that sticks out it's very quick in terms of its regrowth what we're trying to avoid is the shading as much as anything and that as it gets go ahead yeah so bailages are best option or stock such that so one of the you know there's a there are a number of people that are what i call hay haters right they think hay is the bane of a pasture system and so one of the things we think about is on a fall calving system we keep those calves around to help us manage that excess inventory of forage and then we sell those calves in June and and that relieves the amount of stocking rate such that a cows can go through the summer that's one option if you can't make hay in May what i i bailage is our best option and where we can make it wet yeah you gotta have a wrapper yeah no you can not you you might try that but it won't be very successful well and and so from a yeah those are hard to try to do that as well but that's where you know maybe it's even a custom deal or manage your stocking rate stocking rate being the big one in that how do i match the forage that i have and most people you know stocking rate is the number one factor influencing the success of of a pasture system is that do you stock for 2012 stock stock for 2012 or do you stock for 2008 one of the wettest years that we've had and and the question is is it it depends and so how do i build flexibility into that system and what we found is many producers don't know how much forage they can grow under a management system this gives us the opportunity to look at that as a forage growth rate and then we can start to put an animal system on it that's well matched grazingbeefmissouri.edu


Hello everyone, welcome back. In today's video, we are going to talk about a very important experiment in physics. An experiment that played a very vital role in the development of the basic ideas of quantum mechanics almost a century ago. That is the photoelectric effect experiment. I'm going to talk about four distinct things. First, we are going to talk about the photoelectric effect experiment and its setup. Second, we are going to talk about the experimental observations associated with photoelectric effect. Third, we are going to talk about the classical explanation of those observations or the failure of the classical explanations of those observations. And we're going to talk about Albert Einstein's idea of photoelectric effect, which won him the Nobel Prize in physics later on. So what is photoelectric effect? It's a very simple phenomena. It's a phenomena in which when incident radiation or light falls onto a metal surface, electrons are emitted. Whenever light of certain suitable frequency falls on a metal surface, electrons are ejected from the surface. This phenomena is known as photoelectric effect phenomena and the electrons that get ejected from the metal surface due to the action of some incident radiation, these electrons are known as photoelectrons. Now, I want to study this kind of a phenomena because there are so many different parameters involved. We have light. Light may have properties like frequency, wavelength, intensity. We have electrons which can have properties like kinetic energy, number of photoelectrons, etc., etc. We want to find the relationships between different kinds of quantities. For that, we have an experimental setup. This is a very basic experimental setup that we have that I want to use to just understand the observations involved. So first of all, we have this evacuated tube that has two electrodes, positive and negative, that is connected to a variable voltage supply. So we have a variable voltage supply created by the combination of a battery and a rheostat, which are connected to the positive and the negative terminals inside this evacuated tube. We have a wattmeter to measure the voltage difference between the electrodes and an ammeter to measure the current flowing through the circuit. So the positive terminal is the anode, negative terminal is the cathode. If we radiate the metal plate associated with the anode with some sort of an incident monochromatic radiation, then under suitable conditions, electrons are ejected from the metal surface of the anode. And if these electrons have sufficient energy, they go and reach the cathode and that constitutes a current in the ammeter. All right. Now, this is a very basic, simple setup that we have. If you study different books that they might have a little bit of a more complicated setup with possibilities of polarities of voltage being changed, et cetera, et cetera, I have kept a very basic setup because I simply want to understand the observations in a simple manner. So essentially, whenever you have incident monochromatic radiation falling on the metal surface, these electrons get ejected. They have some kinetic energy to overcome the potential barrier because you see this is negative polarity. They overcome this polarity difference and become part of the current in the circuit. Now electrons are negatively charged particles, right? Here, however, the polarity is positive on the left hand side and negative on the right hand side. So what is the direction of electric field? It's from left to right. Negatively charged particles travel usually in the opposite direction. They're supposed to travel in the backward direction. So if there are electrons traveling from left to right, they will experience some retardation, right? They will experience some deceleration in that particular journey. Only those electrons that have sufficient kinetic energy to overcome this negative potential difference will be able to reach the cathode. So let's suppose that these electrons have a kinetic energy, Ke. Now all the electrons will not have the same kinetic energy. So let's suppose we are only interested in the maximum kinetic energy possible for these photo electrons. So as these electrons go from left to right, many of the electrons will not be able to reach the cathode. Only some of the electrons which have very high kinetic energy will be able to reach the cathode. And whether or not it reaches the cathode also has to do with the potential difference between these two terminals, right? So for example, if the potential difference between these two terminals is very low, we will have a large number of electrons reaching the cathode thereby constituting a higher current. If we slowly increase the potential difference, then slowly, slowly more and more electrons will stop somewhere in the middle and a very less number of electrons will reach the cathode thereby constituting a smaller current. So increase in the potential difference between these two electrodes will decrease the current associated with the circuit because smaller number of electrons will now be able to go from left to right. A point is going to come in which if we take the potential difference between these electrons to a certain value known as the stopping potential, then the total amount of current in the system will come out to be zero. This is the particular point in which the maximum kinetic energy of the electrons is unable to overcome the potential barrier. Now what is the potential barrier? If we give some kind of a stopping potential, let's suppose V0, then because these electrons have electronic charge of E, so E V0 will represent the total amount of work that needs to be done for the electrons to go and overcome this barrier. So the maximum kinetic energy, the moment it becomes equal to E V0 or less than E V0, then entire current in the circuit becomes zero. Therefore this extinction potential or this potential at which the current in the circuit becomes zero is known as stopping potential. Why is this stopping potential important by the way? It's important because it is a measure of the kinetic energy of the electrons. You see how else are we going to measure the kinetic energy of the electrons? We don't have a microscope that is looking at an individual electron and following its path and calculating its velocity, right? We want to know the energy of the electrons and this is just a technique to figure out the kinetic energy of the electrons. So essentially the stopping potential is a measure of the kinetic energy of the photo electrons emitted in this metal surface that is necessary to overcome the potential energy difference here. So whenever we reach this particular stopping potential, the entire current becomes zero. So below that stopping potential, the kinetic energy is basically greater than E V. So if you have some V which is less than V0, then the kinetic energy maximum will be greater than this and we will end up getting some sort of a current, right? So this is simply a mechanism to figure out the value of the kinetic energy of the photo electrons. The stopping potential is a parameter that gives us a measure of the energy of the photo electrons. Now let us discuss some of the experimental observations associated with this kind of an experimental setup. The first observation is that the photoelectric emission is an instantaneous process. Now of course this process is instantaneous up to the limits of experimental accuracy. So we can take some time frame of around 10 to the power minus 9 seconds. It means that if you look at the process of photoelectric emission, it is instantaneous. That means there is no time lag or almost no time lag between the arrival of the incident radiation and the emission of the photo electrons. So the moment incident radiation falls on the metal surface, electrons are ejected immediately if the photoelectric effect is happening in that situation. Now this is something very peculiar according to classical physics because according to classical physics, we have the wave theory of light in which light energy is spread out in a wavefront. And because light energy is spread out in a wavefront, therefore a metal surface can absorb the light energy in a continuous fashion. And because metal surfaces can absorb light energy in a continuous fashion, therefore there should be some time delay before enough amount of incident radiation energy has been absorbed by the metal surface so that the electron can now come out of the metal surface. Theoretically speaking, you can have hours, days or even weeks elapsed before the metal surface has accumulated enough energy for the photoelectron to come out. So for low intensity of radiation, some time delay has to be there before the electrons which absorb the incident radiation energy accumulate sufficient energy to come out of the metal surface. But that is not happening here. The experimental observation is that the moment incident radiation reaches the metal surface, photoelectrons are emitted instantaneously. There is no time delay and that is something that cannot be explained by classical physics. Now let's move on to observation number two. The second observation is that the kinetic energy of the electrons. The electrons have some kinetic energy right, which is related to the stopping potential as I just now mentioned. The kinetic energy of the photo electrons is independent of the intensity of the incident radiation. So let me draw a graph to show you the experimental observation. So if we measure the voltage difference between the terminals or the electrodes versus the current in the system, the graph that we end up getting looks something like this. What happens is that for zero potential energy difference, we end up getting the maximum current because that is the situation in which vast number of electrons can go from left to right. So let me say that this is a particular experiment for constant frequency. So let's say that here frequency is a constant. We are not changing frequency. It's a monochromatic radiation. So frequency is a constant. So in this situation for a given value of intensity, so let's say the intensity is small i1. So capital i corresponds to the current. Small i corresponds to the intensity of the incident radiation. So when intensity has some value, we end up getting some current. And as we increase the potential difference between the electrodes, automatically the current becomes zero because lesser and lesser electrons are able to overcome the potential energy difference between these two terminals to constitute the current. Now what happens if we increase the intensity of the incident radiation? The moment we increase the intensity of the incident radiation, so let's suppose I make it to i1 or rather I should say this should be small i and I make it to small i, then what happens is that immediately the current in the circuit increases. Now what is current? Current is essentially number of electrons passing through the ammeter per unit time. So greater current simply means greater number of photoelectrons that has reached the cathode. The moment we increase the intensity of the incident radiation, the current in the circuit has increased but it also corresponds to the same stopping potential. Stopping potential corresponds to the maximum kinetic energy of the electron. So even though I have increased the intensity of radiation and it has increased the number of photoelectrons, the individual energy of the photoelectrons is still the same as for the lower intensity. So I can keep on increasing the intensity. If I make it 3i, so for an intensity of 3i the current will again increase but the stopping potential corresponding to that is exactly the same as before. That means increasing the intensity of the incident radiation will increase the number of photoelectrons but not the individual energy of the photoelectrons. Now this is something that is very difficult to explain using classical theory because again what do we mean by intensity of the incident radiation? Intensity corresponds to energy of the incident radiation. So when we talk about energy of a wave, we are essentially talking about its amplitude. So if the amplitude of a wave is large, it has a greater amount of energy. So intensity of an incident radiation corresponds to a more energetic incident radiation. So if there is a more energetic incident radiation, then automatically it should correspond to greater energy of the photoelectrons, right? Greater energy of the incident radiation should correlate to greater energy of the photoelectrons but that is not what's happening here. What's happening here is that greater intensity corresponds to large number of photoelectrons but the individual energy of the photoelectrons remains exactly the same. So therefore classical physics fails to explain observation number two. Now let's move ahead to observation number three. So in the third observation which is probably the most important observation here is that below a certain cutoff frequency, below a certain threshold frequency, the phenomena of photoelectric effect does not happen. So if frequency of incident radiation is less than some cutoff, then we do not get photoelectric effect. Only when the incident radiation has a frequency greater than some cutoff or threshold frequency, only then we see photoelectric effect. This cutoff is known as threshold frequency and beyond this frequency, if we keep on increasing the frequency, then that simply leads to more energetic photoelectrons. That means the kinetic energy of the photoelectrons which can be measured by the stopping potential has a direct linear proportionality with frequency. Greater the frequency of the incident radiation, greater is a kinetic energy of the photoelectrons. That means blue light would lead to faster photoelectrons compared to red light. Now let me draw a couple of more graphs to illustrate this particular point. All right, so here I have two graphs. First I have the current versus the voltage between the electrodes and I have three distinct frequencies of incident radiation. So as you can see, you get a similar kind of a variation for any given frequency because the moment you have a particular light, you increase the potential difference between the electrodes, the current decreases, goes to zero at the stopping potential. The moment I compare the graphs for three distinct frequencies, I end up getting three distinct stopping potentials. That means these three distinct frequencies correspond to photoelectrons that have three distinct kinetic energies. So for every single frequency, we end up getting a different kinetic energy of a photoelectron. Now because intensity is a constant, therefore current initially is a constant, that means the number of photoelectrons in all the three cases of constant intensity of incident radiation is constant. That means for a given intensity, we can change the frequency, the number of photoelectrons will remain the same but the kinetic energy associated with the photoelectrons will be different and increasing frequency corresponds to increasing kinetic energy or increasing stopping potential for those radiations. Now we can also compare the stopping potential with frequency. So as you can see below a particular cutoff or below a particular threshold frequency which I am going to call as a nu naught. So below nu naught there is no photoelectric phenomena but beyond nu naught you end up getting photoelectric phenomena also and the stopping potential also increases linearly. Now what is stopping potential? It is a measure of the kinetic energy of the photoelectron. So that means the kinetic energy of the photoelectrons increases linearly with the frequency of incident radiation. Now this is something that is completely different from what we would expect in classical physics. In classical physics, the kinetic energy of the photoelectrons should come from the energy of the incident radiation and the energy of the incident radiation has to do with intensity of the incident radiation. It has nothing to do with frequency. In classical wave theory, the frequency does not correspond to energy of a wave. It is the amplitude that corresponds to energy of a wave. The amplitude square gives us an idea about the energy of a wave. So how is it possible that frequency variation can lead to change in the energy of the photoelectrons themselves? That is something that classical physics fails to explain. So we can see that there are three very simple observations related to the photoelectric phenomena that classical wave theory is unable to explain based on its idea of light being a wave front which is continuously being absorbed by a metal surface and the energy transfer happens in a continuous fashion and the energy transfer is related to the intensity of the radiation. All these things do not explain the three phenomena or three observations associated with photoelectric phenomena. So now we come to the last portion of the video which is the Einstein's resolution to this particular problem. So what did Einstein say about all these three different points? You see before Einstein, we had Max Planck who gave an explanation to the black body radiation spectrum. I have made a couple of lecture videos on that particular topic. So if you are interested in that topic, you can go through those particular lectures. But what essentially Max Planck said about the black body radiation spectrum is what Einstein borrowed for this particular photoelectric effect and let me just give you a very simple sort of explanation of that assumption. So if you have a black body surface, so let's suppose that you have a black body surface. The black body surface in a cavity is capable of emitting electromagnetic waves or electromagnetic oscillations of different frequencies. Now what Max Planck said was that the emission of energy in the form of these standing waves or these electromagnetic waves happens not in a continuous fashion, but in a discrete manner. That means the energy radiated by the black body walls happens in discrete values of 0, h nu, 2h nu and on and on and on and h nu. Where h is the Planck's constant, nu is the frequency. This is a very unique resolution to the problem of the black body radiation spectrum because Max Planck merely tried to change or modify the calculations so as to fit the experimental data. And the way to avoid the ultraviolet catastrophe in black body radiation was to assume that the manner in which the walls are emitting energy in the form of radiation is happening not in a continuous fashion, but in discrete values of 0, h nu, 2h nu and h nu etc. Now Max Planck did this in an act of desperation to explain the black body radiation spectrum and he did not really think much into what it means in terms of the physical reality of what light is. It is Albert Einstein who realized that this had greater implications in terms of our understanding of what light is. You see before Max Planck, before Albert Einstein, we had the classical theory of radiation in which light is composed of wave fronts, waves, electromagnetic oscillations traveling through space. But Einstein said that this brilliant hypothesis by Max Planck is not something that is unique to the phenomena of black body radiation only, but is true about the nature of light itself. That means light propagates through space in discrete amounts of energy that we call as photons or packets of energy or quantized values of energy. So this picture of radiation in which I have drawn these waves is not the picture that is required to explain this phenomena. In fact, we have to get rid of this picture completely. So if I completely forget this picture of what light is supposed to be and look into Einstein's explanation, then what Einstein simply said was that this idea that light energy consists in discrete values can be taken forward, not just for emission or absorption, but in general to how light behaves or propagates in terms of packets of energy. So if we assume that these packets of energy are these localized packets, so let's suppose every light consists of these small packets of concentrated energy which is localized in a small volume in space and every single packet corresponds to an energy given by the Planck's postulate. What was the Planck's postulate? So let me write Einstein's quantum mechanical explanation. I should say quantum explanation because till that point in time quantum mechanics did not really emerge as a subject. So I should say quantum theory or whatever. Einstein used the explanation of Planck's postulate which said that light is consisting of these packets of energy, these localized packets of discrete energy, these quantized values of energy, these photons. So we call these packets of energy as photons and every single photon has an energy of h nu. So h nu is essentially equal to the energy of one packet of energy or one photon. So the incident radiation consists of all these photons which come and reach the metal surface and the moment they reach the metal surface they end up creating photoelectric phenomena. How does that explain these observations? First of all because the incident radiation is now consisting of these packets of energy or photons and individual photon interacts with an individual electron and because this energy is not spread out it is absorbed one at a time therefore there should not be any time delay in the process of photoelectric emission. You see in classical theory because wave is supposed to be a continuous spreading of wavefront and the energy is absorbed continuously there should be time delay but now the light is consisting of these small granular particles or photons and every single photon interacts with an electron. So the moment the photon which interacts with an electron if the photon has sufficient energy for the electron to come out the electron absorbs that energy and comes out of the surface. So therefore this process is an instantaneous process and therefore explains the first experimental observation. Second the intensity of radiation has nothing to do with the energy of the photon because the energy of the photon has to do with the frequency and because we are using monochromatic radiation therefore the radiation consists of a large number of photons and every single photon contains this much energy. If this energy is sufficient for the electron to come out of the metal surface the moment the electron absorbs the photon it comes out of the metal surface. So the kinetic energy therefore is constant it is independent of the incident radiation. So what happens when we have a higher intensity of incident radiation? Higher intensity of incident radiation simply means a larger number of photons. You see so if we have a greater intensity of incident radiation that simply corresponds to a large number of these photons. So the intensity of the incident radiation is n times h nu, h nu is the energy of one photon and is the number of photons constituted in that particular incident radiation and because the number of photons is larger for greater intensity of incident radiation therefore the number of photo electrons also increases which corresponds to greater current. You see higher the intensity of the incident radiation greater is the overall energy but not of individual energy of a photon but instead you have larger number of photons and larger number of photons corresponds to larger number of photo electrons constituting a larger current. You see how simple that explanation now becomes. Let us move on to the next observation. The next observation is that for frequency below a threshold you do not see photoelectric effect which is kind of obvious because the interaction between the electron and the photon happens one on one basis. So if a photon has energy h nu if it is sufficient to cause photoelectric emission then it will happen but if the frequency is less that means the energy of the photon is not sufficient so photoelectric effect does not happen at all because individual photons do not have sufficient energy for the electrons to come out but now if we increase the frequency then the individual photons will have greater energy so the electron can absorb that energy and come out of the metal surface and it happens in a linear fashion why because if you look at the phenomena of conservation of energy then the photon energy one photon which interacts with the electron essentially goes into what? It goes into the electron for the electron to overcome the metal surface threshold because the electrons are part of the metal surface they cannot just come out randomly there is some amount of energy it requires for the electron to come out of the surface right otherwise we would see electrons pouring out of metal surface all the time no so it requires some amount of energy to come out of the metal surface first so that is known as work function or some sort of a threshold function so first of all it needs to overcome the work function of the metal surface and if there is an excess amount of energy beyond the work function that goes into the kinetic energy of the electron so that goes into the kinetic energy of electron so this translates into a very beautiful equation the photon energy for every single photoelectric effect interaction between a photon and electron is equal to h nu contributes to overcoming the work function of the metal surface and the rest goes into the kinetic energy of the electron so this gives us a very simple equation of k e max is equal to h nu minus w which is the Einstein's photoelectric effect equation now we can go a step further what if the amount of the photon energy is exactly equal to the metals work function if the amount of let's suppose the work function is exactly equal to the let's suppose photon energy that corresponds to the threshold frequency right when we reach the threshold frequency then the photon has just enough energy for the electron to be ejected but it doesn't really have much kinetic energy all right so all the energy gets absorbed in just the electron coming out of the metal surface so that corresponds to threshold frequency right so if I put k e max is equal to zero h nu is equal to w but that nu corresponds to threshold frequency so if I substitute h nu naught into w here this simply gives me a new equation which is what k e max is equal to h nu minus h nu naught this is the very famous photoelectric effect equation given by Albert Einstein and this explains this particular graph that the moment we increase the frequency there is a linear relationship with kinetic energy of the electron in fact I can substitute e v naught here in kinetic energy max and I get a little bit of a different result so if I substitute e v naught I should get v naught is equal to h upon e nu minus h upon e nu naught you see this h upon e comes from left hand side h upon e nu naught so what is this equation this is the straight line relationship here v naught versus nu so if we trace this line below it will create a negative intercept which is equal to minus h upon e nu naught and because h upon e is a constant v has a direct proportionality with frequency the slope of this line will give you an idea about h upon e so if you know the electronic charge if you perform this experiment in some sort of a lab then by the slope of this line you can measure h upon e and finally you can measure the value of the plan constant in fact this is a very popular experiment in laboratories in some colleges where you can use the photoelectric effect phenomena to draw this graph and by applying the electronic charge value you can calculate the plan's constant from here so you see how Einstein was successfully able to explain these three phenomena and provide a very simple very simple equation which is known as the Einstein's photoelectric effect equation to explain the photoelectric effect experiment or phenomena but it happened at a cost and the cost was to completely get rid of the previous wave theory of light you see when Einstein wrote this paper in 1905 many scientists did not like this paper because it went completely against the previously held belief of what light is light was supposed to be a wave a wave front which transfers energy in a continuous fashion with matter that is what we know from classical electrodynamic theory. Einstein proposed that light was instead composed of packets of photons having some energy and interacting individually with an electron just like one particle electrons a particle interacts with another electron so even though the simple equation explains these three phenomena or these three observations it happens at the cost of a radical shift in how we look at what light is in classical theory light is a wave front a wave in this new theory that we are developing right now in front of our own light consists of these packets these localized photons having energy that is directly proportional to its frequency that interacts with particles like electrons just like another particle interacts with a particle and because of this genius of Albert Einstein he actually got the noble prize in physics for this particular experiment you see Einstein did not get the noble prize for relativity or GTR he got the noble prize for photoelectric effect that is how significant photoelectric effect is in the development of these ideas so I hope you have understood what photoelectric effect is and I have been able to explain to you the classical explanations the quantum ideas behind this particular phenomena and we will take these ideas forward in our next video where we discuss discuss another very important phenomena known as the Compton effect till then I am Divya Jyothidas that is all for today thank you very much have a nice day


Extract the sealer from the noise and this is an incredible open-stack summit I'm joining with my co-host Jeff Frick and Alessandro Pugilotti. Nice to meet you. Nice to have you in the queue. I know you're running quickly. I know we're a little bit behind. Had just scheduled in about five minutes earlier but you were on stage, downstairs in the main hall. I mean, there's a packed house down there. The room's packed. It's locked down. It's hard to get out of there. It's like rushing through the crowd, stampede. But quickly tell us. So tell us about your company and give a quick overview of what you guys are doing and then we'll jump into some questions. We are doing the integration between OpenStack and Hyper-V and in general Microsoft Technologies. So we developed all the Nova Compute Driver, Quantum, Cinder, Nova Volume for some Hyper-V, Windows Storage Server. We developed also the Cloudy Need for Windows. So let's say we are focused on the integration within the interoperability between Windows and Microsoft products and OpenStack. So it's cloud-based software? Yeah, exactly. And not infrastructure? Not infrastructure. So software and services? Services, yeah. So all our products are open source, okay. And on top of it, we provide services and consulting. Got it, so it's free software. Yeah, exactly. Okay, cool. Open source, I mean, it's the model of many. We love open source, scale out, scale out open source. It's changing the world and this is really the beginning of it. Take us through some of your engagements with customers. What are you guys delivering for the kinds of services that you work with them on? Yeah, so we have a lot of customers which want to run virtual workloads which are Microsoft-based. And of course, the only real way to do that is to run it on top of Hyper-V because Hyper-V is a Microsoft product. So Windows runs in the best possible way on top of Hyper-V from these perspectives. So they are very interested about it and they come to us because they need consulting about how to do it, consulting about how to better leverage the technology, how to do massive deployments because of course OpenStack is a technology which it's mostly an employee-less scenario which are involved in thousands of servers. So not something that you can do lightly without having experience about how to do it. And we are the guys who wrote this, so we know how to do that. Yeah, that's great. And so our most engagements around where the legacy environment is a Microsoft environment, so that's where you guys are playing. So we haven't heard much about Microsoft here, John, in the last day or so. So what is kind of the Microsoft take on the OpenStack and what it represents? I'm not from Microsoft, so I cannot give their place on this perspective. That's why we asked you. You're on the ground. You're with the truth. We're going to get the truth out of the field. That's why we're in Portland, not Seattle. Let's put it this way. Let's put it this way. We are doing this work. I'm a completely autonomous company, okay? Right, right. And we work of course together with Microsoft. I mean, they're very supportive in helping us with all the information that we need. I'm a Microsoft MVP, so I work together with all Microsoft technologies since ages, okay? And of course, Microsoft has also their other technologies which are Azure or System Center, okay? So we want to make sure that OpenStack is not going in, let's say, competition with their technologies. It's actually taking a completely other segment of the market. Right, right. Well, it fits right in with everything we've been talking about, which is that people have incumbent systems. They have legacy systems. They have big pieces of investment and business running on- Yeah, I will not use necessarily the word legacy here because there are a lot of new deployments based on Windows Server 2012. For example, we are distributing now Windows Server 2012 evaluation version already packaged with all the OpenStack related features, including our Cloudyneed, all the drivers, for example, Virtayo for KVM or XenServer tools or everything related to Hyper-V. You can just download it and deploy it in Glance or in OpenStack without needing to know anything about how to do all the dirty work behind. Great. And what were you showing just now? What was your demo? Yeah, that's one of the things. I was demoing about all the Hyper-V integration. I was showing about these great news. Actually, we published it today. So Microsoft gave us this opportunity. So you can just go on our website and download these images. You have, of course, to accept the license, which is for Microsoft. It's not our license. It's completely free again. We provide it as a free service. An evaluation, of course, copy. So you can just use it in production, that's for sure. So, tag us through. I know we've got a couple minutes left here if our next guest comes up. But I want to get your opinion of what's happening here at OpenStack. Obviously it's a great community. It's grown in just credibility and authority around. You have real coders coming in, contributing software. It's open source base, good governance, real deployments, good proof of concept. So you have a lot of production action going on. So as we say, there's a lot of meat on the bone here. Share with the folks out there your observations. What's happening at OpenStack? What are the cool things that you think that they should know about?  I mean, if you think about that, it started only in 2010 and they have a very aggressive release cycle. I mean, every six months there is a new release and the quality is amazing. And also I've worked quite a lot in open source. I've worked with Microsoft Technologies and the way in which also all the code infrastructure is made, it's incredible. I mean, you can just take any nightly build to say so of OpenStack and it will work almost seamlessly. Okay, so we are of course pretty far away still from continuous deployment but the quality of the code is amazing. The quality of the contributors, if amazing. The level of coding is an enormous entry level, okay? For companies. I mean, also the way in which the core developers are evaluating and reviewing your code is very, very strict. They are rising the bar continuously. I believe that there is one of the top notch products and projects right now out there. Yeah. Is it the passion? Is it because where we are and kind of the life cycle of an open source project that we're, you know, this is one of the latter ones or why? I think that of course the history of open source project is pretty long. So when they started this project, they knew all the mistakes in the previous ones, okay? So they knew how to manage a large project like this one, consider that we had almost 500 developers here this time, which is huge if you think about this and also a lot of companies involved and this project is not controlled by anybody, in fact, because it's a... It's a community. It's a community here. So it's great from this perspective. I mean, other open source project in a way or the other are controlled by a single company. It's definitely not the case here. The vendor neutral is a great idea. Yeah, and every vendor can just take it. Another important thing is Apache 2 license, meaning that anybody can take the code and create a commercial product on top of it. So it's not like the GPI code in which you have to recommit everything back to the community. Talk about Amazon, what have they have done? Because they are the gold standard. They're doing a lot of things. They're introducing more products. Talk about the bar being raised. A lot of developers love working with AWS. It's just so good. I mean, they're doing great. But for large companies, it's not that easy. What's your take on Amazon? Well, we have, for example, a migration product which makes it absolutely easy to migrate for AV AWS. So easy to migrate to, for example, Azure, to OpenStack, or to whatever other technology. Because, of course, Amazon started this business, to say so, okay? So kudos for them to the way in which they created it. And of course, they started with already a high level, okay? So in the moment in which OpenStack started, you can see, of course, a lot of influence from Amazon inside of OpenStack. But now OpenStack is taking its own way, its own take. So now, for my opinion, it's also Amazon time to, for a confrontation with what this great project is bringing. Yeah, Amazon's got to up their game and recognize that the fight for the enterprise is going to be well defended. It's going to be tough. And also, Amazon is, of course, not the only one in the domain. There is also Azure, Microsoft. There is, of course, Google and big companies which are based, of course, on OpenStack. I mean, so it's a very interesting arena, from my perspective. And consider also the fact that, so we are originally from Europe, and a lot of companies in Europe prefer to have their data stored in data centers in their home countries, especially government-related companies. So they want to want their data in databases, in data centers, sorry, which are in Seattle, let's say, outside of their territories. Even if we live in a globalized environment. And OpenStack, it's great from an international perspective. Not only from a US perspective, it's, of course, it's the place of work of this technology. So in that use case, the European example you mentioned, it really highlights what we were just talking about, Jeff, around infrastructure as code. People, developers need to be involved in this, not just stack in a rack and see a later manage it. A lot of active, a lot of management, automation going on, which Sean from Service Mesh was talking about. We're here with Alessandro Pilat from Cloudbase. Startup, you guys are doing great stuff. Final word to you is I want you to share with the folks your goals for the next year as a company growing up in this great market. What's your goals for next year? Well, we are going up at a crazily fast rate. So we started last year, our work with OpenStack started with Folsom. We work like crazy this six months. And we released an amazingly number of new features. And we decided to rise the bar even higher for Havana. And we have even bigger plans for the next time. I mean, so take a look at our website, come to our sessions and everything because you will see great new stuff there. Great. Cloudbase, hot startup, obviously OpenStack, obviously on an inflection point, crossing over to the mainstream developers, enterprise with the big companies here. And you get the startups like Cloudbase. So this is it, this is the action here live, exclusively on siliconangle.com. Our continuous coverage of the OpenStack Summit here in Portland. I'm John Furrier with Jeff Frick. We'll be right back with our next guest after the short break.


A peace process divides in two, peacemaking and peace-building. Peace-making is difficult, but peace-building is even more difficult. Over the past half century, Latin America suffered some of the world's most brutal armed conflicts and persistently high rates of violence. Nowhere has that been more pronounced than in Colombia, where nearly seven decades of ongoing armed conflict have left over nine million registered victims, including more than seven million internally displaced persons, and at least 230,000 deaths. The United States Institute of Peace's roots in Colombia run deep, thanks in large part to Virginia Jeanie Bouvier, who led the Institute's efforts in Colombia from 2003 until her passing in 2017. Jeanie not only supported local peace builders in some of Colombia's most conflict-affected territories, but she also provided technical support to national leaders and international advisors, and broadened civil society participation during the negotiations with the country's largest insurgency, the Revolutionary Armed Forces of Colombia, or FARC, which ultimately culminated in a ground-break in Pisa Court in November 2016. The agreement was a monumental achievement for the Colombian people and brought hope to the country. But more than five years later, the accord has proved insufficient as only one part of the web of ongoing conflict with other armed groups. Insurgents of the National Liberation Army, or ELN, paramilitary successor groups and growing FARC dissident factions still compete for control over communities and territory in a quarter of the country. Today, there are rising levels of violence, humanitarian crises, political polarization, and social intolerance. In 2021, USIP opened its first regional office in the heart of the capital city of Bogota. USIP now supports a broad range of peacebuilding initiatives in Colombia to advance reconciliation and to support negotiations seeking comprehensive solutions to the armed conflict. Our program facilitates dialogues in conflict-affected communities and provides advice to police, military, and civilian leaders on how to transform paradigms in security and justice for Colombia's diverse citizens. The Institute also has contributed to a final report of the Truth Commission and trained victims and ex-combatants in restorative approaches for the transitional justice tribunal. In 2019, USIP expanded its work to Venezuela, where a complex political crisis has led to depolarization and the flight of more than 20% of its citizens. There, the Institute empowers local women peacebuilders, backs public education campaigns for tolerance and pluralism, and strengthens independent civil society coalitions seeking to constructively rebuild its democratic institutions. USIP also helps bridge groups between Colombia and Venezuela to tackle humanitarian, public health, and security challenges, plaguing their nearly 1,400-mile border controlled by armed groups. Since the violent political crisis in 2019 in fellow Andean nation of Bolivia, the Institute has supported research and political dialogues as well as organized training and grants for youth peacebuilders and social activists seeking to overcome paralyzing polarization and ingrained geographic and racial animosities. In El Salvador, Honduras, and Guatemala, USIP facilitates dialogues, promotes the rule of law through local initiatives, and empowers youth to forge peaceful solutions to community challenges. In Nicaragua, the Institute trains young democracy leaders and consolidates insights from past dialogues in the hopes that future opportunities for political negotiations will eventually emerge. In Haiti, the Institute backs initiatives to forge successful national dialogue efforts seeking to overcome endemic governance crises. For all its challenges, Latin Americans have never stopped dreaming of a better and more peaceful future. At USIP, we will do our part to help with that aspiration. I can say with no doubt whatsoever that there's nothing more exciting and that brings more peace of mind than fighting for peace.


There are three lines that make up the Bollinger Bands. The middle line is usually the 20-day simple moving average, the 20SMA. Below the middle line, there is a lower Bollinger Band, which is the 20SMA minus two standard deviations of the last 20 daily closing prices. Above the middle band, there is the upper Bollinger Band, which is the 20SMA plus two standard deviations. Bollinger Bands can also be drawn based on the weekly data, hourly data, etc. The probability of the closing price of a stock falling outside of the upper or lower Bollinger Band is usually only 5-10%. Many traders will get ready to sell a stock when the price is above the upper Bollinger Band. Conversely, when the price is below the lower Bollinger Band, there is a high probability that it will rebound soon. Of course, stock prices are also affected by fundamental issues such as company performances and macroeconomic events.