today we're going to finish up the last little bit of stuff that we're going to be talking about last little bit of stuff about the moon and then we're gonna move on and start talking about the earth and I think I forgot to mention this over the past couple of days but everything we're talking about this week is in Chapter two so if there's anything that you don't quite get from the lectures you can always go to chapter two to read up about the moon and the earth ok so let's talk about this the very everything that we talked about about the moon so far has just been stuff that stuff about how the moon looks right do eclipses really have an effect on your life no okay but there is one way that the that the moon actually physically affects the earth okay does anybody know what I'm talking about what's the one way that the moon has an actual physical effect on the earth itself and that's going to be our main topic of discussion um so not what it uses but what what is it's the tides okay it's the tides okay we'll get to how it does it in a second but yeah the tides let's talk about the tides first off we're talking about high tide when the water goes up and low tide when the water goes down right does anybody we live in Florida we're decently close to the to the ocean does anybody happen to know how many high tides there are in a day how many high tides are there in one 24-hour period how many high tides do we go twice yeah there's two two high tides every day so the water comes up twice every day and that means there must be two low tides every day also if the water comes up twice it's gonna go back down twice so two high tides every day two low tides every day what time a day do high tides happen what time do high tides happen this might be a trick question what time do high tides happen ah so somebody afternoon I see morning I see evening you could say night two it turns out if you're not very familiar with with the tides or with you know using boats or something like that you might not know this but high tides don't happen at the same time every day they're drastically different from one day to the next it's actually everyday the high tides are about 50 minutes later okay every day the high tides are about 50 minutes later and if you remember I mentioned that 50 minutes before there's something else that happens 50 minutes later every day that we talked about earlier in this week what what else happens 50 minutes later every day what is it it's related to the moon yet the moon rises 50 minutes later every day right every single day the moon rises 50 minutes later every day and the tides happen 50 minutes later every day and that's how we we realized that these things were related hundreds and hundreds of years ago specifically that means we basically noticed hundreds and hundreds and hundreds and hundreds and hundreds of years ago that whenever the moon was rising here's the moon rising every single time no matter what time of day the moon was rising when it was rising it was always low tide okay when the moon was rising it was low tide okay now after that point the moon came up in the sky and if we had low tide when it rose what's the water gonna do as the moon rises what is the water do as the Moon gets higher in the sky which way does the water go yeah Rises also right it rises so as the Moon moves from the horizon up the sky the water's gonna get higher and higher and higher and higher until here we go until we get the moon directly over our head and that's gonna be your high tide okay so at moon rises we're gonna get a low tide the water rises with the moon until the moon is directly above our head and that's gonna be our first high tide of that of that rotation right now um does anybody remember what we the fancy word for straight over your head what's the fancy word for straight over your head starts with a Z what's that so we get a high tide when the moon is at our yes at the zenith so when the moon is at the horizon we get a low tide and when it's at our Zenith we get a high tide okay okay now if we got a high tide when the moon's up here then the moon is eventually gonna start coming back down and then the water is gonna come back down can you tell when the next uh low-tide is gonna be when's the next low tide gonna be when the moon gets where or when the moon starts to do what another way to put it getting close yeah when the moon sets again right when the moon sets again you're gonna get another low tide okay so again low tide when the moon rises high tide when it sets your zenith and then another low tide when it sets but we're not done because that's our two low tides right low tide low tide low tide low tide but we only got one high tide so when's that where's the moon gonna be where are you gonna see the moon when the other high tide happens well the moon's just set where we gonna see the moon when the other high tide happens a little bit of a trick question on that one where are you gonna see the moon yeah mm-hmm got some people trying let's see what we get we can't see it right we can't see it because it's going to be on the exact opposite side of the planet as your Zenith okay so again when the moon came up over here we're getting a low tide sorry low tide high tide low tide and then when the moon goes directly under you it's going to be another high tide okay so two low tides low tide low tide high tide high tide right low tide low tide high tide high tide these are positions of the moon by the way I'm not just not just dancing over here so low tide low tide high tide high tide everybody good okay now check that's the that's the tide dance all right now here we go it took us a long long long time to figure out what the moon was actually doing and one of you guys have already actually mentioned this it wasn't until after Newton that we were able to figure out how the moon made the tides happen what is the moon using to make the tides happen how is the moon making the water come up when the moon's up here what's it using and the same thing over here yes it's using gravity right it's using gravity so Newton figured out that everything with mass has gravity and the moon has mass so until Newton figured that out we didn't know that the moon was pulling things like the earth pulls things and so the moon is able to pull on the water but let's think about this because there's a little bit of a confusing thing here okay because just saying gravity's not enough okay it makes sense that when the moon is up here it would pull the water up and we get a high tide that makes sense right it also makes sense if we get a low tide when the moon's over here because if the moon's over here it's gonna pull the water that way and if the water gets pulled that way it's basically causing our water on the on this part of the planet where we're standing to go down it's basically stealing our water sort of right same thing over here it pulls the water that way so it's a low tide for us cuz it's taking the water over there those ones make sense but when the moon is underneath us which way is it gonna pull the water don't worry about what kind of tide we get if the moon is under us which way should the water be pulled if the moon is using its gravity yeah the water should be pulled down right the water should be pulled down but we get a high tide meaning it looks like the water went up right so this part is confusing it's weird it doesn't seem to make a lot of sense that we get a high tide when the moon is under us because gravity doesn't push things away so what's happening here like I said it's a little bit more complicated let me draw some diagrams to help you understand it so check this out here we go here we go let's assume some mad scientist blew up the moon just blew the moon up okay just blew it up entirely while I'm drawing this if somebody blew up the moon entirely that just like vaporizer there's no moon left how many high tides would we have in a day how many high tides would we have with zero moons and I'll check back to see what you guys answer yeah we would have no ties that's correct we would have no tides at all so let's say oh come on I hate this machine that the school gave me let's uh restart it one more time here we go and there we go okay so let me zoom in a little bit so let's say that this is the earth I labeled it with an E for Earth and let's say that this is the ocean of the earth and real quick the ocean of the Earth is not that deep I'm drawing it much deeper than it really is just so we can see it better okay and let's say that the moon used to be up here like this is where the moon was okay and let's say that we decided oh that's bad we want to have a moon it's a bad idea all of our boats are stuck in the bay because there's no high tide to get the water level deep enough to get our boats out of the bay Oh No so we're going to create a new moon and just pop it right back in play like I don't know how we do this it's mad science we're just going to just pop a moon right there boom okay now here's the important part here's the important part Newton didn't just figured out that the moon has gravity he figured out some other things about gravity specifically that distance matters right the distance you are away from in this case the moon is going to determine how much gravity you feel okay so is every part of the earth and the ocean gonna feel the same amount of gravity no which part of the earth in ocean is going to feel the most gravity the moon when we turn the moon on which part on here will feel the most gravity from that moon the part closest to the moon that's correct the part that is closest to the moon so I'm just gonna put a number one on this ocean right here that ocean is the closest part of the earth to the moon when we turn the moon on the top right here yeah it's number one now the earth itself will feel the gravity of the moon but I'm gonna put a number two on the earth because it doesn't feel as much gravity as this ocean does because it's further away from where the moon's gonna be and then this ocean back here I'll put a three on it this part of the ocean because that's the farthest part away from the moon it's gonna feel the least amount of gravity but here's the important thing all of these parts are gonna feel gravity from the moon so when we turn the moon on which direction in this picture are all of these parts going to move they're all gonna move because of the moon's gravity and they're all being pulled by the moon so which way will they move on this picture up down left right in yeah they're all gonna move towards the moon up right up in this picture so every one of these parts will move up when we turn the moon on okay so let's say we turn the moon on well this is a moon off and let's say this is moon on over here so we're gonna turn the moon on and I need to draw all of these parts where they end up and I'm gonna exaggerate this like we said every part the entire Earth is actually going to move towards the moon when the moon is here the entire Earth is pulled a little bit in that okay when the moon is here the entire Earth is pulled a little bit in that direction but again you guys said that part one got the most pull of gravity and that means it's going to move the most okay part one is going to move the most so here we go let's imagine this ocean ended up way up here so it moved that much that was the pull that that ocean one received now oh oh sorry the earth itself also moves up but not as much because it doesn't get pulled as hard so the whole earth is actually going to end up moving up but it only got moved a medium amount that's part two that's the earth and then here we go don't overthink this which way is three gonna go also up but how much is three going to move up in this picture how much a lot a little bit a medium amount how much is three gonna move up not too much right not much at all just a little yeah so that means everybody's racing to get to the moon but ocean three kind of gets left behind it only moves up just a little bit but here we go here's the thing that means the water here got deeper and the water here got deeper those two parts of the water on our planet got deeper this one because it was ahead and this one because it was behind okay but there's only a certain amount of water so what's going to happen to the water on the sides where did this water have to come from what's going to happen to this water on the sides if the water got deeper in these two places what's gonna have to happen to this water over here on these sides yeah basically for the water to get deeper in these places the water had to come from somewhere so that means the water on the sides is going to get shallow because that's where the water was stolen from so essentially here's the thing everybody thinks of the earth and our ocean being a perfect circle like this but because of the pull of the moon we're actually stretched out a little bit I'm getting a little somes freezing here anyway the earth gets stretched out a little bit it's not nearly this extreme you probably have seen pictures of Earth from space and you probably didn't notice that we was stretched out a little bit like an egg but the earth itself and the oceans are stretched out like this now here we go let's put it all together if you were standing here what kind of tide would you have if that's you what kind of tide would you have right there high tide or low tide high tide you'd have a high tide if you're standing right there and don't overthink this which way would this person have to look to see that moon which we're in the sky would this person look to see the moon if he's standing right here up right towards their zenith right up that's correct you would also get a high tide if you were standing here and from this person's point of view where's the moon it's underneath their feet okay and then what kind of tide would you have over here what would this person have that would be a low tide right and which direction with this person right here which direction would this person look to see the moon where would they have to look in the sky to see the moon don't fight me my bandit cat just came in and bit my legs sorry guys yeah they would have to look off to their side right from their point of view the moon is to the side so they're looking at the horizon okay they're looking at the horizon so just like we said and it would be the same thing if you were standing over here so if the moon is to your side the water will be low if the moon is above your head you get a high tide and if the moon is below your feet you get a high tide so basically now we can really explain the high tides like this when the moon is above you it's okay to think the water on my side of the planet came up more than the earth went up so the water got high the water went up more than the earth did but if we were to turn this picture upside down from this person's point of view everything's being pulled down but the earth that you're standing on the floor got pulled down more than your water did so your water got left behind it's not that the water got pushed up it's just that the water got left behind when the ground went down that's the point of view on this side it's a little bit confusing to get into your head it's okay and finally last thing I want to say from this figure is this the reason that we get to highs and to lows every day is that it takes a whole month about four weeks for the moon to move all the way around the earth so that means in one day the moon is basically in the same place all day it just stays roughly there in its orbit but during that day what does the earth do while the moon's just hanging out up here what does the earth do every day physically here we go what does the earth do yet rotates it spins once a day so while the moon hangs out roughly in the same spot all day long the Earth spins once a day inside of this stretched out ocean and so that means you're going to spin through high tide low tide high tide low tide every day and then the next day the moon is moved over a little bit and so you're gonna hit those tides at a slightly different time and then the next day the moon is moved over a little bit again so if you remember a couple of days ago we learned how to use that figure to figure out when a moon is gonna rise and set that means if you know when a moon is rising you know when low tides are gonna be and if you know when the moon is gonna be over your head at your Zenith you know when the high tides are gonna be sorry guys my cat keeps biting me I think it's hungry but we're gonna keep going it's not time to eat yet it's not time to eat okay so just bear with this cat all right sorry case now here we go so that's the regular tides all right