Some of you are looking at going to college or you are in a college in the Midwest and you first went there you're like oh it's fall it's beautiful everything's great and then February then so it's the October and then November and then December and then January hits and then what you notice is that you didn't know the thermometer actually went down that far. So what's happening out here so now we have these were below zero in negative temperatures so I grew up in the Midwest and so I've had seen negative four degrees Fahrenheit multiple times I then I carried a count so what is that in Celsius. Here's our formula again so I'm going to have negative four minus 32 times five nights and that's going to give me my degrees Celsius and then that turns out to be. Man, that turns out to be negative 36 so negative 36 C that's cold. However, in the future videos you'll find that we see the temperature is related to the amount of energy that's in a gas or in a system so William Thompson you know him as Lord Kelvin said this if energy of temperatures related to energy we can't have negative temperatures it's a terrible idea. So let's come over the different scale so he began to look at different gases and look at their pressures holding their volumes constant he would look at the temperatures so this was about 200 and then negative 100 negative 200 so forth so you have you'd have one gas that would have these data points that would be there. And then you would go okay well it's the strongest thing I got so look it's I'm going to end up with some sort of negative it keeps going oops and when your hands are terrible. I keep going crosses this zero pressure because once they get to these negative pressures negative pressure that's not really a thing so that doesn't exist so I should have zero pressure at some place out here but we'll have another gas so we have a different gas and so this gas is going to be something. It's kind of getting these pressure values here and now when I go to measure this stuff I can see that ends up being well I'm really bad. So there you go let's put some more data points back it. That that crosses almost the same size things that will be tried another one maybe these other ones that are out here so I'm. Then we put this gets this data points here and then extrapolates them back but he finds is they're all crossing at the same spot down here where they're all going to end up at some zero pressure this turns out to be negative 273 I think 0.171.5.5 degrees Celsius this is what he called absolute zero. Because at this point the pressure is zero the little molecules are not wiggling anymore for just sitting still and so he said you know what this should be this is here is a consistent fiduciary point it's not dependent on what pressure I'm at what liquid I'm boiling if there's any impurities in this stuff it's just a fundamental piece of the universe but you know the other thing you really like. The other thing you really liked is that there were 100 degrees from water for from freezing to boiling of water. So he liked the Celsius degree and so one Kelvin is the same size as one the absolute the magnitudes are the same but Kelvin is Celsius degrees I'm sorry degrees Celsius minus 273.15. So the same size but now you could do move them around and now they're not the Celsius has a degree on it that romer had a degree on it fair and high has a degree on it Kelvin does not so we just talk about things that being 200 Kelvin or 500 Kelvin or 700 Kelvin or whatever that happens to be. So there we go.