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Heisenberg鈥檚 Uncertainty Principle .txt | Now, these two experiments led directly to the following result the Uncertainty Principle, or the Heisenberg Uncertainty Principle, named after the guy who came up with the principle, Heisenberg. |
Heisenberg鈥檚 Uncertainty Principle .txt | Now, what this principle showed was that it showed that as you move downward in size from something large to the subatomic level the less your objects act like particles and the more they act as a wave. |
Heisenberg鈥檚 Uncertainty Principle .txt | In other words, if you get down to the subatomic level to the electrons and protons and neutrons the less your objects act as solid spheres and the more your objects act as waves. |
Heisenberg鈥檚 Uncertainty Principle .txt | Now, to demonstrate what this uncertainty principle states, I'll use the following example. |
Heisenberg鈥檚 Uncertainty Principle .txt | Suppose I have this relatively large ball which, from where you're sitting you can probably tell where the ball is and you can tell if the ball isn't moving so you could tell its velocity. |
Heisenberg鈥檚 Uncertainty Principle .txt | Now, suppose I go smaller. |
Heisenberg鈥檚 Uncertainty Principle .txt | Suppose I hold up this ball. |
Heisenberg鈥檚 Uncertainty Principle .txt | Now, once again, this is a relatively large ball. |
Heisenberg鈥檚 Uncertainty Principle .txt | And from where you're sitting, you could probably tell that the ball isn't moving and you could tell where the ball is. |
Heisenberg鈥檚 Uncertainty Principle .txt | Now, suppose I go even smaller. |
Heisenberg鈥檚 Uncertainty Principle .txt | Suppose I go down to this really tiny marble which you probably can't see from where you're sitting. |
Heisenberg鈥檚 Uncertainty Principle .txt | But I'll move it closer. |
Heisenberg鈥檚 Uncertainty Principle .txt | There's my particle. |
Heisenberg鈥檚 Uncertainty Principle .txt | There's my solid sphere. |
Heisenberg鈥檚 Uncertainty Principle .txt | Now, now that you saw the sphere, you could probably see that. |
Heisenberg鈥檚 Uncertainty Principle .txt | You could probably see it from where you're sitting. |
Heisenberg鈥檚 Uncertainty Principle .txt | But suppose now, I walk a mile away or a kilometer away and suppose I hold this ball. |
Heisenberg鈥檚 Uncertainty Principle .txt | Now, now, this ball becomes a spec. |
Heisenberg鈥檚 Uncertainty Principle .txt | You could still see it, but it's much, much smaller. |
Heisenberg鈥檚 Uncertainty Principle .txt | Now, suppose I walk a mile away and I hold this ball up. |
Heisenberg鈥檚 Uncertainty Principle .txt | Now, this ball you probably won't see really. |
Heisenberg鈥檚 Uncertainty Principle .txt | Well, you might see it if you have really good vision. |
Heisenberg鈥檚 Uncertainty Principle .txt | But I don't think I'll see it a mile away. |
Heisenberg鈥檚 Uncertainty Principle .txt | Now, suppose I hold this really tiny marble, the solid sphere, from a mile away you definitely won't see this one. |
Heisenberg鈥檚 Uncertainty Principle .txt | So in other words, the smaller you go, the less you see its position and the less you see its velocity. |
Heisenberg鈥檚 Uncertainty Principle .txt | If I walk 5 miles away and I hold either of these balls, you won't see any ball and you won't be able to tell where the ball is and with what speed or with what velocity it's moving. |
Heisenberg鈥檚 Uncertainty Principle .txt | The point is, and what this uncertainty principles show, is that as you shrink down to the atom and then to the sub atom, to the electron, you no longer are dealing with solid spheres. |
Heisenberg鈥檚 Uncertainty Principle .txt | They're no longer solid spheres, and they act more as waves. |
Heisenberg鈥檚 Uncertainty Principle .txt | In other words, they have both wavelike properties and solid properties. |
Heisenberg鈥檚 Uncertainty Principle .txt | And that means, because elementary particles are no longer solid spheres, there is no way to know its position and at the same time, its velocity with complete certainty. |
Heisenberg鈥檚 Uncertainty Principle .txt | So the formula or the equation for this uncertainty principle is the following plaques constant a very, very small number divided by two is always less than our change in x or the uncertainty of our position. |
Heisenberg鈥檚 Uncertainty Principle .txt | Change in position times mass times change in velocity. |
Heisenberg鈥檚 Uncertainty Principle .txt | Now remember, mass times velocity is momentum. |
Heisenberg鈥檚 Uncertainty Principle .txt | So this guy is change in momentum. |
Heisenberg鈥檚 Uncertainty Principle .txt | In other words, this is the uncertainty of our position and this is the uncertainty of our momentum or velocity. |
Heisenberg鈥檚 Uncertainty Principle .txt | And what this equation basically says is the following the less our change in axis, if this guy is very small, that means we know more information about our position, where our electron is located. |
Heisenberg鈥檚 Uncertainty Principle .txt | And that means if this guy decreases and this is a constant, this guy must increase, the smaller our change in excess, the more we know about our position, the greater our change in b is, the less we know about our velocity. |
Heisenberg鈥檚 Uncertainty Principle .txt | And likewise, the same holds the more we know about our velocity change in velocity. |
Heisenberg鈥檚 Uncertainty Principle .txt | The less our change in velocity is. |
Heisenberg鈥檚 Uncertainty Principle .txt | And the less we know about our change in x, the less we know about our position. |
Heisenberg鈥檚 Uncertainty Principle .txt | In other words, we can't be very certain about our position and at the same time about our velocity. |
Heisenberg鈥檚 Uncertainty Principle .txt | That's what the uncertainty principle tells us. |
Heisenberg鈥檚 Uncertainty Principle .txt | And this has to do with the duality nature of subatomic particles, electrons and protons, as well as a duality of light. |
Heisenberg鈥檚 Uncertainty Principle .txt | In other words, when you go from a large ball from this ball to a subatomic particle, our particle loses its solid sphere like properties. |
Heisenberg鈥檚 Uncertainty Principle .txt | It stops acting like a solid sphere and starts acting more like a wave. |
Heisenberg鈥檚 Uncertainty Principle .txt | And therefore, we can no longer pinpoint exactly where our object is and at the same time, what its velocity is, what its momentum. |
Heisenberg鈥檚 Uncertainty Principle .txt | The last thing I want to mention is the following this principle has nothing to do with how inaccurate or how accurate our instrument is, or how inaccurate or accurate our methods or experimental methods are. |
Heisenberg鈥檚 Uncertainty Principle .txt | In other words, even if we have the perfect instrument and our methods were the perfect methods, we still would not be able to pinpoint exactly where our object is, our electron is, and exactly with what velocity and in which direction our electron is traveling. |
Heisenberg鈥檚 Uncertainty Principle .txt | This principle has nothing to do with our instruments. |
Heisenberg鈥檚 Uncertainty Principle .txt | It is completely a byproduct of the nature of electrons, of the fact that electrons move as part particles and at the same time, they move as waves. |
Fuel Cells .txt | In this lecture, we're going to look at something called fuel cells. |
Fuel Cells .txt | Now, fuel cells are electrochemical cells that produce electrical work from oxidation of hydrogen. |
Fuel Cells .txt | Now, fuel cells are very commonly used on spacecraft. |
Fuel Cells .txt | They provide electricity to the various supply and system spacecrafts. |
Fuel Cells .txt | So let's look at oxidation and reduction oxygen reactions found in a fuel cell. |
Fuel Cells .txt | So our oxidation is as follows. |
Fuel Cells .txt | A diatomic hydrogen is oxidized and it releases two H plus ions and two electrons. |
Fuel Cells .txt | Our reduction reaction is as follows. |
Fuel Cells .txt | A diatomic oxygen molecule takes up those two electrons and also takes up the two H plus ions forming water in a liquid state. |
Fuel Cells .txt | Now, our neck reduction reaction is found by simply adding up these guys. |
Fuel Cells .txt | We see that the H two plus ions cancel, the electrons cancel, and we have the following redox reaction. |
Fuel Cells .txt | Now, our e is 0.7. |
Fuel Cells .txt | Our cell potential for our fuel cell is zero 7 volts. |
Fuel Cells .txt | It's positive. |
Fuel Cells .txt | Now let's look at the layout of a fuel cell. |
Fuel Cells .txt | A fuel cell, like any other electrochemical cell, has an anode and a cathode. |
Fuel Cells .txt | It has a conductor that carries electrons from the anode to the cathode. |
Fuel Cells .txt | And this is our outside system that receives electricity in the form of moving electrons. |
Fuel Cells .txt | Now, like always, like most cases, our anode is negatively charged and out cathode is positively charged. |
Fuel Cells .txt | And that's why electrons travel from the negative charge to the positive charge. |
Fuel Cells .txt | Now, inside our anode, we need to allow H two molecules in the gas state in. |
Fuel Cells .txt | And that's why we have an outside power source that allows those H two irons or H two molecules inside our anode. |
Fuel Cells .txt | And to make sure our pressure is not increasing, make sure there's no build up in pressure, this needs to be released back into some outside location. |
Fuel Cells .txt | That's why we have this guy on the bottom. |
Fuel Cells .txt | So when this H two molecule enters our system, it is oxidized. |
Fuel Cells .txt | But how is it oxidized? |
Fuel Cells .txt | Well, this brown layer is a platinum catalyst. |
Fuel Cells .txt | And this platinum acts to catalyze or speed up that reaction going from our reacting to products. |
Fuel Cells .txt | So when this guy in a our anode, it reacts with the platinum catalyst producing two moles of H plus ions and two moles of electrons. |
Fuel Cells .txt | Now, these two moles of electrons travel via the conductor this way. |
Fuel Cells .txt | Notice we have a membrane. |
Fuel Cells .txt | And this membrane does not allow our electrons to pass from this anode to capital via this membrane. |
Fuel Cells .txt | This membrane only allows H plus ions to flow or protons to flow. |
Fuel Cells .txt | Now, why should we allow protons to flow? |
Fuel Cells .txt | Well, we'll talk about that in a bit. |
Fuel Cells .txt | But notice some of the H or diatomic H must leave because we can't have a pressure build up in this system. |
Fuel Cells .txt | So now we have the two electrons traveling all the way to this cathode. |
Fuel Cells .txt | Now, when it travels through this guy, this guy provides electricity to some outside source. |
Fuel Cells .txt | This is where the electrical work is done. |
Fuel Cells .txt | Now, when this electron or two electrons travel all the way down to this cathode. |
Fuel Cells .txt | These electrons react with the oxygen molecule, reducing it. |
Fuel Cells .txt | But notice that in order for this build up of H plus ions not to occur, these H plus ions must pass to this side. |
Fuel Cells .txt | So this, in a way, acts as a sole bridge because if this membrane wasn't here, we'd have a build up of positive charge here and a lack of positive charge here. |
Fuel Cells .txt | And then that means our electrons will stop flowing. |
Fuel Cells .txt | So to close the circuit, we need this membrane. |
Fuel Cells .txt | And so these H plus ions travel from the anode to the cathode. |
Fuel Cells .txt | And when they reach this position, they react with the oxygen and the electrons forming water. |
Fuel Cells .txt | Now, this water needs to be released somewhere because if the water remains, there's a build up of water and now cell would eventually stop functioning. |
Fuel Cells .txt | So this water leaves through some outside pump and is stored somewhere else. |
Fuel Cells .txt | Now, notice, the same way we need to allow H two molecules inside our ano, we need to allow o two molecules inside our capital. |