1 00:00:08,440 --> 00:00:11,080 Speaker 1: Hey, Daniel, when you're at the beach, are you able 2 00:00:11,119 --> 00:00:13,600 Speaker 1: to relax and forget about physics for a minute. 3 00:00:13,920 --> 00:00:16,239 Speaker 2: You know, I love the beach. It's beautiful, but it's 4 00:00:16,280 --> 00:00:19,400 Speaker 2: actually kind of hard to forget about physics at the beach. 5 00:00:20,320 --> 00:00:22,599 Speaker 2: There's just so much physics happening right there in front 6 00:00:22,640 --> 00:00:25,880 Speaker 2: of your eyes. The surf, the tides, the shimmering sunlight. 7 00:00:26,280 --> 00:00:28,520 Speaker 1: It sounds like physics is burnt into your brain. 8 00:00:29,840 --> 00:00:31,880 Speaker 2: No, it's just the physics is all around us. 9 00:00:31,960 --> 00:00:32,159 Speaker 3: You know. 10 00:00:32,240 --> 00:00:35,280 Speaker 2: The moon is up there in the sky literally squeezing 11 00:00:35,280 --> 00:00:36,760 Speaker 2: the planet with its gravity. 12 00:00:36,880 --> 00:00:39,239 Speaker 1: Yeah, it sounds like you need some physics sunblock there 13 00:00:39,240 --> 00:00:39,760 Speaker 1: for your brain. 14 00:00:40,920 --> 00:00:43,080 Speaker 2: I think you might have to just extract my whole brain. 15 00:00:43,200 --> 00:00:43,960 Speaker 1: Feed it to the fish. 16 00:00:43,960 --> 00:00:44,760 Speaker 2: It's good for something. 17 00:00:44,760 --> 00:00:47,360 Speaker 1: I hope maybe the fish will get smarter. There'll be fishes. 18 00:01:03,720 --> 00:01:06,479 Speaker 1: Him form a cartoonist and the author of Oliver's Great 19 00:01:06,560 --> 00:01:07,280 Speaker 1: Big Universe. 20 00:01:07,400 --> 00:01:10,160 Speaker 2: Hi, I'm Daniel. I'm a particle physicist and a professor. 21 00:01:10,400 --> 00:01:12,840 Speaker 2: You see irvine down here on the coast. But I 22 00:01:12,920 --> 00:01:15,520 Speaker 2: hope not to end up as fish food eventually. 23 00:01:15,640 --> 00:01:18,920 Speaker 1: Aren't we all fish food or warm food? Which would 24 00:01:18,959 --> 00:01:22,160 Speaker 1: you prefer to be eaten by worms? Or fish or 25 00:01:22,200 --> 00:01:29,800 Speaker 1: aliens aliens, But you'll be you'll be food. You won't 26 00:01:29,840 --> 00:01:30,880 Speaker 1: really have a preference by them. 27 00:01:31,080 --> 00:01:32,440 Speaker 2: Yeah, but you know, as long as they send me 28 00:01:32,520 --> 00:01:34,920 Speaker 2: some secrets to the universe before they fry me up 29 00:01:34,959 --> 00:01:36,520 Speaker 2: for dinner, we're all cool. Nice. 30 00:01:36,640 --> 00:01:39,000 Speaker 1: It's all about the legacy and what do you know 31 00:01:39,280 --> 00:01:41,360 Speaker 1: right before you become dinner. 32 00:01:41,560 --> 00:01:44,759 Speaker 2: Yes, it's a huge difference to die knowing the answers 33 00:01:44,840 --> 00:01:47,040 Speaker 2: to the secrets of the universe and not. 34 00:01:47,440 --> 00:01:49,040 Speaker 1: I wonder, though, if your brain is full of all 35 00:01:49,120 --> 00:01:51,880 Speaker 1: his knowledge, would you cause the aliens indigestion? 36 00:01:52,280 --> 00:01:55,520 Speaker 2: No? I think I taste better. That's why they should 37 00:01:55,560 --> 00:01:55,800 Speaker 2: tell me. 38 00:01:55,960 --> 00:01:58,160 Speaker 1: Sor you'll be juicier. You'll be juicier with knowledge. 39 00:01:59,400 --> 00:02:01,840 Speaker 2: I mean, I'll be happier, which probably makes me taste better. 40 00:02:02,000 --> 00:02:02,360 Speaker 2: I don't know. 41 00:02:03,000 --> 00:02:06,080 Speaker 1: Maybe happiness tastes bitter to the aliens. Maybe I prefer 42 00:02:06,160 --> 00:02:07,480 Speaker 1: people who don't know a lot of things. 43 00:02:07,680 --> 00:02:10,280 Speaker 2: In that case, physics is my survival strategy for when 44 00:02:10,280 --> 00:02:11,079 Speaker 2: the aliens arrive. 45 00:02:11,160 --> 00:02:13,000 Speaker 1: Taste like a nerd, so nobody wants to eat you. 46 00:02:13,720 --> 00:02:15,120 Speaker 2: Don't eat me, I'm dorky. 47 00:02:15,160 --> 00:02:18,320 Speaker 1: Taste don't eat me. I'm a geek. But anyways, welcome 48 00:02:18,320 --> 00:02:20,760 Speaker 1: to our podcast Daniel and Jorge Explain the Universe, a 49 00:02:20,840 --> 00:02:23,000 Speaker 1: production of iHeartRadio. 50 00:02:22,480 --> 00:02:25,520 Speaker 2: In which we do our best to make you filled 51 00:02:25,600 --> 00:02:28,639 Speaker 2: with knowledge so that you are less tasty to the aliens, 52 00:02:28,800 --> 00:02:32,480 Speaker 2: or whichever direction that goes. We think that everything out 53 00:02:32,480 --> 00:02:35,160 Speaker 2: there in the universe can and should be understood, and 54 00:02:35,240 --> 00:02:39,200 Speaker 2: that everybody out there on Earth is capable of understanding it. 55 00:02:39,320 --> 00:02:41,160 Speaker 2: And we want to share with you that joyous moment 56 00:02:41,240 --> 00:02:44,040 Speaker 2: when the idea is click into your head and you go, Aha, 57 00:02:44,480 --> 00:02:45,720 Speaker 2: that's how it all works. 58 00:02:46,200 --> 00:02:48,440 Speaker 1: That's right. We like to serve up the entire universe 59 00:02:48,480 --> 00:02:50,639 Speaker 1: to you on a plate and fill you up with 60 00:02:50,760 --> 00:02:54,000 Speaker 1: amazing facts and knowledge about how the universe works, what 61 00:02:54,200 --> 00:02:57,239 Speaker 1: makes it all tick, and what moves the Earth and 62 00:02:57,360 --> 00:02:59,520 Speaker 1: the oceans out there around us. 63 00:03:00,040 --> 00:03:02,200 Speaker 2: Some of the deepest questions in physics have to do 64 00:03:02,320 --> 00:03:05,120 Speaker 2: with what's happening and the objects really far away at 65 00:03:05,120 --> 00:03:08,280 Speaker 2: the hearts of neutron stars or black holes. Some of 66 00:03:08,320 --> 00:03:11,320 Speaker 2: them have to do with particles between our toes and 67 00:03:11,480 --> 00:03:13,760 Speaker 2: how they wiggle and dance and to and fro to 68 00:03:13,880 --> 00:03:17,760 Speaker 2: make our reality. Sometimes these questions are connected, and what's 69 00:03:17,800 --> 00:03:20,880 Speaker 2: happening up there in the cosmos affects things down here 70 00:03:21,000 --> 00:03:21,480 Speaker 2: on Earth. 71 00:03:21,639 --> 00:03:24,679 Speaker 1: Yeah, it's right. We are surrounded by invisible forces that 72 00:03:24,960 --> 00:03:28,600 Speaker 1: move the things around us, that cost the weather, the earthquakes, 73 00:03:28,720 --> 00:03:31,680 Speaker 1: the magnetic field around us, and also the tides. 74 00:03:32,040 --> 00:03:34,720 Speaker 2: The deep history of physics is just people trying to 75 00:03:35,080 --> 00:03:38,560 Speaker 2: understand everything they see. Why does it rain? Why does 76 00:03:38,600 --> 00:03:41,680 Speaker 2: the sun rise? Why does the water rise and fall? 77 00:03:42,200 --> 00:03:44,960 Speaker 2: Is it possible to understand everything that's happening to us 78 00:03:45,040 --> 00:03:48,560 Speaker 2: in terms of some like clockwork mechanistic system. If we 79 00:03:48,720 --> 00:03:52,120 Speaker 2: make our understanding complex enough, can we predict even the 80 00:03:52,240 --> 00:03:53,600 Speaker 2: rise and fall of the ocean? 81 00:03:53,840 --> 00:03:55,760 Speaker 1: And so today on the podcast we'll be tackling the 82 00:03:55,840 --> 00:04:05,360 Speaker 1: question what are land tides now, Daniel, We're not talking 83 00:04:05,360 --> 00:04:08,400 Speaker 1: about like the closed laundry detergent, are we like the 84 00:04:08,480 --> 00:04:12,360 Speaker 1: kind of gets dirt out of your clothes tide pods? 85 00:04:12,680 --> 00:04:16,240 Speaker 2: I think given the poor history of physics naming things, 86 00:04:16,400 --> 00:04:19,280 Speaker 2: we should be pretty careful drawing conclusions just from the 87 00:04:19,360 --> 00:04:20,200 Speaker 2: name of this effect. 88 00:04:20,360 --> 00:04:22,839 Speaker 1: Oh so it is possible to a laundry episode. 89 00:04:24,720 --> 00:04:27,320 Speaker 2: This episode might be like pouring detergent on your brain. 90 00:04:27,480 --> 00:04:30,200 Speaker 1: Yes, we're airing out the dirty laundry of physics here. 91 00:04:31,480 --> 00:04:32,960 Speaker 2: No, In fact, I think this is a topic which 92 00:04:33,040 --> 00:04:35,200 Speaker 2: is actually probably pretty well named. 93 00:04:35,480 --> 00:04:38,160 Speaker 1: Oh yes, sometimes it's well named. Sometimes it's not well named. 94 00:04:38,279 --> 00:04:40,320 Speaker 2: Sometimes the quality of the naming ebbs and. 95 00:04:40,400 --> 00:04:42,760 Speaker 1: Flows, that's right, And sometimes we like to serve that 96 00:04:42,880 --> 00:04:45,720 Speaker 1: wave hopefully get to a place where we understand more 97 00:04:45,760 --> 00:04:48,680 Speaker 1: about the universe and our whole planet. And so this 98 00:04:48,800 --> 00:04:51,080 Speaker 1: is I guess something that is happening here on Earth, 99 00:04:51,160 --> 00:04:51,800 Speaker 1: Daniel right. 100 00:04:52,200 --> 00:04:54,480 Speaker 2: Land tides are happening here on Earth. They're happening on 101 00:04:54,520 --> 00:04:56,479 Speaker 2: the Moon, They're happening on every planet we. 102 00:04:56,640 --> 00:04:59,679 Speaker 1: Know of whoa interesting, even the gas planets. 103 00:05:00,160 --> 00:05:04,080 Speaker 2: I guess they're probably having gas tides. I think there's 104 00:05:04,120 --> 00:05:05,200 Speaker 2: medication you can take for that. 105 00:05:05,279 --> 00:05:07,400 Speaker 1: All right, Well, it's an interesting question, and so, as usually, 106 00:05:07,480 --> 00:05:09,080 Speaker 1: we were wondering how many people out there had thought 107 00:05:09,120 --> 00:05:11,880 Speaker 1: about the idea of tides on land. 108 00:05:12,200 --> 00:05:15,760 Speaker 2: Thanks to everybody who volunteers for this audience participation segment. 109 00:05:15,839 --> 00:05:18,920 Speaker 2: We'd love to hear your voice on our podcast, so 110 00:05:19,040 --> 00:05:21,679 Speaker 2: please write to me two questions at Daniel and Jorge 111 00:05:21,800 --> 00:05:23,360 Speaker 2: dot com if you'd like to play. 112 00:05:23,520 --> 00:05:25,080 Speaker 1: So think about it for a second. What do you 113 00:05:25,160 --> 00:05:28,720 Speaker 1: think of when you hear the words land tides? Here's 114 00:05:28,760 --> 00:05:29,799 Speaker 1: what people had to say. 115 00:05:29,839 --> 00:05:33,920 Speaker 2: Well, we all know what sea tides are I guess 116 00:05:34,040 --> 00:05:39,239 Speaker 2: it's probably the same effect, but not pulling water, pulling land. 117 00:05:40,320 --> 00:05:43,120 Speaker 1: Maybe some land that behaves a little bit like water. 118 00:05:43,279 --> 00:05:43,640 Speaker 1: I don't know. 119 00:05:43,839 --> 00:05:46,880 Speaker 2: Maybe there are tides in the Sahara Desert that. 120 00:05:47,000 --> 00:05:50,400 Speaker 4: Makes me think of the ocean tide. So the water 121 00:05:50,520 --> 00:05:53,200 Speaker 4: being pulled by the Moon. I know, the Earth is 122 00:05:53,279 --> 00:05:56,719 Speaker 4: kind of being squished a bit from it's not perfectly round, 123 00:05:57,320 --> 00:06:00,880 Speaker 4: from the gravitational forces and centrifugal force and things like that. 124 00:06:01,760 --> 00:06:03,920 Speaker 4: So I'm going to guess that that's part of all 125 00:06:03,960 --> 00:06:08,800 Speaker 4: that together, Especially gravity due to the Moon, the Sun, 126 00:06:09,160 --> 00:06:13,920 Speaker 4: other you know, astrological bodies all contribute to the land 127 00:06:13,960 --> 00:06:14,320 Speaker 4: of moving. 128 00:06:14,760 --> 00:06:18,000 Speaker 3: I haven't heard of land tides before, but I would 129 00:06:18,040 --> 00:06:22,400 Speaker 3: imagine that they are similar to ocean tides, where the 130 00:06:22,640 --> 00:06:27,360 Speaker 3: Moon's gravity affects the surface of the Earth, just on 131 00:06:27,560 --> 00:06:28,919 Speaker 3: land instead of on the ocean. 132 00:06:29,360 --> 00:06:32,120 Speaker 2: If I had to guess, I would say the effects 133 00:06:32,200 --> 00:06:35,720 Speaker 2: of tidal force from the Moon non plate tectonics. 134 00:06:36,320 --> 00:06:41,160 Speaker 1: Seems a little bit straightforward sounding. Perhaps tides related to 135 00:06:41,200 --> 00:06:41,600 Speaker 1: the land. 136 00:06:42,120 --> 00:06:45,080 Speaker 2: Yeah, exactly. The name seems to convey basically. 137 00:06:44,760 --> 00:06:45,160 Speaker 3: What it is. 138 00:06:45,279 --> 00:06:47,839 Speaker 1: Sounds like I'm the only one who thought about laundry detergent. 139 00:06:48,640 --> 00:06:50,800 Speaker 1: Might be because it's time for me to do laundry. 140 00:06:51,720 --> 00:06:53,880 Speaker 1: The tidy my laundry basket is getting a little high. 141 00:06:53,960 --> 00:06:55,320 Speaker 2: You have a big stack of pajamas. 142 00:06:55,760 --> 00:06:57,800 Speaker 1: That's right, my daily uniform. 143 00:06:59,120 --> 00:07:02,039 Speaker 2: It's growing so long that it has its own gravitational pull, 144 00:07:02,360 --> 00:07:04,440 Speaker 2: and so it's got some tide inside your house. 145 00:07:04,560 --> 00:07:04,880 Speaker 3: That's right. 146 00:07:05,080 --> 00:07:08,800 Speaker 1: It's causing the tide of bananas to evan flow just 147 00:07:08,880 --> 00:07:11,040 Speaker 1: from the sheer gravity of its size. 148 00:07:11,200 --> 00:07:13,320 Speaker 2: It might cause some marital tides if you're arguing about 149 00:07:13,320 --> 00:07:14,440 Speaker 2: who's going to do that laundry. 150 00:07:14,640 --> 00:07:17,080 Speaker 1: Yeah, yeah, yeah, but then it all tides over, so 151 00:07:17,320 --> 00:07:20,400 Speaker 1: it's all good. Well, let's talk about tides in general, 152 00:07:20,840 --> 00:07:22,800 Speaker 1: and we'll get to land tides, but first and maybe 153 00:07:22,840 --> 00:07:25,480 Speaker 1: let's talk about the regular tides most people are familiar with, 154 00:07:25,800 --> 00:07:28,920 Speaker 1: which are ocean tides or the tides in the sea. 155 00:07:29,400 --> 00:07:31,760 Speaker 2: Yeah, because it turns out that land tides and ocean 156 00:07:31,840 --> 00:07:35,200 Speaker 2: tides are pretty intimately connected. So you've got to understand 157 00:07:35,240 --> 00:07:40,160 Speaker 2: ocean tides first. Ocean tides come from tidal forces. That's 158 00:07:40,240 --> 00:07:42,520 Speaker 2: how they get their name. And tidal forces are just 159 00:07:42,560 --> 00:07:46,440 Speaker 2: an effective gravity and of objects not being point masses, 160 00:07:46,800 --> 00:07:50,560 Speaker 2: of things actually being like extended spheres, so the gravity varies. 161 00:07:50,960 --> 00:07:53,240 Speaker 2: I mean that gravity gets weaker or stronger as you 162 00:07:53,360 --> 00:07:56,080 Speaker 2: get further or closer to something. And so if you're 163 00:07:56,080 --> 00:07:58,240 Speaker 2: in different places on the Earth, for example, you're going 164 00:07:58,320 --> 00:08:01,040 Speaker 2: to feel the Sun's gravity or the Mund's gravity with 165 00:08:01,160 --> 00:08:02,040 Speaker 2: a different strength. 166 00:08:02,120 --> 00:08:04,120 Speaker 1: Well, let's maybe take a step back here and talk 167 00:08:04,160 --> 00:08:07,160 Speaker 1: about what tides are. So like, if you're at the beach, 168 00:08:07,600 --> 00:08:10,240 Speaker 1: the tide just means that the general, the average level 169 00:08:10,280 --> 00:08:11,720 Speaker 1: of the ocean goes up and down. 170 00:08:11,960 --> 00:08:13,920 Speaker 2: Yeah, when we talk about tides, we usually mean the 171 00:08:14,000 --> 00:08:16,960 Speaker 2: ocean tides, and yeah, the ocean goes up and it 172 00:08:17,040 --> 00:08:19,240 Speaker 2: goes down. Like if you're at the beach, sometimes the 173 00:08:19,320 --> 00:08:22,040 Speaker 2: water rises up higher than it does other times. And 174 00:08:22,080 --> 00:08:23,680 Speaker 2: you might notice when you're sitting there on the sand, 175 00:08:23,760 --> 00:08:26,360 Speaker 2: you take a nap and you wake up, Oops, you're underwater. 176 00:08:27,000 --> 00:08:29,160 Speaker 2: And that's not because of a rogue wave. It's because 177 00:08:29,200 --> 00:08:31,720 Speaker 2: the overall level of the ocean has risen. 178 00:08:32,480 --> 00:08:34,880 Speaker 1: When do you think humans first noticed this? Probably the 179 00:08:34,920 --> 00:08:36,480 Speaker 1: first time they reached the beach, right. 180 00:08:36,840 --> 00:08:39,240 Speaker 2: Yeah, I think people have always noticed this. I mean 181 00:08:39,280 --> 00:08:41,360 Speaker 2: people have been living on the beach in southern California 182 00:08:41,440 --> 00:08:44,400 Speaker 2: for tens of thousands of years and so pretty sure 183 00:08:44,520 --> 00:08:45,920 Speaker 2: tides were part of their life. 184 00:08:45,760 --> 00:08:47,640 Speaker 1: Right, But I imagine they started in the beaches of 185 00:08:47,840 --> 00:08:49,120 Speaker 1: Africa perhaps. 186 00:08:49,000 --> 00:08:52,200 Speaker 2: Oh yeah, absolutely, there's tides on every shore around the world. 187 00:08:52,840 --> 00:08:54,360 Speaker 1: And now does it depend on the size of the 188 00:08:54,679 --> 00:08:57,160 Speaker 1: body of water, Like is it bigger in some oceans 189 00:08:57,280 --> 00:08:58,840 Speaker 1: or lakes? Does it happen in a lake. 190 00:08:59,120 --> 00:09:02,040 Speaker 2: It turns out to be quite complicated the size of 191 00:09:02,200 --> 00:09:05,679 Speaker 2: the tides. It depends on not just the depth of 192 00:09:05,720 --> 00:09:08,280 Speaker 2: the ocean and the size of the body of water, 193 00:09:08,600 --> 00:09:11,199 Speaker 2: but also like the shape of the harbor and the 194 00:09:11,280 --> 00:09:14,560 Speaker 2: shape of the land nearby. There's all sorts of complicated 195 00:09:14,640 --> 00:09:17,599 Speaker 2: effects that change how the ocean water goes up and 196 00:09:17,679 --> 00:09:20,040 Speaker 2: down at a particular point on the shore. 197 00:09:20,840 --> 00:09:22,520 Speaker 1: All right, Well, let's dig into the physics. You said 198 00:09:22,520 --> 00:09:24,760 Speaker 1: it's sort of related to the gravity of the moon. 199 00:09:25,080 --> 00:09:27,680 Speaker 2: The reason the ocean goes up and down is mostly 200 00:09:27,840 --> 00:09:30,599 Speaker 2: because of the moon, also because of the Sun. The 201 00:09:30,679 --> 00:09:33,560 Speaker 2: physics that underlies it is what we call tidal forces. 202 00:09:33,840 --> 00:09:35,520 Speaker 2: If the moon is pulling on you, then it pulls 203 00:09:35,559 --> 00:09:37,439 Speaker 2: on you harder. If you're on a spot on the 204 00:09:37,559 --> 00:09:39,679 Speaker 2: Earth it's closer to the Moon than if you're on 205 00:09:39,760 --> 00:09:41,240 Speaker 2: the other side of the Earth. 206 00:09:41,480 --> 00:09:43,640 Speaker 1: And that's because that's just how gravity works, right. 207 00:09:43,800 --> 00:09:46,480 Speaker 2: Yeah, that's how gravity works. The closer you are the 208 00:09:46,559 --> 00:09:49,120 Speaker 2: heart of the force. So physicists tend to like to 209 00:09:49,240 --> 00:09:52,000 Speaker 2: think about planets as point particles or Earth is just 210 00:09:52,120 --> 00:09:54,320 Speaker 2: like a dot that has the mass of the Earth 211 00:09:54,440 --> 00:09:56,520 Speaker 2: at its center of mass, and we think about the 212 00:09:56,640 --> 00:10:00,480 Speaker 2: motion of the Earth using fat But in actuality, every 213 00:10:00,559 --> 00:10:03,480 Speaker 2: place on the Earth feels a different tug from the 214 00:10:03,559 --> 00:10:06,760 Speaker 2: Moon because they're all at different distances and different angles. 215 00:10:06,840 --> 00:10:08,800 Speaker 1: Right Like, if you were just out there in space, 216 00:10:09,000 --> 00:10:10,680 Speaker 1: if you were closer to the Moon, you would feel 217 00:10:10,720 --> 00:10:12,720 Speaker 1: a stronger pull towards the Moon than if you were 218 00:10:12,880 --> 00:10:15,280 Speaker 1: farther away from the Moon. And so the same thing 219 00:10:15,320 --> 00:10:17,000 Speaker 1: happens to all the points around the Earth. 220 00:10:17,360 --> 00:10:19,360 Speaker 2: The same thing happens to all the points around the Earth. 221 00:10:19,720 --> 00:10:21,880 Speaker 2: And this isn't just connected to the Moon or to 222 00:10:21,960 --> 00:10:25,199 Speaker 2: the Sun. It happens for everything that's gravitational. We talk 223 00:10:25,240 --> 00:10:27,840 Speaker 2: about it in the context of black holes because black 224 00:10:27,840 --> 00:10:30,800 Speaker 2: holes are extremely strong gravity. If you get too close 225 00:10:30,840 --> 00:10:33,440 Speaker 2: to them, then the difference between the gravity on your 226 00:10:33,480 --> 00:10:35,760 Speaker 2: feet and on your head might be strong enough to 227 00:10:35,800 --> 00:10:39,439 Speaker 2: pull you apart. That's the origin of spaghetification. It's just 228 00:10:39,640 --> 00:10:42,160 Speaker 2: tidal forces. The fact that you're not a point particle. 229 00:10:42,320 --> 00:10:44,160 Speaker 2: If you're just a point particle, there'd be one force 230 00:10:44,240 --> 00:10:46,959 Speaker 2: of gravity on you. But because you're an extended object 231 00:10:47,320 --> 00:10:49,599 Speaker 2: with different distances from the black hole or from the 232 00:10:49,679 --> 00:10:52,199 Speaker 2: Moon or from the Sun, you feel different forces of 233 00:10:52,280 --> 00:10:54,240 Speaker 2: gravity at different points on your body. 234 00:10:54,640 --> 00:10:57,559 Speaker 1: Interesting. So then where does the word title come in? 235 00:10:57,760 --> 00:10:59,920 Speaker 2: Oh, the word title comes in because this is base 236 00:11:00,280 --> 00:11:03,360 Speaker 2: an explanation for the ocean tides. So that's why we 237 00:11:03,440 --> 00:11:04,800 Speaker 2: call them tidal forces, all. 238 00:11:04,760 --> 00:11:07,199 Speaker 1: Right, So then how does the moon cause the tides 239 00:11:07,200 --> 00:11:07,679 Speaker 1: in the ocean? 240 00:11:08,040 --> 00:11:10,160 Speaker 2: So the way to think about tidal forces is to 241 00:11:10,200 --> 00:11:12,880 Speaker 2: think about how the force of gravity on you is 242 00:11:13,000 --> 00:11:15,760 Speaker 2: different than if you were at the center of the Earth. 243 00:11:16,080 --> 00:11:17,240 Speaker 2: The center of the Earth is sort of like the 244 00:11:17,320 --> 00:11:19,560 Speaker 2: reference gravity. If you're at the center of the Earth, 245 00:11:19,600 --> 00:11:21,559 Speaker 2: what would be the gravity of the moon. And then 246 00:11:21,600 --> 00:11:23,319 Speaker 2: as you move around the surface of the Earth, you 247 00:11:23,400 --> 00:11:25,439 Speaker 2: can ask how is my gravity different than if I 248 00:11:25,640 --> 00:11:27,560 Speaker 2: was at the center of the Earth. And so if 249 00:11:27,600 --> 00:11:29,920 Speaker 2: you're on a point on the Earth that's closer to 250 00:11:30,000 --> 00:11:32,320 Speaker 2: the Moon than the center, then you're going to feel 251 00:11:32,360 --> 00:11:35,480 Speaker 2: stronger gravity towards the Moon. If you're on the other 252 00:11:35,679 --> 00:11:38,160 Speaker 2: side of the Earth. Now you're farther from the Moon, 253 00:11:38,559 --> 00:11:41,680 Speaker 2: you're going to feel weaker gravity. So the tidal force 254 00:11:41,840 --> 00:11:44,199 Speaker 2: is the difference. So what that means is that on 255 00:11:44,280 --> 00:11:46,839 Speaker 2: the closer side of the Earth, there's basically a tidal 256 00:11:46,920 --> 00:11:49,599 Speaker 2: force towards the Moon, and on the distant side of 257 00:11:49,640 --> 00:11:52,280 Speaker 2: the Earth is a tidal force away from the moon. 258 00:11:52,360 --> 00:11:55,720 Speaker 1: Oh why is it away? And I still being pulled 259 00:11:55,760 --> 00:11:58,520 Speaker 1: towards the moon even if I'm on the far side 260 00:11:58,559 --> 00:11:58,960 Speaker 1: of the Earth. 261 00:12:00,040 --> 00:12:02,280 Speaker 2: Are still being pulled towards the moon. The force of 262 00:12:02,320 --> 00:12:04,520 Speaker 2: gravity is towards the Moon, but it's less than the 263 00:12:04,559 --> 00:12:06,719 Speaker 2: force of gravity you would feel at the center of 264 00:12:06,800 --> 00:12:09,080 Speaker 2: the Earth. So relative to the force of the center 265 00:12:09,080 --> 00:12:11,800 Speaker 2: of the Earth, the tidal force is away from the Moon. 266 00:12:12,000 --> 00:12:13,920 Speaker 1: I see, you're being pulled less than the center. So 267 00:12:14,120 --> 00:12:16,200 Speaker 1: in a way, you're being pulled away from the center 268 00:12:16,320 --> 00:12:17,320 Speaker 1: of the Earth exactly. 269 00:12:17,360 --> 00:12:20,080 Speaker 2: And that's all we usually talk about, how one part 270 00:12:20,160 --> 00:12:22,480 Speaker 2: is being pulled towards and one part is effectively being 271 00:12:22,520 --> 00:12:25,480 Speaker 2: pulled away in a relative sense. But this also sort 272 00:12:25,520 --> 00:12:28,960 Speaker 2: of sideways tidal forces. If you're at a point along 273 00:12:29,040 --> 00:12:32,000 Speaker 2: a circle that's between the point that's closest to the 274 00:12:32,080 --> 00:12:34,640 Speaker 2: Moon and the point that's furthest from the Moon. Then 275 00:12:34,679 --> 00:12:37,599 Speaker 2: the effective tidal forces are towards the center of the 276 00:12:37,720 --> 00:12:40,200 Speaker 2: Earth because the Moon is pulling you not just towards 277 00:12:40,240 --> 00:12:43,040 Speaker 2: the Moon, but also basically towards the center of the Earth. 278 00:12:43,160 --> 00:12:46,160 Speaker 1: So, for example, like the moon sort of rotates around 279 00:12:46,200 --> 00:12:49,719 Speaker 1: the Earth sort of along the equator line more or less, right, 280 00:12:50,240 --> 00:12:52,280 Speaker 1: Like that's the kind of the circle that goes around 281 00:12:52,360 --> 00:12:54,640 Speaker 1: and A. So you're saying, like the north and south 282 00:12:54,679 --> 00:12:58,520 Speaker 1: poles of the Earth are being pulled kind of towards 283 00:12:58,960 --> 00:13:00,240 Speaker 1: the equator basically. 284 00:13:00,120 --> 00:13:03,000 Speaker 2: Yeah, that's right. And so the overall effect is just 285 00:13:03,120 --> 00:13:05,800 Speaker 2: try to squeeze the Earth like into a football shape. 286 00:13:06,160 --> 00:13:09,360 Speaker 2: The closest part gets pulled closer, the furthest part gets 287 00:13:09,480 --> 00:13:12,880 Speaker 2: pulled less, and the center gets squeezed towards the center 288 00:13:12,960 --> 00:13:13,439 Speaker 2: of the Earth. 289 00:13:14,320 --> 00:13:16,360 Speaker 1: All right, So then the effect of the Moon is 290 00:13:16,400 --> 00:13:18,760 Speaker 1: to squish the Earth. It's not just like pulling at 291 00:13:18,800 --> 00:13:20,800 Speaker 1: the center of the Earth. It's like kind of pulling 292 00:13:20,840 --> 00:13:23,079 Speaker 1: out the Earth, but also kind of squishing it or 293 00:13:23,280 --> 00:13:25,520 Speaker 1: kind of trying to pull into a football shape. 294 00:13:25,679 --> 00:13:28,360 Speaker 2: Yeah, exactly, And this is all relative to how the 295 00:13:28,440 --> 00:13:30,280 Speaker 2: Moon would be pulling on the Earth. If it's just 296 00:13:30,440 --> 00:13:33,520 Speaker 2: like a point particle at the center of mass, because 297 00:13:33,520 --> 00:13:36,200 Speaker 2: the Earth isn't. The point particle has all these different 298 00:13:36,240 --> 00:13:39,199 Speaker 2: gravitational forces on it, and the effect is basically to 299 00:13:39,280 --> 00:13:40,640 Speaker 2: try to squeeze it into a football. 300 00:13:40,760 --> 00:13:42,440 Speaker 1: And the weird thing is that the Moon is moving 301 00:13:42,520 --> 00:13:44,760 Speaker 1: relative to the Earth, so it's like it's squeezing in 302 00:13:44,800 --> 00:13:46,760 Speaker 1: one moment, it's squeezing it in one direction to make 303 00:13:46,800 --> 00:13:49,120 Speaker 1: it look like football. But then as the Moon rotates, 304 00:13:49,240 --> 00:13:52,199 Speaker 1: then now all those forces changes, so it's almost like 305 00:13:52,240 --> 00:13:54,680 Speaker 1: you're massaging the Earth exactly. 306 00:13:54,920 --> 00:13:57,400 Speaker 2: You're massaging the Earth, and you're running circles around the 307 00:13:57,440 --> 00:14:00,640 Speaker 2: Earth at the same time, so you're always massaging different spots. 308 00:14:00,760 --> 00:14:02,240 Speaker 1: Yeah, it's a three sixty massage. 309 00:14:03,440 --> 00:14:05,719 Speaker 2: And that's the origin of the tidal patterns, right the 310 00:14:05,760 --> 00:14:08,400 Speaker 2: tides go up and the tides go down. Basically, the 311 00:14:08,520 --> 00:14:11,360 Speaker 2: water on the surface of the Earth gets pulled into 312 00:14:11,440 --> 00:14:14,360 Speaker 2: that football shape because water is much more flexible than 313 00:14:14,400 --> 00:14:16,760 Speaker 2: the earth is, So the water is deeper the conical 314 00:14:16,840 --> 00:14:20,360 Speaker 2: parts of that football and shallower at the edges of 315 00:14:20,400 --> 00:14:20,920 Speaker 2: the football. 316 00:14:21,120 --> 00:14:22,360 Speaker 1: What do you mean, it's more flexible. 317 00:14:22,480 --> 00:14:25,880 Speaker 2: It's easier to squeeze water than it is to squeeze granite. 318 00:14:26,000 --> 00:14:28,680 Speaker 1: Or in this case, you're saying it's easier to stretch water. 319 00:14:29,040 --> 00:14:31,000 Speaker 2: Yeah, exactly, to stretch water. 320 00:14:31,040 --> 00:14:32,760 Speaker 1: So like the parts of the the equator there are 321 00:14:32,840 --> 00:14:36,040 Speaker 1: closest to the Moon, the Earth is being squeezed and stretched, 322 00:14:36,080 --> 00:14:38,800 Speaker 1: but the water on the surface on that side is 323 00:14:38,840 --> 00:14:42,200 Speaker 1: getting stretched even more, and that's what causes the tides. 324 00:14:42,200 --> 00:14:45,000 Speaker 2: And that's what causes the tides. Not just the Moon though, 325 00:14:45,080 --> 00:14:47,720 Speaker 2: right the Sun also plays a role because there's tidal 326 00:14:47,800 --> 00:14:50,920 Speaker 2: forces from the Sun. The Sun also has gravity on 327 00:14:51,000 --> 00:14:53,240 Speaker 2: the Earth, and as the Earth moves around the Sun, 328 00:14:53,640 --> 00:14:56,840 Speaker 2: different parts of the Earth feel gravity differently from the 329 00:14:56,920 --> 00:14:59,160 Speaker 2: Sun because there are different distances from the Sun. 330 00:15:00,040 --> 00:15:02,280 Speaker 1: Says maybe as a kid, I thought that maybe I 331 00:15:02,320 --> 00:15:04,880 Speaker 1: knew that the tides were caused by the Moon, but 332 00:15:05,000 --> 00:15:06,880 Speaker 1: I thought maybe it was like it was pulling the water. 333 00:15:07,040 --> 00:15:09,360 Speaker 1: And so it's basically like sucking all the water to 334 00:15:09,480 --> 00:15:12,000 Speaker 1: one side of the Earth, like it's bringing water from 335 00:15:12,040 --> 00:15:13,920 Speaker 1: the far side of the Earth to the near side 336 00:15:13,920 --> 00:15:15,480 Speaker 1: of the Earth facing the Moon. 337 00:15:15,640 --> 00:15:17,720 Speaker 2: It is doing that, but on the other side, it's 338 00:15:17,800 --> 00:15:20,520 Speaker 2: also sort of pulling the Earth harder than it's pulling 339 00:15:20,560 --> 00:15:23,440 Speaker 2: the water, and so it's leaving some of the water behind, 340 00:15:23,640 --> 00:15:25,560 Speaker 2: so you get deeper water on the spot closest to 341 00:15:25,640 --> 00:15:28,120 Speaker 2: the Moon and on the other side as well. 342 00:15:28,680 --> 00:15:31,160 Speaker 1: Whoa wait, wait, wait, but I thought the water was 343 00:15:31,240 --> 00:15:31,960 Speaker 1: more squishable. 344 00:15:32,200 --> 00:15:35,000 Speaker 2: Water is more squishable, so it responds more quickly to 345 00:15:35,120 --> 00:15:37,760 Speaker 2: these tidal forces. So the tidle forces on the spot 346 00:15:37,840 --> 00:15:40,480 Speaker 2: closest to the Moon are pulling it towards the Moon, 347 00:15:40,920 --> 00:15:43,840 Speaker 2: making that water deeper. The tidal forces on the spot 348 00:15:43,880 --> 00:15:47,040 Speaker 2: opposite side are pushing things away from the center of 349 00:15:47,120 --> 00:15:49,760 Speaker 2: the Earth, and so that's sort of pushing that water 350 00:15:49,960 --> 00:15:52,480 Speaker 2: up and then around the circumference it's squeezing it. So 351 00:15:52,600 --> 00:15:55,240 Speaker 2: squeezes that water and pushes it towards the sort of 352 00:15:55,560 --> 00:15:56,600 Speaker 2: cones of the football. 353 00:15:56,920 --> 00:15:59,080 Speaker 1: Mmmm. And so like if you look at a tide 354 00:15:59,080 --> 00:16:02,080 Speaker 1: schedule for a bee, which you're seeing like the dynamics 355 00:16:02,120 --> 00:16:04,560 Speaker 1: of the Moon and the Sun and the effects they 356 00:16:04,600 --> 00:16:07,040 Speaker 1: have on the Earth. Yeah, exactly, It's like this dance 357 00:16:07,120 --> 00:16:10,400 Speaker 1: between all three things is what causes those weird tidal charts. 358 00:16:10,520 --> 00:16:12,600 Speaker 2: Yeah, the dance between those three things is part of 359 00:16:12,680 --> 00:16:15,400 Speaker 2: the explanation. The Moon dominates. Of course, the Sun is 360 00:16:15,520 --> 00:16:18,600 Speaker 2: much more massive and has more gravity, but we're much 361 00:16:18,720 --> 00:16:21,800 Speaker 2: further from the Sun, and on balance, the Moon's tidal 362 00:16:21,840 --> 00:16:25,520 Speaker 2: forces are like two times as powerful as the Sun's. Overall, 363 00:16:25,600 --> 00:16:28,080 Speaker 2: this is a pretty tiny effect relative to Earth's gravity. 364 00:16:28,120 --> 00:16:31,320 Speaker 2: It's like one part per million or less variation in 365 00:16:31,400 --> 00:16:34,840 Speaker 2: the Earth's gravity, but it can cause big effects. Like 366 00:16:34,920 --> 00:16:38,600 Speaker 2: there's places in Canada where there's a sixteen meter difference 367 00:16:38,640 --> 00:16:40,520 Speaker 2: between the low tide and the high tide. 368 00:16:40,680 --> 00:16:44,640 Speaker 1: Whoa wait, sixteen meter difference in the height of the water, 369 00:16:45,280 --> 00:16:47,400 Speaker 1: or like the shoreline in the height of the water. 370 00:16:47,520 --> 00:16:50,480 Speaker 1: Oh wow, why is it more there than in other places? 371 00:16:50,720 --> 00:16:52,680 Speaker 2: So there's a bunch of different things going on. Number 372 00:16:52,720 --> 00:16:54,800 Speaker 2: one is it's not just the simple model of the 373 00:16:54,840 --> 00:16:57,160 Speaker 2: Earth and the Moon. Also, the Moon is sort of 374 00:16:57,240 --> 00:17:00,800 Speaker 2: declined relative to the Earth. It's not actually orbiting around 375 00:17:00,840 --> 00:17:03,720 Speaker 2: the equator, which means that like sometimes it's closer to 376 00:17:03,760 --> 00:17:06,840 Speaker 2: the northern hemisphere and sometimes it's closer to the southern hemisphere. 377 00:17:07,040 --> 00:17:09,840 Speaker 2: So you get this cycle they call a fortnightly cycle 378 00:17:10,320 --> 00:17:13,320 Speaker 2: fortnite meeting every two weeks, because the Moon's orbit is 379 00:17:13,320 --> 00:17:16,640 Speaker 2: about a month obviously, and so every two weeks you're 380 00:17:16,680 --> 00:17:18,480 Speaker 2: in one half of the cycle and every two weeks 381 00:17:18,560 --> 00:17:20,680 Speaker 2: you're in the other half of the cycle. So there's 382 00:17:20,720 --> 00:17:23,560 Speaker 2: lots of these little effects that are all gravitational that 383 00:17:23,720 --> 00:17:26,639 Speaker 2: tug on the water differently. And then there's the response 384 00:17:26,760 --> 00:17:28,800 Speaker 2: of the water. So it depends on like the shape 385 00:17:28,840 --> 00:17:31,399 Speaker 2: or the harbor and how the deep ocean tides are 386 00:17:31,440 --> 00:17:34,320 Speaker 2: affected and all sorts of like resonance effects in the 387 00:17:34,440 --> 00:17:36,520 Speaker 2: water because you're pulling on the water, but it's not 388 00:17:36,600 --> 00:17:40,840 Speaker 2: responding instantaneously that it's sloshing around, So which is why 389 00:17:40,880 --> 00:17:42,600 Speaker 2: you get different tides in different places. 390 00:17:42,880 --> 00:17:46,119 Speaker 1: Right, Like I think in the Caribbean Ocean the tide 391 00:17:46,320 --> 00:17:49,439 Speaker 1: changes are much less than in the Pacific Ocean, for example. 392 00:17:49,520 --> 00:17:52,480 Speaker 2: Mm hmm, yeah, exactly. So it depends on the depth 393 00:17:52,520 --> 00:17:54,440 Speaker 2: of the water, depends on the shape of the shore, 394 00:17:54,960 --> 00:17:57,960 Speaker 2: it depends on how the water is flowing. It's very complicated, 395 00:17:58,160 --> 00:18:00,320 Speaker 2: and actually out there in the deep ocean, we don't 396 00:18:00,359 --> 00:18:02,720 Speaker 2: know very much about the effective tides and the depths 397 00:18:02,760 --> 00:18:05,280 Speaker 2: of them. We've measured them on the shore because they're 398 00:18:05,359 --> 00:18:08,080 Speaker 2: very important for boats coming in and boats leaving, but 399 00:18:08,160 --> 00:18:10,120 Speaker 2: out there in the deep ocean it's much murkier. 400 00:18:10,320 --> 00:18:12,600 Speaker 1: Well, I wonder if it's a bigger effect, Like the 401 00:18:12,640 --> 00:18:15,719 Speaker 1: deeper the ocean is, the more it's going to basically 402 00:18:15,800 --> 00:18:17,840 Speaker 1: get stretched by the moon. So like maybe in the 403 00:18:17,880 --> 00:18:20,480 Speaker 1: middle of the ocean, the height of the ocean is 404 00:18:20,920 --> 00:18:21,600 Speaker 1: changing a lot. 405 00:18:21,840 --> 00:18:24,280 Speaker 2: Yeah, exactly. We just have fewer sensors out there and 406 00:18:24,359 --> 00:18:26,920 Speaker 2: fewer like immediate reasons to know. We're curious from a 407 00:18:26,960 --> 00:18:30,439 Speaker 2: sort of like geological perspective, you know, for people who 408 00:18:30,520 --> 00:18:33,280 Speaker 2: really want to understand the tides, but it's not as 409 00:18:33,320 --> 00:18:36,199 Speaker 2: important for understanding like when your tunic crawler is going 410 00:18:36,240 --> 00:18:36,680 Speaker 2: to come back. 411 00:18:36,840 --> 00:18:39,840 Speaker 1: All right, well, let's dig into what land tides are 412 00:18:40,000 --> 00:18:43,000 Speaker 1: now and how those affect the shape of the Earth 413 00:18:43,400 --> 00:18:46,400 Speaker 1: and maybe how these forces can also affect our whole galaxy. 414 00:18:47,359 --> 00:18:49,720 Speaker 1: So let's dig into that. But first let's take a 415 00:18:49,800 --> 00:19:04,720 Speaker 1: quick break. All right, we're talking about tides now, Daniel, 416 00:19:04,720 --> 00:19:07,359 Speaker 1: what's the history of tides and our understanding of them. 417 00:19:07,680 --> 00:19:10,600 Speaker 2: Yeah, we've known about tides forever, right, as long as 418 00:19:10,680 --> 00:19:13,679 Speaker 2: we've known about lightning and rain and all sorts of stuff, 419 00:19:13,800 --> 00:19:16,240 Speaker 2: and people have been wondering for a long time about 420 00:19:16,280 --> 00:19:18,200 Speaker 2: the cause of it and trying to understand it. And 421 00:19:18,280 --> 00:19:21,040 Speaker 2: it's obviously connected to the moon, right, the cycles of 422 00:19:21,119 --> 00:19:24,640 Speaker 2: the moon are connected to the tides, and so as 423 00:19:24,720 --> 00:19:26,840 Speaker 2: far back as the Greeks, we have records of people 424 00:19:26,880 --> 00:19:31,119 Speaker 2: speculating that somehow the moon caused it. The Greeks had 425 00:19:31,119 --> 00:19:33,920 Speaker 2: no understanding of gravity as we do, of course, so 426 00:19:34,000 --> 00:19:37,359 Speaker 2: they definitely didn't understand tidal forces and couldn't put together 427 00:19:37,480 --> 00:19:38,800 Speaker 2: like a mechanistic explanation. 428 00:19:39,000 --> 00:19:40,920 Speaker 1: But somehow they knew is related to the moon. 429 00:19:41,240 --> 00:19:43,959 Speaker 2: They suspected it was related to the moon, just because 430 00:19:44,000 --> 00:19:46,720 Speaker 2: it's linked to lunar cycles, right, is it? 431 00:19:46,840 --> 00:19:48,879 Speaker 1: I don't know, like it the tide goes up and 432 00:19:49,320 --> 00:19:52,439 Speaker 1: down twice a day, I think for most beaches, at 433 00:19:52,520 --> 00:19:54,399 Speaker 1: least in California, But I don't see the moon go 434 00:19:54,560 --> 00:19:55,879 Speaker 1: up and down twice a day. 435 00:19:56,000 --> 00:19:58,080 Speaker 2: I think if you keep close track of where the 436 00:19:58,200 --> 00:20:00,359 Speaker 2: Moon and the Sun and the Earth are, and the 437 00:20:00,400 --> 00:20:02,760 Speaker 2: Greeks definitely did this, and we have also evidence of 438 00:20:02,840 --> 00:20:06,200 Speaker 2: Islamic astronomers doing this. You notice the connection between where 439 00:20:06,320 --> 00:20:09,080 Speaker 2: the moon is and where the tides are, right, because 440 00:20:09,119 --> 00:20:11,800 Speaker 2: remember it's the location of the moon that's dictating. It's 441 00:20:11,840 --> 00:20:13,680 Speaker 2: where the moon is closest to the Earth is where 442 00:20:13,760 --> 00:20:15,440 Speaker 2: there are going to be high tides, and then also 443 00:20:15,840 --> 00:20:17,920 Speaker 2: on the other side of it. So the location of 444 00:20:17,920 --> 00:20:20,240 Speaker 2: the Moon is definitely connected to the height of the tides. 445 00:20:20,560 --> 00:20:23,359 Speaker 2: You don't need to know gravity just to see this connection. 446 00:20:24,040 --> 00:20:26,560 Speaker 1: But is our wonder if there's a delay, like do 447 00:20:26,560 --> 00:20:29,000 Speaker 1: you see a delay between when the moon is closest 448 00:20:29,040 --> 00:20:31,199 Speaker 1: to the Earth and when the tides are highest. 449 00:20:31,400 --> 00:20:34,720 Speaker 2: There's definitely a delay, right, because water doesn't respond instantaneously 450 00:20:34,800 --> 00:20:37,000 Speaker 2: and there are all these other effects. But people have 451 00:20:37,080 --> 00:20:40,399 Speaker 2: been debating what the actual mechanism was. Galileo, for example, 452 00:20:40,520 --> 00:20:43,240 Speaker 2: suggested that it just had to do with the sloshing 453 00:20:43,320 --> 00:20:45,920 Speaker 2: of water as the Earth moon around the Sun. He 454 00:20:46,000 --> 00:20:47,920 Speaker 2: thought that if you had an object covered in water 455 00:20:48,080 --> 00:20:50,280 Speaker 2: and it was orbiting the Sun, that the water was 456 00:20:50,320 --> 00:20:52,320 Speaker 2: going to slosh around it the way like a bucket 457 00:20:52,359 --> 00:20:53,560 Speaker 2: would slash as you walk with. 458 00:20:53,600 --> 00:20:56,040 Speaker 1: It, or whonderver. They thought like maybe there's a like 459 00:20:56,119 --> 00:20:59,000 Speaker 1: a giant tick in a bath in the ocean, Like 460 00:20:59,080 --> 00:21:01,560 Speaker 1: did they think maybe, you know, like the archimittees of fact, 461 00:21:01,640 --> 00:21:05,280 Speaker 1: like if you get an ocean the water rises, Did 462 00:21:05,359 --> 00:21:07,200 Speaker 1: they think maybe it was related to something. 463 00:21:07,000 --> 00:21:09,520 Speaker 2: Like that, that'd be a very regular giant. Yeah. The 464 00:21:09,560 --> 00:21:12,480 Speaker 2: Greeks probably did have some mythology related to the tides. 465 00:21:12,520 --> 00:21:15,359 Speaker 2: Poseidon probably controlled them. I'm not an expert in that, 466 00:21:16,119 --> 00:21:18,760 Speaker 2: but the first real explanation for the tides in terms 467 00:21:18,760 --> 00:21:21,639 Speaker 2: of a mechanism comes of course from Isaac Newton in 468 00:21:21,760 --> 00:21:24,639 Speaker 2: his groundbreaking where Principia, where he lays out the theory 469 00:21:24,680 --> 00:21:27,520 Speaker 2: of gravity. He's also at the same time able to 470 00:21:27,680 --> 00:21:31,080 Speaker 2: explain the tides and why the tides happen twice a 471 00:21:31,200 --> 00:21:33,840 Speaker 2: day because the water piles up at the spot closest 472 00:21:33,880 --> 00:21:36,080 Speaker 2: to the moon and the spot furthest. 473 00:21:35,960 --> 00:21:38,360 Speaker 1: Interesting because the Moon goes around the Earth once a day, 474 00:21:38,720 --> 00:21:40,920 Speaker 1: or I guess technically the Earth spins once a day. 475 00:21:41,680 --> 00:21:43,880 Speaker 2: Yeah, the motion of the Moon relative to the Earth 476 00:21:44,000 --> 00:21:46,080 Speaker 2: is roughly once per day. Yeah, that's what a day 477 00:21:46,400 --> 00:21:46,720 Speaker 2: is really. 478 00:21:46,840 --> 00:21:48,600 Speaker 1: And then later, I guess we got fancier with the 479 00:21:48,640 --> 00:21:51,400 Speaker 1: models of this and we're able to predict more accurately 480 00:21:51,480 --> 00:21:52,520 Speaker 1: what the tides are going to be. 481 00:21:53,119 --> 00:21:56,879 Speaker 2: Yeah, exactly. Newton's calculations allow you to predict the forcing, 482 00:21:56,960 --> 00:21:59,200 Speaker 2: like how much force there is from the Moon on 483 00:21:59,320 --> 00:22:02,280 Speaker 2: the water, but the actual motion of the water requires 484 00:22:02,320 --> 00:22:05,520 Speaker 2: you to understand fluid dynamics and ocean depth and take 485 00:22:05,520 --> 00:22:07,879 Speaker 2: ato account like the Earth's rotation and the shape of 486 00:22:07,920 --> 00:22:10,400 Speaker 2: the coast, and so Over the last few hundred years 487 00:22:10,440 --> 00:22:13,159 Speaker 2: people have added all that understanding to a model of 488 00:22:13,240 --> 00:22:15,720 Speaker 2: the tides, and now we can predict the tides like 489 00:22:15,960 --> 00:22:18,879 Speaker 2: years in advance at any point on the coast. 490 00:22:19,280 --> 00:22:21,560 Speaker 1: Wow, just from the position of the moon where we 491 00:22:21,720 --> 00:22:23,320 Speaker 1: know it's going to be in the future, and the. 492 00:22:23,359 --> 00:22:25,800 Speaker 2: Sun exactly, and the models of the ocean and the 493 00:22:25,880 --> 00:22:28,080 Speaker 2: Earth's rotation taking all of this into account. 494 00:22:28,160 --> 00:22:30,639 Speaker 1: M all right, Well, let's get to the question of 495 00:22:30,680 --> 00:22:32,880 Speaker 1: the episode, which is what are land tides? 496 00:22:33,480 --> 00:22:33,640 Speaker 3: Now? 497 00:22:34,119 --> 00:22:36,320 Speaker 1: Daniel, I don't see the land going up and down 498 00:22:36,760 --> 00:22:40,800 Speaker 1: at the beach or anywhere, So what does this term mean? 499 00:22:41,000 --> 00:22:43,240 Speaker 2: So the term means exactly what you think. It means 500 00:22:43,320 --> 00:22:46,080 Speaker 2: that the Earth's land goes up and down the same 501 00:22:46,200 --> 00:22:49,600 Speaker 2: way that water in the ocean does. It's just that 502 00:22:49,680 --> 00:22:51,720 Speaker 2: the Earth doesn't respond the same way the ocean does 503 00:22:51,760 --> 00:22:53,640 Speaker 2: because the Earth is not made of water. 504 00:22:54,080 --> 00:22:56,240 Speaker 1: All right, So what do you mean by the land tide? 505 00:22:56,480 --> 00:22:59,159 Speaker 1: Am I going to see this effect? Or am I 506 00:22:59,359 --> 00:23:01,920 Speaker 1: just gonna have to think about the idea that maybe 507 00:23:01,920 --> 00:23:04,120 Speaker 1: I'm further away from the center of the Earth sometimes 508 00:23:04,280 --> 00:23:05,280 Speaker 1: than other times. 509 00:23:05,320 --> 00:23:07,920 Speaker 2: It's not something you need to factor into your daily life. 510 00:23:08,200 --> 00:23:10,760 Speaker 2: It's not really gonna change your drive to work, or 511 00:23:11,040 --> 00:23:13,280 Speaker 2: even if you work on like a shrimp trawler or 512 00:23:13,400 --> 00:23:15,560 Speaker 2: any sort of ocean vessel. It's not really gonna affect you, 513 00:23:15,760 --> 00:23:17,440 Speaker 2: but it is cool, I think to understand that the 514 00:23:17,480 --> 00:23:20,359 Speaker 2: whole earth is being squeezed. The taidle forces don't just 515 00:23:20,480 --> 00:23:23,359 Speaker 2: affect the water. The earth is also there feeling them. 516 00:23:23,800 --> 00:23:27,040 Speaker 2: And the earth is not perfectly rigid. Right, Yes, it's 517 00:23:27,119 --> 00:23:30,040 Speaker 2: made of rock, which is definitely stiffer than the water, 518 00:23:30,520 --> 00:23:33,359 Speaker 2: but it's not perfectly rigid, and so it responds. 519 00:23:33,119 --> 00:23:36,320 Speaker 1: Meaning like you can technically squeeze and stretch rock. Right, 520 00:23:36,440 --> 00:23:39,080 Speaker 1: It won't stretch or squeeze a lot, but technically it's 521 00:23:39,160 --> 00:23:40,800 Speaker 1: gonna move a little bit, tiny bit. 522 00:23:40,960 --> 00:23:43,400 Speaker 2: Yeah, exactly, and it's not even a tiny little bit. 523 00:23:43,800 --> 00:23:46,160 Speaker 2: I was reading a calculation that says that New York 524 00:23:46,240 --> 00:23:49,720 Speaker 2: City rises by more than a foot as these land 525 00:23:49,800 --> 00:23:50,520 Speaker 2: tides progress. 526 00:23:50,920 --> 00:23:54,360 Speaker 1: Whoa, but relative to what I guess, yeah. 527 00:23:54,240 --> 00:23:56,920 Speaker 2: Relative to the center of the earth. So it's not 528 00:23:57,040 --> 00:23:59,440 Speaker 2: something you notice because it's not like one block in 529 00:23:59,520 --> 00:24:02,800 Speaker 2: Manhattan moves up a foot relative to another block. The 530 00:24:02,880 --> 00:24:05,960 Speaker 2: whole city moves together as the crust of the earth 531 00:24:06,080 --> 00:24:06,720 Speaker 2: is flexing. 532 00:24:08,080 --> 00:24:10,560 Speaker 1: Basically, you're sort of treating the earth like a bouncy ball, right, 533 00:24:11,000 --> 00:24:12,200 Speaker 1: or like one of those stress balls. 534 00:24:12,400 --> 00:24:14,320 Speaker 2: Yeah. And part of the history here is really cool 535 00:24:14,400 --> 00:24:16,560 Speaker 2: because it goes back to when people were trying to 536 00:24:16,560 --> 00:24:19,159 Speaker 2: figure out what is the Earth made out of? Like 537 00:24:19,440 --> 00:24:21,480 Speaker 2: is the Earth just a big ball of solid rock 538 00:24:21,880 --> 00:24:24,399 Speaker 2: or is it totally molten and fluid? Like is the 539 00:24:24,480 --> 00:24:27,960 Speaker 2: Earth a water balloon or is it a marble or 540 00:24:28,160 --> 00:24:30,120 Speaker 2: is it a bouncy ball? And so people were trying 541 00:24:30,119 --> 00:24:32,960 Speaker 2: to figure this out hundreds of years ago, before they 542 00:24:33,000 --> 00:24:35,080 Speaker 2: could like dig into the earth, or before we had 543 00:24:35,119 --> 00:24:38,200 Speaker 2: modern seismology that reveals what's going on inside of the 544 00:24:38,280 --> 00:24:40,800 Speaker 2: Earth by how earthquakes like bounce around on all the 545 00:24:40,880 --> 00:24:41,719 Speaker 2: internal layers. 546 00:24:41,840 --> 00:24:43,280 Speaker 1: You mean more like a lava balloon. 547 00:24:43,560 --> 00:24:47,200 Speaker 2: Yeah, a lava balloon exactly. In the late eighteen hundreds, 548 00:24:47,280 --> 00:24:50,320 Speaker 2: the prevailing theory of what was inside the Earth was 549 00:24:50,400 --> 00:24:53,199 Speaker 2: that it was molten. Right, people saw lava, and oh, well, 550 00:24:53,280 --> 00:24:56,359 Speaker 2: maybe the Earth is just filled with lava, right, maybe 551 00:24:56,400 --> 00:24:59,560 Speaker 2: it's fluid. So then scientists try to calculate like, all right, 552 00:24:59,640 --> 00:25:02,200 Speaker 2: well then, and what should be the earth tides? If 553 00:25:02,280 --> 00:25:05,800 Speaker 2: the Earth is just a balloon filled with lava, then 554 00:25:05,920 --> 00:25:09,760 Speaker 2: Lord Kelvin actually calculated that we should have huge earth 555 00:25:09,840 --> 00:25:12,600 Speaker 2: tides because if the Earth is as flexible as the 556 00:25:12,720 --> 00:25:15,240 Speaker 2: ocean is. Right, if it's just basically an ocean of 557 00:25:15,359 --> 00:25:18,640 Speaker 2: lava underneath a thin crust, then we should be seeing 558 00:25:18,880 --> 00:25:21,560 Speaker 2: huge tides as big as we see in the ocean. 559 00:25:21,640 --> 00:25:24,920 Speaker 1: But would lava be as quishable as water, Isn't it 560 00:25:25,080 --> 00:25:26,639 Speaker 1: the thicker and more denser. 561 00:25:26,920 --> 00:25:29,480 Speaker 2: Yeah, it's definitely thicker and denser. So it's not exactly 562 00:25:29,640 --> 00:25:32,000 Speaker 2: like water. But if you take all that into account, 563 00:25:32,040 --> 00:25:35,280 Speaker 2: you predict huge earth tides, you predict that the land 564 00:25:35,400 --> 00:25:38,080 Speaker 2: was should change by meters and meters, and we definitely 565 00:25:38,119 --> 00:25:41,000 Speaker 2: didn't see that. And so that's one very early sign 566 00:25:41,040 --> 00:25:44,440 Speaker 2: they had that the earth is more rigid than water internally. 567 00:25:44,760 --> 00:25:46,840 Speaker 2: It's just like a way to see what's inside the 568 00:25:46,920 --> 00:25:48,800 Speaker 2: earth without even looking inside. 569 00:25:49,320 --> 00:25:51,040 Speaker 1: So if the earth was made out of all a 570 00:25:51,160 --> 00:25:53,879 Speaker 1: lava inside, we would we would basically see New York 571 00:25:53,920 --> 00:25:56,359 Speaker 1: City rise and fall by a lot more than a 572 00:25:56,400 --> 00:26:00,040 Speaker 1: food Yeah, exactly would Like would you would you? I 573 00:26:00,040 --> 00:26:02,199 Speaker 1: guess you would see it as a wave, like New 574 00:26:02,320 --> 00:26:04,840 Speaker 1: York City would rise a bunch and then go down, 575 00:26:04,920 --> 00:26:09,040 Speaker 1: and then you know New Jersey or Pennsylvania would then 576 00:26:09,160 --> 00:26:11,000 Speaker 1: rise and fall, right, that's kind of the idea. 577 00:26:11,160 --> 00:26:13,359 Speaker 2: Yeah, And you would have much more dramatic like earthquakes, 578 00:26:13,680 --> 00:26:16,080 Speaker 2: because land tides can cause a lot of pressure on 579 00:26:16,200 --> 00:26:19,639 Speaker 2: the boundaries between the plates and cause all sorts of earthquakes, 580 00:26:20,040 --> 00:26:22,440 Speaker 2: So it would make life on Earth much more dramatic. 581 00:26:23,640 --> 00:26:27,280 Speaker 1: But thankfully we're not a giant love of ball. We're 582 00:26:27,720 --> 00:26:31,280 Speaker 1: fairly rigid. We're mostly rock up until the core of 583 00:26:31,320 --> 00:26:33,200 Speaker 1: the earth, right or the inner mantle. 584 00:26:33,440 --> 00:26:35,800 Speaker 2: Yeah, it's quite dense, but it is actually pretty fluid. 585 00:26:36,000 --> 00:26:38,440 Speaker 2: But the outer edge is pretty hard and definitely much 586 00:26:38,600 --> 00:26:42,200 Speaker 2: less fluid than water. So original calculations by Lord Kelvin, 587 00:26:42,320 --> 00:26:44,919 Speaker 2: the fact that he couldn't see any earth tides himself, 588 00:26:45,480 --> 00:26:48,119 Speaker 2: basically let him estimate that the internal part of the 589 00:26:48,200 --> 00:26:52,679 Speaker 2: Earth was more rigid than glass, but less rigid than 590 00:26:52,800 --> 00:26:56,720 Speaker 2: iron for example, so very very rough. And then around 591 00:26:56,760 --> 00:26:59,439 Speaker 2: one hundred years ago people started trying to actually measure 592 00:26:59,480 --> 00:27:02,880 Speaker 2: this thing. So people built these tilt meters to try 593 00:27:02,880 --> 00:27:06,160 Speaker 2: to see, like, can you tell if the Earth is tilting, 594 00:27:06,800 --> 00:27:09,480 Speaker 2: Like if you have essentially a bathtub filled with water, 595 00:27:09,720 --> 00:27:11,880 Speaker 2: then the surface of the water tells you like where 596 00:27:11,960 --> 00:27:14,680 Speaker 2: gravity is all equal, and then if the surface of 597 00:27:14,760 --> 00:27:17,840 Speaker 2: the Earth tilts on which the bathtub is sitting, right, 598 00:27:17,920 --> 00:27:20,640 Speaker 2: there's like a wave that passes through the ground, it'll 599 00:27:20,680 --> 00:27:23,320 Speaker 2: tilt the bathtub and you'll see waves in the bathtub. 600 00:27:24,119 --> 00:27:27,160 Speaker 2: So people were using these like long tubes of water 601 00:27:27,400 --> 00:27:29,720 Speaker 2: looking for waves in them to see if they could 602 00:27:29,760 --> 00:27:33,560 Speaker 2: measure the earth tilting, looking basically for waves in the ground. 603 00:27:33,720 --> 00:27:35,520 Speaker 1: Interesting, So, like if you wanted to see New York 604 00:27:35,560 --> 00:27:37,639 Speaker 1: City when up a foot or not or more than 605 00:27:37,680 --> 00:27:40,640 Speaker 1: a foot, you would maybe put one of these tiltmeters 606 00:27:40,800 --> 00:27:43,360 Speaker 1: on the outskirts of New York City, so that when 607 00:27:43,440 --> 00:27:45,560 Speaker 1: New York City goes up, this thing would tilt and 608 00:27:45,560 --> 00:27:47,359 Speaker 1: would tell you, hey, new York City went up. 609 00:27:47,600 --> 00:27:50,880 Speaker 2: Yeah, exactly. These days, you can measure land ties most 610 00:27:50,960 --> 00:27:56,159 Speaker 2: precisely with gravitometers. Things are basically accelerometers. You can measure 611 00:27:56,240 --> 00:27:59,639 Speaker 2: the strength of gravity because you're measuring the acceleration of 612 00:27:59,720 --> 00:28:02,479 Speaker 2: the Earth Earth pushing up on you to overcome your 613 00:28:02,600 --> 00:28:06,919 Speaker 2: natural freefall. So essentially every accelerometer really is a gravitometer. 614 00:28:07,280 --> 00:28:09,240 Speaker 2: So the way they measure land tides now is they 615 00:28:09,320 --> 00:28:12,320 Speaker 2: measure how the gravity is varying, because as you get 616 00:28:12,359 --> 00:28:15,640 Speaker 2: further from the center of the Earth, your gravity decreases. 617 00:28:15,480 --> 00:28:17,680 Speaker 1: But doesn't the moon effect that gravity. 618 00:28:17,240 --> 00:28:20,359 Speaker 2: As well, it absolutely does. Yeah, So what you're measuring 619 00:28:20,520 --> 00:28:23,240 Speaker 2: is you decrease on your gravity from being further or 620 00:28:23,359 --> 00:28:25,360 Speaker 2: closer to the center of the Earth. And you're also 621 00:28:25,400 --> 00:28:28,000 Speaker 2: measuring the Moon pulling on you directly and the sun. 622 00:28:28,440 --> 00:28:30,800 Speaker 2: So you got to disentangle all of this stuff to 623 00:28:30,880 --> 00:28:33,320 Speaker 2: get the land tide effect out. But that's how they 624 00:28:33,359 --> 00:28:34,480 Speaker 2: measure it most precisely. 625 00:28:34,560 --> 00:28:34,679 Speaker 3: Now. 626 00:28:35,080 --> 00:28:37,240 Speaker 1: So like you're saying, like, my weight here on Earth 627 00:28:37,720 --> 00:28:40,600 Speaker 1: varies depending on where the moon is, not on what 628 00:28:40,680 --> 00:28:43,440 Speaker 1: I had for lunch. Yeah, all of those things. 629 00:28:44,240 --> 00:28:47,880 Speaker 2: All of those things absolutely. Yeah, the moon is pulling 630 00:28:47,960 --> 00:28:50,120 Speaker 2: on you differently based on where it is, so it's 631 00:28:50,160 --> 00:28:52,920 Speaker 2: like the tidal force on a joorghe directly. But then 632 00:28:53,080 --> 00:28:56,000 Speaker 2: also the Moon is changing the shape of the Earth, 633 00:28:56,040 --> 00:28:58,520 Speaker 2: which changes your distance from the center of the Earth, 634 00:28:58,720 --> 00:29:01,720 Speaker 2: which changes the earth gravity on you. And at the 635 00:29:01,760 --> 00:29:04,120 Speaker 2: same time, the Moon is pulling on the oceans, which 636 00:29:04,200 --> 00:29:06,680 Speaker 2: makes some of the oceans deeper or less deep, and 637 00:29:06,840 --> 00:29:09,560 Speaker 2: that also has an effect on the shape of the Earth. Right, 638 00:29:09,600 --> 00:29:13,200 Speaker 2: there's this like ocean pressure, this irregular loading on the 639 00:29:13,320 --> 00:29:16,479 Speaker 2: Earth also affects the shape of the Earth. And then 640 00:29:16,600 --> 00:29:19,200 Speaker 2: back and forth because as Earth itself gets squeezed by 641 00:29:19,240 --> 00:29:22,360 Speaker 2: the moon that affects the ocean tides, So a whole 642 00:29:22,400 --> 00:29:24,920 Speaker 2: thing is coupled in a really complicated way. Yeah, it 643 00:29:24,960 --> 00:29:27,200 Speaker 2: seems complicated. So then if you measure just the gravity, 644 00:29:27,200 --> 00:29:29,040 Speaker 2: how do you know what's doing what? You have to 645 00:29:29,080 --> 00:29:30,520 Speaker 2: have a model of all these things, and then you 646 00:29:30,560 --> 00:29:33,320 Speaker 2: can disentangle the various pieces as you measure how it 647 00:29:33,480 --> 00:29:34,400 Speaker 2: changes over time. 648 00:29:35,560 --> 00:29:38,320 Speaker 1: So then if the moon is directly over me, then 649 00:29:38,360 --> 00:29:39,920 Speaker 1: I'm going to weigh a little bit less? Am I 650 00:29:40,000 --> 00:29:41,680 Speaker 1: going to be able to feel that? Like, what's the 651 00:29:41,720 --> 00:29:42,840 Speaker 1: effect of the moon on me? 652 00:29:43,240 --> 00:29:45,720 Speaker 2: You could measure it if you had a very sensitive gravitometer. 653 00:29:46,120 --> 00:29:48,760 Speaker 2: The size the effect relative to the acceleration due to 654 00:29:48,840 --> 00:29:51,680 Speaker 2: Earth's gravity again is like one part in a million 655 00:29:51,800 --> 00:29:53,920 Speaker 2: or one part in ten million, So you need a 656 00:29:53,960 --> 00:29:56,360 Speaker 2: pretty precise gravitometer to detect this effect. 657 00:29:57,520 --> 00:29:59,480 Speaker 1: Well, I wonder you know, there's so much of biology 658 00:29:59,520 --> 00:30:02,280 Speaker 1: on Earth that is tied to the moon cycle, or 659 00:30:02,600 --> 00:30:05,680 Speaker 1: at least sort of tied to the moon cycle. Do 660 00:30:05,720 --> 00:30:07,960 Speaker 1: you think all of this biology is measuring the gravity 661 00:30:08,000 --> 00:30:10,160 Speaker 1: somehow or is it just going by moonlight? 662 00:30:10,240 --> 00:30:12,120 Speaker 2: I think you're absolutely right that a lot of biology 663 00:30:12,240 --> 00:30:14,400 Speaker 2: is tied to the tidal cycle and the cycles of 664 00:30:14,480 --> 00:30:17,080 Speaker 2: the moon. But I think that's because the local effects, 665 00:30:17,360 --> 00:30:19,240 Speaker 2: you know, the tide going up, the tide going down, 666 00:30:19,360 --> 00:30:22,160 Speaker 2: or there being more moonlight or less moonlight. I think 667 00:30:22,200 --> 00:30:24,800 Speaker 2: all these things are dependent on those secondary effects, not 668 00:30:25,000 --> 00:30:27,760 Speaker 2: directly on the gravity. But hey, I could be wrong. 669 00:30:28,080 --> 00:30:31,479 Speaker 2: You know, we recently discovered that birds have little quantum 670 00:30:31,520 --> 00:30:34,680 Speaker 2: mechanical sensors in their eyeballs that detect the magnetic field 671 00:30:34,720 --> 00:30:37,760 Speaker 2: of the Earth and help them navigate. So biology continues 672 00:30:37,840 --> 00:30:38,520 Speaker 2: to surprise us. 673 00:30:38,680 --> 00:30:41,800 Speaker 1: Yeah, we might have sensors within us that can detect 674 00:30:41,920 --> 00:30:45,080 Speaker 1: a millionth of a grammar or something of gravity changes. 675 00:30:45,600 --> 00:30:47,640 Speaker 2: Biology is amazing. I'll never understand it. 676 00:30:47,920 --> 00:30:50,480 Speaker 1: All right, well, those are land tides. Now let's get 677 00:30:50,560 --> 00:30:55,000 Speaker 1: into even bigger tides, bigger waves. Let's talk about galactic 678 00:30:55,120 --> 00:30:58,920 Speaker 1: tides what that means about our search for other planets. 679 00:30:59,000 --> 00:31:13,320 Speaker 1: But first, let's take an o quick break. All right, 680 00:31:13,320 --> 00:31:17,400 Speaker 1: we're talking about the tides, why they're high weather low, 681 00:31:18,920 --> 00:31:21,200 Speaker 1: And we talked about how the tides here on Earth 682 00:31:21,880 --> 00:31:24,080 Speaker 1: a fact, not just the oceans, but the Earth itself. 683 00:31:24,760 --> 00:31:27,480 Speaker 1: The Moon is squeezing all the rocks on Earth, changing 684 00:31:27,560 --> 00:31:29,480 Speaker 1: the shape of the Earth, making its rise and fall 685 00:31:30,320 --> 00:31:32,680 Speaker 1: and now Daniel, you're saying this also happens on a 686 00:31:32,800 --> 00:31:33,680 Speaker 1: galactic level. 687 00:31:34,120 --> 00:31:37,080 Speaker 2: Yeah, the motion of the Sun through the galaxy that 688 00:31:37,360 --> 00:31:41,280 Speaker 2: depends on gravity. It's being pulled by the gravitational center 689 00:31:41,480 --> 00:31:44,480 Speaker 2: of the galaxy, this huge black hole and all those stars. 690 00:31:44,960 --> 00:31:47,240 Speaker 2: It's also being pulled by lots of other stars. And 691 00:31:47,280 --> 00:31:50,600 Speaker 2: so the motion of the Sun through the galaxy is gravitational. 692 00:31:51,160 --> 00:31:54,959 Speaker 2: But our solar system itself is not a point object, right, 693 00:31:55,080 --> 00:31:58,000 Speaker 2: So the galaxy pulls differently on different parts of the 694 00:31:58,080 --> 00:32:00,440 Speaker 2: Solar system. The parts that are closer to the center 695 00:32:00,640 --> 00:32:03,640 Speaker 2: feel a stronger gravitational force than things that are further 696 00:32:03,720 --> 00:32:06,320 Speaker 2: from the center. And so the same way that like 697 00:32:06,440 --> 00:32:08,640 Speaker 2: the Moon is massaging the Earth, and of course the 698 00:32:08,720 --> 00:32:11,560 Speaker 2: Earth is massaging the Moon, and the Sun is massaging everybody, 699 00:32:12,000 --> 00:32:15,240 Speaker 2: the center of the galaxy is massaging our whole solar system. 700 00:32:15,360 --> 00:32:18,959 Speaker 1: WHOA, because I guess technically we're going around the galaxy 701 00:32:19,160 --> 00:32:22,000 Speaker 1: center sort of like the Earth is going around the Sun, 702 00:32:22,120 --> 00:32:26,080 Speaker 1: right exactly, Like we're trapped in the gravitational pol or 703 00:32:26,240 --> 00:32:28,280 Speaker 1: pull of everything in the galaxy, of. 704 00:32:28,360 --> 00:32:31,000 Speaker 2: Everything in the galaxy. Yeah, it takes about a quarter 705 00:32:31,120 --> 00:32:33,520 Speaker 2: of a billion years for the Sun to go all 706 00:32:33,600 --> 00:32:36,280 Speaker 2: the way around the galaxy, and it's like a thirty 707 00:32:36,360 --> 00:32:38,320 Speaker 2: million year cycle for it to go like above the 708 00:32:38,400 --> 00:32:40,840 Speaker 2: plane and below the plane. It's got this really funky 709 00:32:41,000 --> 00:32:43,160 Speaker 2: orbit around the center of the galaxy. But yeah, the 710 00:32:43,240 --> 00:32:46,560 Speaker 2: Sun is locked in gravitationally around the center of the galaxy, 711 00:32:47,080 --> 00:32:49,640 Speaker 2: and then gravity is massaging the Solar System. Remember the 712 00:32:49,680 --> 00:32:52,000 Speaker 2: Solar System is not just the Sun, right, it's also 713 00:32:52,080 --> 00:32:54,720 Speaker 2: the planets. So the Earth's or it gets tweaked a 714 00:32:54,880 --> 00:32:58,640 Speaker 2: little bit by this gravitational massage, which is one reason 715 00:32:58,680 --> 00:33:01,040 Speaker 2: we talked about, like the stability of the Earth's orbit 716 00:33:01,200 --> 00:33:03,920 Speaker 2: is important because there's all sorts of things like perturbing 717 00:33:04,000 --> 00:33:06,640 Speaker 2: it slightly. But on the outside of the Solar System 718 00:33:06,800 --> 00:33:10,240 Speaker 2: is this huge cluster of icy rocks called the ort cloud, 719 00:33:10,560 --> 00:33:14,040 Speaker 2: billions or maybe trillions of blocks of ice, which we 720 00:33:14,120 --> 00:33:17,520 Speaker 2: think are probably the source of long period comets. Commets 721 00:33:17,520 --> 00:33:21,440 Speaker 2: with periods like hundreds of years. The galaxies squeezing them 722 00:33:21,520 --> 00:33:23,520 Speaker 2: can perturb them, so they might be like in a 723 00:33:23,560 --> 00:33:26,200 Speaker 2: stable orbit around the Sun, but then they get pushed 724 00:33:26,240 --> 00:33:28,120 Speaker 2: to tying the little bit and they get tugged on 725 00:33:28,200 --> 00:33:30,800 Speaker 2: by other stuff and boom, now they're falling in towards 726 00:33:30,880 --> 00:33:32,240 Speaker 2: the center of the Solar system. 727 00:33:32,440 --> 00:33:35,200 Speaker 1: M I guess what you mean is like as the 728 00:33:35,280 --> 00:33:38,440 Speaker 1: Earth goes around the Sun in the Solar system, sometimes 729 00:33:38,520 --> 00:33:40,560 Speaker 1: it's closer to the center of the galaxy than it 730 00:33:40,720 --> 00:33:43,240 Speaker 1: is in other times in our orbit. And so that 731 00:33:43,320 --> 00:33:46,440 Speaker 1: you're saying the galaxies then is shaping our orbit here 732 00:33:46,760 --> 00:33:47,320 Speaker 1: of the Earth. 733 00:33:47,560 --> 00:33:49,880 Speaker 2: The galaxy definitely plays a role in the orbit of 734 00:33:49,920 --> 00:33:53,160 Speaker 2: the Earth and in its eccentricity. The Earth is pretty 735 00:33:53,240 --> 00:33:55,920 Speaker 2: stable in its orbit, as we talked about, but other 736 00:33:56,000 --> 00:33:58,479 Speaker 2: things are much less stable. They're lower mass, they're much 737 00:33:58,560 --> 00:34:01,800 Speaker 2: further from the Sun. It's unlikely that the galactic tides 738 00:34:01,840 --> 00:34:04,120 Speaker 2: are going to cause the Earth to plummet into the Sun. 739 00:34:04,680 --> 00:34:07,240 Speaker 2: Some little distant rock that's barely being held by the 740 00:34:07,320 --> 00:34:10,239 Speaker 2: Sun's gravity is much more likely to get its orbit 741 00:34:10,320 --> 00:34:13,279 Speaker 2: disturbed and then to fall in towards the center of 742 00:34:13,320 --> 00:34:14,000 Speaker 2: the Solar system. 743 00:34:14,880 --> 00:34:17,200 Speaker 1: Doesn't it depend on like the orientation of our Solar 744 00:34:17,280 --> 00:34:20,880 Speaker 1: system relative to the plane of the galaxy. Like at 745 00:34:20,920 --> 00:34:24,400 Speaker 1: the galaxy and our Solar system we're in the same plane, 746 00:34:24,760 --> 00:34:26,600 Speaker 1: then you would see a huge effect. Right, Like as 747 00:34:26,640 --> 00:34:28,440 Speaker 1: you go around the Sun, then sometimes you're really far 748 00:34:28,480 --> 00:34:30,920 Speaker 1: away from the galaxy the center of the galaxy. Sometimes 749 00:34:30,920 --> 00:34:34,040 Speaker 1: you're really closer. But let's say like our solar system 750 00:34:34,200 --> 00:34:38,000 Speaker 1: was more like a bicycle wheel going around the center 751 00:34:38,040 --> 00:34:40,400 Speaker 1: of the galaxy, then would it matter where in the 752 00:34:40,560 --> 00:34:42,720 Speaker 1: orbit you are, you would be almost the same distance 753 00:34:42,760 --> 00:34:43,680 Speaker 1: from the center of the galaxy. 754 00:34:43,800 --> 00:34:45,760 Speaker 2: Yeah, you're right. For things that orbit in the plane 755 00:34:45,840 --> 00:34:48,560 Speaker 2: of the Solar system, that is very important. And our 756 00:34:48,600 --> 00:34:51,440 Speaker 2: solar system is tilted relative to the plane of the galaxy. 757 00:34:51,680 --> 00:34:54,640 Speaker 2: How tilted, so there's like a sixty degree angle between 758 00:34:54,680 --> 00:34:57,960 Speaker 2: the plane and the galaxy and the planetary orbital plane, 759 00:34:58,560 --> 00:35:01,480 Speaker 2: so it's really quite tilted. It's not fully a bicycle wheel, 760 00:35:01,520 --> 00:35:03,840 Speaker 2: but there's like a sixty degree tilt there. But the 761 00:35:03,880 --> 00:35:06,400 Speaker 2: stuff in the orc cloud is not mostly in the 762 00:35:06,480 --> 00:35:08,480 Speaker 2: plane of the planets. The oor cloud is like a 763 00:35:08,520 --> 00:35:11,680 Speaker 2: sphere hasn't collapsed into a disk or into the plane, 764 00:35:12,200 --> 00:35:14,879 Speaker 2: and so that stuff is always feeling tidal forces. There's 765 00:35:14,880 --> 00:35:17,360 Speaker 2: always something closer to the center of the galaxy and 766 00:35:17,440 --> 00:35:19,520 Speaker 2: something further interesting. 767 00:35:19,680 --> 00:35:22,080 Speaker 1: So then and as you're saying, these rocks in these 768 00:35:22,400 --> 00:35:26,120 Speaker 1: asteroid belt are more sensitive because they're smaller, and so 769 00:35:26,640 --> 00:35:29,120 Speaker 1: then the galactic tidal forces can really make a difference. 770 00:35:29,160 --> 00:35:31,600 Speaker 2: There yeah, they're smaller, but also they're further from the 771 00:35:31,719 --> 00:35:34,480 Speaker 2: Sun and so the Sun just has less powerful hold 772 00:35:34,600 --> 00:35:37,680 Speaker 2: on them. And this is a big deal for life, right, 773 00:35:37,800 --> 00:35:40,240 Speaker 2: because commets plummeting towards the center of the Solar system 774 00:35:40,320 --> 00:35:44,399 Speaker 2: can be pretty deadly. One of them impacts Earth than boom, right, 775 00:35:44,600 --> 00:35:45,360 Speaker 2: mass extinction. 776 00:35:45,840 --> 00:35:48,719 Speaker 1: But also commets might bring water and things like that, Right, 777 00:35:49,160 --> 00:35:50,759 Speaker 1: those might be important then for life. 778 00:35:51,120 --> 00:35:53,880 Speaker 2: That's exactly right. We think that huge fraction of our 779 00:35:53,960 --> 00:35:57,400 Speaker 2: oceans may come from commets doing just that. So in 780 00:35:57,520 --> 00:36:00,239 Speaker 2: terms of like life evolving, you want a bunch of 781 00:36:00,280 --> 00:36:03,959 Speaker 2: galactic tides squeezing your work cloud so that you rain 782 00:36:04,120 --> 00:36:08,520 Speaker 2: down frozen comets onto newly formed planets so they get 783 00:36:08,560 --> 00:36:11,080 Speaker 2: oceans and form life. But then you don't want a 784 00:36:11,120 --> 00:36:14,000 Speaker 2: whole lot later on while that life is being incubated 785 00:36:14,080 --> 00:36:15,040 Speaker 2: and it's still fragile. 786 00:36:16,160 --> 00:36:20,200 Speaker 1: Well, speaking of life, also, aren't tidal forces in other moons, 787 00:36:20,239 --> 00:36:22,520 Speaker 1: for example, around the moons of Jupiter. Don't those effect 788 00:36:22,640 --> 00:36:26,879 Speaker 1: like the temperature of those moons, which might affect whether 789 00:36:26,920 --> 00:36:27,600 Speaker 1: there's life or not. 790 00:36:28,080 --> 00:36:31,240 Speaker 2: Absolutely we think that some of the internals of moons 791 00:36:31,320 --> 00:36:35,320 Speaker 2: around Jupiter are warm precisely because of these tidal forces, 792 00:36:35,800 --> 00:36:39,600 Speaker 2: and you're squeezing the entire planet, which causes friction inside 793 00:36:39,640 --> 00:36:43,080 Speaker 2: of it. Because you're massaging, you're changing its shape. It's 794 00:36:43,120 --> 00:36:44,840 Speaker 2: not just like it becomes a football and now it 795 00:36:44,920 --> 00:36:47,360 Speaker 2: moves like a football, which part of it is the 796 00:36:47,440 --> 00:36:51,120 Speaker 2: cone of the football is changing. So you're constantly squeezing it. 797 00:36:51,200 --> 00:36:53,200 Speaker 2: It's like you take cold dough out of the fridge 798 00:36:53,520 --> 00:36:56,000 Speaker 2: and you need it. It warms up, right, you're applying 799 00:36:56,160 --> 00:36:57,520 Speaker 2: energy to it. Internal friction. 800 00:36:57,840 --> 00:37:00,160 Speaker 1: Yeah, like if you massage a ball of clay, it's 801 00:37:00,200 --> 00:37:01,160 Speaker 1: going to warm up eventually. 802 00:37:01,320 --> 00:37:04,640 Speaker 2: Exactly. So some of these moons are warm on the inside. 803 00:37:04,719 --> 00:37:07,680 Speaker 2: We think they have liquid water oceans underneath a frozen 804 00:37:07,760 --> 00:37:11,120 Speaker 2: crust because of tidal forces, not because of internal heat 805 00:37:11,239 --> 00:37:13,920 Speaker 2: like the Earth, but because of tidal forces. Could be 806 00:37:14,080 --> 00:37:17,719 Speaker 2: keeping those moons warm and providing a place for life 807 00:37:18,120 --> 00:37:20,600 Speaker 2: here in our solar system or in other solar systems 808 00:37:20,719 --> 00:37:21,360 Speaker 2: whoa so. 809 00:37:21,640 --> 00:37:23,799 Speaker 1: In for example like Europa, right, which is the moon 810 00:37:23,880 --> 00:37:27,440 Speaker 1: of Jupiter. If there's life down there, basically their only 811 00:37:27,600 --> 00:37:30,600 Speaker 1: source of energy might be the tidal forces of Jupiter. 812 00:37:30,760 --> 00:37:33,720 Speaker 2: Yeah, exactly, and those are moon tides, I guess you'd 813 00:37:33,760 --> 00:37:37,200 Speaker 2: call them. Not sure, you're squeezing the whole Moon, and 814 00:37:37,360 --> 00:37:40,239 Speaker 2: that's where the energy comes from. Basically, you're extracting it 815 00:37:40,360 --> 00:37:43,359 Speaker 2: from the gradient of gravity of Jupiter, right. 816 00:37:43,520 --> 00:37:46,680 Speaker 1: Yeah, and they wouldn't see the Sun from underneath those 817 00:37:46,760 --> 00:37:51,040 Speaker 1: oceans in the ISO, like basically, Jupiter gravitationally would be 818 00:37:51,160 --> 00:37:51,719 Speaker 1: like their Sun. 819 00:37:52,160 --> 00:37:52,359 Speaker 3: Yeah. 820 00:37:52,360 --> 00:37:54,239 Speaker 2: I was just thinking about whether they'd also be able 821 00:37:54,280 --> 00:37:57,359 Speaker 2: to detect the gravity of the Sun. Imagine your life 822 00:37:57,400 --> 00:37:59,839 Speaker 2: that's formed under that ocean. You've never seen the star, 823 00:38:00,440 --> 00:38:02,720 Speaker 2: but if you're very sensitive to gravity, you might detect 824 00:38:02,760 --> 00:38:05,920 Speaker 2: the presence of Jupiter, and you probably eventually would detect 825 00:38:05,920 --> 00:38:09,000 Speaker 2: the presence of the Sun as well, perturbing effectively the 826 00:38:09,040 --> 00:38:11,600 Speaker 2: gravity of Jupiter. That'd be much more difficult than it 827 00:38:11,719 --> 00:38:14,360 Speaker 2: is here on Earth because Jupiter's gravity would be stronger 828 00:38:14,640 --> 00:38:16,800 Speaker 2: and the Sun's gravity would be weaker, so it'd be 829 00:38:16,800 --> 00:38:18,799 Speaker 2: a much more subtle effect than the Sun's gravity here. 830 00:38:18,880 --> 00:38:22,200 Speaker 2: But eventually those underwater scientists would figure it out. 831 00:38:22,320 --> 00:38:24,520 Speaker 1: Interesting, you mean those fishieses. 832 00:38:26,960 --> 00:38:29,600 Speaker 2: And that would make them tastier because of that knowledge. 833 00:38:30,520 --> 00:38:32,759 Speaker 1: Now, wonder if your fish that studies the stars, are 834 00:38:32,800 --> 00:38:33,840 Speaker 1: you astrophisies? 835 00:38:35,560 --> 00:38:37,120 Speaker 2: I think I'm finishist with this. 836 00:38:39,040 --> 00:38:41,960 Speaker 1: I'm just fishing for ideas here, Daniel, It's. 837 00:38:41,840 --> 00:38:44,319 Speaker 2: True that tides may power life underneath the frozen crust 838 00:38:44,360 --> 00:38:46,960 Speaker 2: of a moon. It's also possible the tides had a 839 00:38:47,040 --> 00:38:49,320 Speaker 2: really important role in the development of life here on 840 00:38:49,480 --> 00:38:52,800 Speaker 2: Earth and the development of life on other exoplanets. 841 00:38:52,920 --> 00:38:55,759 Speaker 1: Yeah, because I think scientists think that the tides had 842 00:38:55,800 --> 00:38:58,360 Speaker 1: a lot to do with how life evolved here on Earth, right, 843 00:38:58,520 --> 00:39:01,400 Speaker 1: or at least maybe how life got out of the oceans. 844 00:39:01,520 --> 00:39:03,480 Speaker 2: I hear a lot of different ideas, and all of 845 00:39:03,520 --> 00:39:06,040 Speaker 2: it's very speculative, all the way back to like the 846 00:39:06,120 --> 00:39:10,120 Speaker 2: actual formation of life itself from non life. That the 847 00:39:10,280 --> 00:39:13,080 Speaker 2: tides and the sloshing of all that water at the 848 00:39:13,160 --> 00:39:16,640 Speaker 2: shore helps like mix together primitive molecules that can come 849 00:39:16,719 --> 00:39:21,280 Speaker 2: together to make DNA or RNA or whatever, self replicating molecule. 850 00:39:21,600 --> 00:39:25,600 Speaker 2: Basically that the turbulence itself there was crucial biochemically that 851 00:39:25,680 --> 00:39:28,399 Speaker 2: you know, if water was just like static and sitting there, 852 00:39:28,480 --> 00:39:31,440 Speaker 2: it would take much longer for self replicating processes to 853 00:39:31,480 --> 00:39:31,959 Speaker 2: get going. 854 00:39:32,239 --> 00:39:34,440 Speaker 1: Meaning like the moon and the tides are a way 855 00:39:34,520 --> 00:39:36,799 Speaker 1: to steer the ocean kind of in a way which 856 00:39:36,920 --> 00:39:38,800 Speaker 1: in which you maybe kind of need in order to 857 00:39:39,719 --> 00:39:42,200 Speaker 1: just get life going. Makes it makes the right chemical. 858 00:39:42,200 --> 00:39:43,839 Speaker 2: I mean, nobody likes to be called a pot stir 859 00:39:44,040 --> 00:39:46,239 Speaker 2: but yeah, the moon is basically stirring the pot down here. 860 00:39:46,320 --> 00:39:50,320 Speaker 2: The Yeah, there's lots of different speculations. It might just 861 00:39:50,400 --> 00:39:53,440 Speaker 2: be the tub stirring. Some people think that having the 862 00:39:53,600 --> 00:39:57,120 Speaker 2: tides is like a way to concentrate solutions. Like you 863 00:39:57,280 --> 00:40:00,160 Speaker 2: throw water up on hot rocks that were sitting in 864 00:40:00,239 --> 00:40:02,640 Speaker 2: the sun, and then the water evaporates and you like 865 00:40:02,719 --> 00:40:05,000 Speaker 2: have concentrated all your chemicals so you can get like 866 00:40:05,120 --> 00:40:08,440 Speaker 2: more reactions in them. Lots of speculative ideas about what 867 00:40:08,480 --> 00:40:10,799 Speaker 2: it might have happened billions of years ago to get 868 00:40:10,880 --> 00:40:14,399 Speaker 2: life started, and then that speculation extends all the way 869 00:40:14,440 --> 00:40:17,880 Speaker 2: to like actually getting life out of the ocean. Some 870 00:40:18,040 --> 00:40:21,160 Speaker 2: people think that tide pools are a place that fish 871 00:40:21,719 --> 00:40:25,080 Speaker 2: learned to walk. Basically, being stranded in a tide pool 872 00:40:25,200 --> 00:40:26,920 Speaker 2: meant you better evolve some legs. 873 00:40:27,200 --> 00:40:29,000 Speaker 1: Well, you mean, like some fish we're hanging out by 874 00:40:29,040 --> 00:40:32,279 Speaker 1: the beach by the shore during high type, but then 875 00:40:32,280 --> 00:40:34,399 Speaker 1: when low tie came, they're like, oh, we're stuck here 876 00:40:34,440 --> 00:40:36,279 Speaker 1: in the land, and maybe we should learn to walk. 877 00:40:36,400 --> 00:40:38,120 Speaker 2: You know, that makes me wonder I never thought about 878 00:40:38,120 --> 00:40:41,000 Speaker 2: this do fish enjoy the beach the same way land 879 00:40:41,040 --> 00:40:43,560 Speaker 2: animals do. Do they go near the shore and they're like, ah, 880 00:40:43,640 --> 00:40:45,000 Speaker 2: this is so beautiful and relaxing. 881 00:40:45,120 --> 00:40:47,080 Speaker 1: Interesting, Like do they take vacations at the shore? 882 00:40:47,360 --> 00:40:51,399 Speaker 2: Exactly? Yeah, do fish take vacations at the shore? Deep 883 00:40:51,560 --> 00:40:53,120 Speaker 2: questions were uncovering today. 884 00:40:53,480 --> 00:40:55,400 Speaker 1: I think they kind of do, right, because in the 885 00:40:55,440 --> 00:40:59,120 Speaker 1: deep ocean they're more vulnerable to getting eaten, and there's 886 00:40:59,160 --> 00:41:02,200 Speaker 1: I think more food for them near the shore, So 887 00:41:02,320 --> 00:41:05,480 Speaker 1: it is kind of a kind of a result. It's 888 00:41:05,560 --> 00:41:06,920 Speaker 1: kind of a vacation spot for them. 889 00:41:07,239 --> 00:41:10,400 Speaker 2: Here a physicist and a cartoonist speculate, but marine biology. 890 00:41:10,880 --> 00:41:13,759 Speaker 2: But I think the actual idea speculative as it is, 891 00:41:14,480 --> 00:41:17,280 Speaker 2: is that land walking animals could have started as fish 892 00:41:17,520 --> 00:41:20,560 Speaker 2: stranded in tidepools. Not that like an individual fish of 893 00:41:20,640 --> 00:41:23,600 Speaker 2: course is going to sprout legs, but the fish that 894 00:41:23,719 --> 00:41:26,080 Speaker 2: have this ability to like scramble over a rock or 895 00:41:26,160 --> 00:41:29,359 Speaker 2: two are more likely to survive getting stranded in type 896 00:41:29,400 --> 00:41:29,799 Speaker 2: pool m. 897 00:41:30,239 --> 00:41:33,239 Speaker 1: Like maybe stranded one hundred fish or something. Most of 898 00:41:33,280 --> 00:41:35,880 Speaker 1: them died, but the ones that somehow had some weird 899 00:41:35,960 --> 00:41:37,799 Speaker 1: gene that let them flop around a little bit better 900 00:41:37,880 --> 00:41:42,000 Speaker 1: with their fins. Maybe those eventually evolved into the animals 901 00:41:42,080 --> 00:41:45,120 Speaker 1: that left the ocean and became us exactly. 902 00:41:45,480 --> 00:41:48,640 Speaker 2: And so having tithes on a planet really changes what 903 00:41:48,760 --> 00:41:51,400 Speaker 2: it's like for life to evolve there, to even start 904 00:41:51,480 --> 00:41:55,400 Speaker 2: from pre life organic molecules, and to develop. And so 905 00:41:55,520 --> 00:41:58,520 Speaker 2: when we look out into other solar systems for planets 906 00:41:58,560 --> 00:42:01,480 Speaker 2: that might have life on them, also very interested in 907 00:42:01,640 --> 00:42:04,800 Speaker 2: whether they have moons, stirring the pot down there on 908 00:42:04,880 --> 00:42:05,360 Speaker 2: the surface. 909 00:42:05,560 --> 00:42:07,840 Speaker 1: Well, like, maybe you're saying the only reason we have 910 00:42:07,960 --> 00:42:09,880 Speaker 1: life here on Earth is because we had moon. Like, 911 00:42:09,920 --> 00:42:11,960 Speaker 1: if we hadn't had a moon, maybe life wouldn't have started. 912 00:42:12,120 --> 00:42:13,879 Speaker 2: We don't know, it's just an equals one, but that's 913 00:42:13,920 --> 00:42:16,600 Speaker 2: a really interesting speculation. And if we go out there 914 00:42:16,640 --> 00:42:18,920 Speaker 2: and we search all these solar systems we find a 915 00:42:19,000 --> 00:42:20,799 Speaker 2: bunch of planets with moons that have life on them, 916 00:42:20,840 --> 00:42:23,120 Speaker 2: and a bunch of planets very similar but without a 917 00:42:23,200 --> 00:42:25,480 Speaker 2: moon and no life, then that would be a strong 918 00:42:25,600 --> 00:42:28,160 Speaker 2: argument that you need a moon to get life started. 919 00:42:28,480 --> 00:42:30,399 Speaker 2: But hey, most likely we go out there and find 920 00:42:30,480 --> 00:42:32,000 Speaker 2: something even weirder than we expected. 921 00:42:32,120 --> 00:42:33,880 Speaker 1: Mm, Like, maybe we're all moonies. 922 00:42:35,239 --> 00:42:36,680 Speaker 2: I don't know what that means, but it sounds good. 923 00:42:37,760 --> 00:42:39,560 Speaker 1: I mean, some parts of the Internet will be over 924 00:42:39,640 --> 00:42:43,279 Speaker 1: the moon to learn this truth. All right, Well, that's 925 00:42:43,280 --> 00:42:46,200 Speaker 1: another reminder that there are all these hidden forces all 926 00:42:46,280 --> 00:42:48,840 Speaker 1: around us, pushing and pulling us, and sometimes we're not 927 00:42:48,960 --> 00:42:51,239 Speaker 1: aware of the effects that they might have. But if 928 00:42:51,280 --> 00:42:52,560 Speaker 1: you look at the physics of it, if you look 929 00:42:52,560 --> 00:42:54,680 Speaker 1: at the details, maybe they have the ultimate effect, and 930 00:42:55,200 --> 00:42:57,000 Speaker 1: maybe they're responsible for life itself. 931 00:42:57,080 --> 00:42:59,279 Speaker 2: And the simple physics model of the Solar system of 932 00:42:59,440 --> 00:43:02,400 Speaker 2: just points orbiting each other with gravity isn't enough to 933 00:43:02,480 --> 00:43:05,560 Speaker 2: describe the reality of our lives. And in the origin 934 00:43:05,840 --> 00:43:08,520 Speaker 2: of life, everything is not just pushing and pulling on 935 00:43:08,600 --> 00:43:12,520 Speaker 2: each other. It's squeezing. It's tugging, it's massaging itself. It's 936 00:43:12,640 --> 00:43:16,120 Speaker 2: not just squeezing the ocean. It's actually squeezing our entire planet, 937 00:43:16,400 --> 00:43:19,359 Speaker 2: causing the crust of flex and stimulating earthquakes. But also 938 00:43:19,800 --> 00:43:21,120 Speaker 2: maybe the reason we're here. 939 00:43:21,120 --> 00:43:24,240 Speaker 1: Well, not just the Earth, it's also squeezing us technically. 940 00:43:23,880 --> 00:43:27,560 Speaker 2: Right, Yeah, that's true. Yeah, you have tides as well. 941 00:43:27,680 --> 00:43:30,000 Speaker 1: And does that mean the moon is actively chewing. 942 00:43:29,800 --> 00:43:33,280 Speaker 2: Me, It's trying to spaghettify it, turning. 943 00:43:33,080 --> 00:43:36,480 Speaker 1: Into pasta di slurt me up or to feed to 944 00:43:36,520 --> 00:43:38,560 Speaker 1: the fishes. Is all right, well, we hope you enjoyed that. 945 00:43:39,120 --> 00:43:41,640 Speaker 1: Thanks for joining us, See you next time. 946 00:43:46,320 --> 00:43:49,160 Speaker 2: For more science and curiosity, come find us on social 947 00:43:49,239 --> 00:43:53,120 Speaker 2: media where we answer questions and post videos. We're on Twitter, 948 00:43:53,280 --> 00:43:56,600 Speaker 2: This Earth, Instant and now TikTok. Thanks for listening, and 949 00:43:56,680 --> 00:43:59,320 Speaker 2: remember that Daniel and Jorge Explain the Universe is a 950 00:43:59,440 --> 00:44:05,279 Speaker 2: production iHeartRadio. For more podcasts from iHeartRadio, visit the iHeartRadio app, 951 00:44:05,600 --> 00:44:09,080 Speaker 2: Apple Podcasts, or wherever you listen to your favorite shows