zeroth law of thermodynamics oh look around somebody help her out zero with love thermodynamics yes heat will flow until two objects in thermal contact have the same temperature see she did help you out brooke oh your never mind we'll come back to you kimberly first law of thermodynamics energy is conserved otherwise known as you can't win right there's nothing you can do with your thermodynamic cycles where you'll get more work out than than what uh q you put in it no uh-uh about three times in my career i've gotten the letter or the phone call or the email from somebody saying oh please review my device because i think i found a way to and you go no i'm not going to do that because it no first law of thermodynamics right so then today we're going to move ryan to the second law of thermodynamics okay um in in the gambler terms right the first laws you can't win what we're going to start to see when we look at the second law of thermodynamics is you can't even break even everything you do you lose okay yes everything you do cost you energy somehow and oh yeah reminder uh robin don't forget to check moodle because that's where i posted the corrections to the formula and where i posted the worked out end of example end of lecture example last time right so everybody should not emma yes i will go to moodle i go to moodle regularly i will find that on moodle and the biggest difference is that uh in the lecture i conflated two equations trying to make life simpler for you the correct equation is pv gamma not pv gamma minus 1. so i've said it a lot of times if you have your formula sheet with you i would fix that right now or i would go back in in the notes that you have and draw a big circle around it and say pv gamma is a constant not pv gamma minus one no minus one i'm just looking everybody's got it can i move the slide yeah all right so um shelby uh the the the book gives us two versions of the second law i find them both a little complicated but we'll talk about them for a couple of minutes here heat transfer occurs spontaneously from higher lower temperature bodies but never spontaneously in the reverse direction right while it is while it conserves energy if you put cold ice cubes in warm iced tea you never ever see the ice tea get warmer yet and more ice form it just it doesn't right no what do you see you see energy go from the ice tea making it colder into the ice cube making it warmer right always it never spontaneously goes the other direction it's you know like the conservation of energy law at some point you guess well why is energy conserved we could ask why is this true um for now we're just going to accept it okay all right um the other way that it's phrased bailey uh it's impossible in any system for heat transfer from a reservoir to completely convert to work in a cyclical process in which the system returns to its initial state man there are a lot of words in there yes we're going to in the slides to come deal with two very theoretical objects one is the heat engine and one is the heat pump do you own a heat engine yeah do you drive yes if you own a car you own a heat engine okay uh do you own a heat pump you might not own a heat pump yet but i bet you have access to one it keeps your full keeps your food cold right fancy name for a refrigerator or an air conditioning unit some of you may have parents that have heat pumps to heat the house anybody no no heat pumps well you can you can buy them but both of these things basically say you you can't even break even it's going to cost you energy to move energy whether you move that energy from water to ice or whether you move it from gasoline into motion or whether you move it from electricity into cold air it's going to cost you okay there's no there's no such thing as free