Episode 7: Mag Water

[0.7s] Saul: Hello, and welcome to Mag World, where we like to ask big questions, make wild guesstimates, and quantify literally everything on a magnitude scale. If you’re new here, you should know that on a magnitude scale, every mag 1 means times 10. To multiply mag numbers, you simply add them together — so 100 is mag 2 and 1,000 is mag 3, and multiplied together that’s mag 5, which is 100,000. That’s all the math you need to know to understand what’s going on in Mag World. Just remember that every order of magnitude is a big deal, because as we say in Mag World, quantity has a quality all of its own. If you wanna learn more about Mag World, come visit our website at magworld.pw. I’m Saul Pwanson, your guide to Mag World, and I’m here with my friend Mike, who is 70% water. Today’s episode is Mag Water. I wanna open with a quote from Sherlock Holmes. I’ve referenced Sherlock Holmes in the past, and it is from the very first Sherlock Holmes story, A Study in Scarlet, when Watson first meets Holmes. He picks up a book and reads a section that’s been annotated, and he takes issue with it. The quote from the book is: “From a drop of water, a logician could infer the possibility of an Atlantic or a Niagara without having seen or heard of one or the other.” Watson takes issue with this, and Sherlock reveals that he wrote this exact article, and of course he believes it — Sherlock Holmes being a famous logician, or at least in his own mind a famous logician. Now, I know that arguing against Sherlock Holmes is like arm wrestling with Superman, but I take issue with this too. I think — and this is exactly the thesis in Mag World — that you can’t know from a drop of water what Niagara would be like. They are radically different things. The scale, the quantity, does actually matter.

[01:52.2] Mike: I agree with you. It’s been raining today.

[01:55.1] Saul: Mm-hmm.

[01:55.5] Mike: We’re in Seattle. It rains a lot.

[01:58.8] Saul: Frequently, anyway.

[02:00.2] Mike: From the rain in Seattle, could one infer a hurricane?

[02:04.3] Saul: Exactly. And there’s a lot to be said for a hurricane besides just the quantity of water — wind speed and everything else. [Mike: Mm-hmm.] But just from the quantity of water, you could not predict the effects of a hurricane.

[02:17.7] Mike: No. I think you’ve interacted with water on several scales, right? A drop of water drops on your skillet, bounces around. There’s a little round drop on your windshield. There’s surface tension keeping it in this shape.

[02:34.6] Saul: And a drop of water can’t be 10 times as big. It won’t hold together as a drop. [Mike: Mm-hmm.] And you can’t swim in a drop of water. You can’t swim in a bathtub, but you can swim in a pool. So before we get into the actual scales, let’s talk about the units we use for water. The main unit for water is volume, and that’s measured in liters.

[02:57.8] Mike: Liters.

[02:58.2] Saul: That’s the SI unit.

[02:59.8] Mike: How much can a bladder hold?

[03:01.5] Saul: That’s a good question. Let me guess — somewhere between one and 10 liters. It’s not less than a liter, and it’s not more than 10 liters.

[03:13.7] Mike: Yeah, certainly.

[03:15.0] Saul: So I say that mag 0 liters is how much a bladder can hold.

[03:17.3] Mike: Mag 0 liters, yeah, let’s go with that.

[03:19.2] Saul: Do you have an absolute, exact answer?

[03:20.7] Mike: No, I just — I was gonna guess one.

[03:25.9] Mike: I feel like that is very — I’ve done that. I’ve never done 10.

[03:32.8] Saul: I hope not. Exactly. So a two-liter of soda is mag 0 liters, and now I wanna talk about the smaller thing. We were talking about a drop of water. A standard unit for volume is the milliliter — a thousandth of a liter. That’s the same thing as a cc, a cubic centimeter. A cubic centimeter of water is a milliliter, and that’s what we use to measure certain medical treatments in. Like, 10 cc of saline.

[04:08.4] Mike: And do you know the approximate weight of one cc or one milliliter?

[04:12.4] Saul: I do. The approximate mass of one cc is — well, you were quizzing me?

[04:19.9] Mike: I was quizzing, yeah. It’s a gram.

[04:21.8] Saul: It’s a gram. It’s not exactly a gram — it varies with temperature — but at four degrees Celsius, it is so close to being a gram.

[04:30.2] Mike: Any time I’m using it outside of a science lab, it’s a gram.

[04:35.9] Saul: Yeah, exactly. So one gram per milliliter, and there are 1,000 of those in a liter, so a liter’s mass is a kilogram. And because of this, a cubic meter of water — which is yay big, a meter on each side —

[05:00.4] Mike: Saul is holding his hands about a meter apart right now.

[05:03.7] Saul: You know, yay big. Maybe a little more (your arms can’t stretch that far) or a little less — but yay big, about a meter. A cubic meter of water has 1,000 liters in it, and so a cubic meter of water weighs one metric ton.

[05:25.1] Mike: That’s a lot of water.

[05:25.9] Saul: That’s a lot of water.

[05:26.8] Mike: That’s why I can’t put a hot tub on my deck.

[05:29.4] Saul: Exactly. I actually was thinking about this — it doesn’t seem right. “A cubic meter of water, that can’t weigh a ton.” But then I think about carrying one of my emergency water containers, which is only five gallons or so — and that’s some tens of kilograms. It actually is a workout to carry those things. I would not want to have a cubic meter of water thrust upon me.

[05:53.6] Mike: Have you ever had to carry water places over long distances?

[05:57.4] Saul: Well, backpacking, for instance.

[05:59.2] Saul: It weighs a lot.

[06:01.7] Mike: I’ve been in the desert and had to carry gallons before. It is incredibly tiring to travel with, and then you pee — and you’re like, “What a waste.”

[06:11.5] Saul: I actually don’t like carrying it, so I wind up drinking it as though drinking it is less effort, because for some reason I’m not carrying it anymore. I don’t know how that works, but it feels like that’s the case. Maybe it’s easier to carry inside than outside. Anyway, that is the human size scale of water: from a milliliter to a liter to a thousand liters. So mag 0 is a two-liter, and we were talking about a drop of water. A milliliter of water is multiple drops — about 20 droplets in a milliliter, right? A single milliliter is a lot more than a drop. You can’t have a drop that big.

[06:55.8] Mike: Mm-hmm.

[06:56.2] Saul: So mag -3 is a milliliter, mag -4 is a drop, and mag -5 isn’t even a droplet — it’s mist, drizzle hanging in the air. Different qualities.

[07:05.6] Mike: Water you can inhale.

[07:07.0] Saul: Right. Going up the scale, mag 4 liters is any kind of residential pool. An Olympic pool — do you wanna guess how big an Olympic pool is in liters?

[07:23.3] Mike: Mag 6.

[07:25.1] Saul: It is mag 6 — mag 6.4.

[07:28.4] Mike: I think I cheated, because it just feels like you’re leading me up the scale.

[07:31.1] Saul: It’s true, I am. But yeah — lakes are mag 8 to mag 12 volume, the Great Lakes are mag 13 to mag 16, and the Pacific Ocean is mag 20.9.

[07:48.5] Mike: .9?

[07:49.3] Saul: Liters.

[07:49.6] Mike: Could you be more Pacific?

[07:51.1] Saul: Wow. All of the water on Earth is mag 21.1. So basically all the water on Earth is the Pacific Ocean. That’s not literally true — there’s the Atlantic Ocean too — but the Pacific is about 60% of the water on Earth, and between the Pacific and Atlantic, that is virtually all of the water on Earth. Everything else is a rounding error. There’s so much water in the oceans nothing else really matters. I shouldn’t say it doesn’t matter — obviously, it matters to us quite a bit.

[08:20.2] Mike: I care kinda.

[08:21.2] Saul: Right. We care about our little puddles, our little pothole lakes. The ocean is just so big and so vast. So one of the issues I take with Sherlock’s quote — he’s talking about a drop of water, and from that you could infer the possibility of a Niagara. Well, Niagara is important because it’s a flow. It’s water dropping off a cliff. So one mistake we’re making here is comparing a droplet of water, which is a volume, to the flow of water, which is a much different kind of unit.

[08:52.2] Saul: But I wanna talk about the flow of water on a separate scale here. So we talked about volume of water in liters. Now we’re gonna talk about flow — liters per second. Do you know a piece called the Moldau?

[09:03.6] Mike: The who?

[09:03.8] Saul: It’s a famous classical piece by Smetana —

[09:08.9] Mike: I’m familiar.

[09:09.5] Saul: It’s a six-piece tone poem series, and the second one is the Moldau. The whole series is about his homeland, Czechoslovakia, and the second one is about a river that goes through Czechoslovakia, the Moldau. It’s a musical representation of a river, and it’s really beautiful. It starts from the simple trickle of two different little streams that come together and form a much wider river that passes through a hunt going on in the forest, then a peasant wedding on the banks, then the moonlit dances of the mermaids. It’s a really lovely little piece.

[09:46.2] Mike: I’d really like to listen to this. Will you link it in the show notes?

[09:49.3] Saul: Absolutely. So I wanna start from the actual flow here, because one of the smallest flows is called a seep. The word seep comes from the noun — a seep is water popping out of a rock, the groundwater bubbling up to the surface from below. That’s about mag -2 — basically a couple of milliliters per second, a little trickle. Mag 0 liters per second is like a spring. Going up the scale — and this was the most cursory examination of these terms — it really seems like it goes from a spring to a brook to a creek, and then mag 3 is a river. I can see in my own head how a spring is quite different from a brook, a babbling brook is not a spring it’s just smaller, and then a creek — you can actually have fish in a creek. And then mag 3 is a river.

[10:51.0] Mike: That is fascinating. One of the favorite hikes I ever took is a three-day river journey through what’s called Paria Canyon. It starts in a slot canyon. Have you ever been in a slot canyon?

[11:08.8] Saul: No.

[11:09.7] Mike: It’s 30 feet deep and shoulder width, going through sandstone. You’re walking through this very narrow canyon, eventually widens out to 10 meters wide with walls 40 or 50 feet high, opens out into a wider, all these tributaries connecting to each other until you get to the Colorado. So you go from this tiny little thing into a big thing — going from a brook to a river, going from the slot canyon to the canyon. Makes me really wanna listen to this piece as it audibly describes small to big water. Every piece feels distinct.

[11:54.5] Saul: Yes. So let’s talk about some famous rivers — the Rhine, the Nile, the Danube, the Columbia, the Missouri. Do you wanna guess how much flow they have? If the first thing you called an actual river is mag 3, how big are these well-known rivers in liters per second?

[12:14.4] Mike: Liters per second.

[12:15.2] Saul: And it should map up — if you have a certain flow per second, you can just multiply by mag 7.5 to get how much flow per year.

[12:22.6] Mike: Uh-huh. So mag 3 is a ton of water — mag 3 per second.

[12:31.5] Saul: That’d be a ton of water. A basic river, more than a creek — that’s a metric ton of water a second.

[12:38.0] Mike: Yeah. I’m trying to think of volumes here. Like the Cedar River, I could see a chunk that big coming through every second.

[12:47.5] Saul: These are big rivers, the Nile —

[12:49.7] Mike: These are bigger than whatever river Niagara Falls is on. I find it easier to think about water falling than water in an unknown depth. Have you been to Niagara Falls?

[13:03.3] Mike: Yeah.

[13:03.8] Saul: So you’ve seen the actual water falling? I’m gonna spoil this for you: those rivers are all mag 6 — actually mag 6 and a half — volume. And Niagara Falls is also mag 6.4. Niagara Falls is not special. It’s a big river, but just as big as the Columbia or the Danube. The big deal is that it’s falling off a cliff.

[13:25.1] Mike: Yeah. Well, the big deal is that you can see it all.

[13:28.4] Saul: Yeah, it’s epic to see it.

[13:30.9] Mike: Like the Columbia is great just because — depending on where you are — you’re either in a canyon and it’s huge, or you’re on a plain and it’s huge. But you don’t see how much water there is, you see the geography around it.

[13:48.0] Saul: Right. And there’s a difference between the surface area of something — a lake or a pond or a river — and the depth. The depth matters too. You can be carrying along a lot of water because of the depth that you can’t necessarily see. Rivers can be deceptive.

[14:02.6] Mike: So a boring old neighborhood river is gonna be a mag 3.

[14:07.0] Saul: Yep.

[14:07.5] Mike: And a big river is gonna be mag 6.

[14:10.7] Saul: Yes, a well-known river.

[14:11.8] Mike: A well-known river is going to be a mag 6. So that’s mag 3 bigger — a thousand times bigger.

[14:19.3] Saul: Yeah, exactly — more flow specifically.

[14:23.5] Saul: Okay, so those well-known rivers. Then we have the Mississippi. The Mississippi is mag 7.1 — mag 7. That’s like three times as big as those. Mag 7 rivers are continent-cutting rivers. Huge deals. And the Amazon is in a category all on its own.

[14:48.8] Mike: Is that a mag 9?

[14:49.7] Saul: It’s a mag 8.3 at the exit, at the flow out into the ocean. It has more flow than the next six rivers combined.

[14:58.8] Mike: Dang.

[14:59.8] Saul: It’s a class unto itself. It’s hard to even find pictures of the Amazon — I think it’s too big to even see at that scale. You can’t even comprehend it.

[15:17.8] Mike: Speaking of flows of water — what are tides? I don’t know, how much water comes in and out of, say, Puget Sound every day?

[15:29.6] Saul: I don’t know the answer to that.

[15:32.6] Saul: It’s tangential, but I was gonna bring up a fact. You’ve heard of the Thames River in England? It’s one of the most famous rivers. It feels like it should be a mag 6 river because it’s kind of on the same general order of magnitude in terms of surface area, even depth, as those other rivers.

[15:53.9] Mike: Isn’t that a very slow river, though?

[15:55.3] Saul: It is. It’s mag 4.8 flow — almost mag 5. A whole order of magnitude less. Actually, one and a half orders of magnitude less than those other rivers.

[16:05.9] Mike: Wow.

[16:06.8] Saul: And it’s because it’s right next to the ocean, and the tides push back against the river. It’s backed up for about 100 kilometers. It doesn’t actually flow that much for how big it is. It’s a very different quality of river.

[16:21.5] Saul: I was gonna think about doing some math today.

[16:27.6] Mike: On Mag World?

[16:28.5] Saul: I know — mind-blowing. One of the questions I had: how much water is in the air at Niagara Falls? If we consider Niagara Falls not as the flow, but literally the sum of all the water falling through the air at any given point in time — how much water is it? Does it compare to a lake? And if so, what size of lake?

[16:49.5] Mike: You mean how much liquid water is not either in the river or in the pool?

[16:55.3] Saul: Yep.

[16:56.3] Mike: Got it.

[16:56.7] Saul: It turns out the amount of water flowing through Niagara Falls is an Olympic swimming pool every second. So it’s three pools in the air.

[17:09.8] Mike: Just hanging in the air.

[17:10.4] Saul: Hanging out. Let’s talk about the difference between salt water and fresh water.

[17:17.4] Mike: Ooh, I know this one.

[17:18.9] Saul: Yeah?

[17:19.5] Mike: One has salt.

[17:20.5] Saul: One has salt. Do you know how salt water comes around? I did not know this before today.

[17:25.7] Mike: You put salt in it.

[17:27.4] Saul: Salt is everywhere. All the rivers have little amounts of salt in them, minerals and stuff. First of all, lakes are just wide spots in the river system —

[17:37.8] Mike: No, they’re just lazy, lazy rivers.

[17:39.6] Saul: Right — the river goes into a lake and it’s like, “Oh, here’s a base, I’m just gonna hang out here for a while, take a bath.” Then it overflows and goes out, or it seeps into the groundwater. It’s all part of this system; it just happens to be a —

[17:51.1] Mike: Or in a couple rare circumstances, it don’t go nowhere.

[17:54.4] Saul: Well, that’s the difference between freshwater and saltwater. If it don’t go nowhere, the lake becomes a saltwater lake, because there’s nowhere for the salt to go. The water ends up evaporating, and over thousands of years concentrates into saltwater.

[18:07.1] Mike: Oh, millions of years of salt.

[18:09.1] Saul: It turns out it’s not that long — it’s thousands of years. Check this out: there’s the Great Salt Lake in Utah. They built, in the 1950s I think, a railroad causeway across it that cuts the lake into two.

[18:26.2] Mike: Oh.

[18:26.6] Saul: There’s basically no passage between them. Actually a little passage, but kind of like a straw between two giant bowls. It’s almost nothing. And in the past 80 years, the amount of salt water on one side is twice the salt percentage of the other side.

[18:45.2] Mike: Really?

[18:45.7] Saul: Yeah. It changed in that amount of time. So saltwater lakes have no drain. The Dead Sea is a famous one — supremely salty. And there are things like the Caspian Sea. There’s a wide range of saltiness. The ocean is 3.5% salt. The Dead Sea has 30%, 10 times as much salt.

[19:08.3] Mike: And then the Adriatic Sea is slightly saltier just because it’s more inland and gets less mixing than the open ocean.

[19:17.3] Saul: Oh — slightly saltier than the open ocean?

[19:19.5] Mike: Yeah. You have the open ocean, then the Mediterranean, then the Adriatic. Because of the differential mixing, you end up slightly saltier the further inland you get.

[19:33.1] Saul: Nice. Have you been?

[19:35.1] Mike: Yes. It’s easy to remember things about places you’ve been — well, because I floated better there.

[19:41.9] Saul: Can you feel it?

[19:42.8] Mike: It’s noticeable, yeah. You’ve been to a pool, and then been in the ocean on vacation or something — have you noticed how obvious it is?

[19:53.9] Saul: I have not had the guts to float in the open ocean. There’s a lot going on. It’s kinda busy. There’s a lot of stuff in the ocean, too.

[20:05.0] Mike: The stuff is the best part about the ocean.

[20:07.7] Saul: Oh, it’s a lot of fish poop.

[20:08.2] Mike: I’ve seen you at a sushi restaurant.

[20:13.1] Saul: Yes, it’s true.

[20:14.1] Mike: And I’ve also been to the Great Salt Lake, which — again, another order of magnitude of buoyancy.

[20:20.9] Saul: Yeah! I should try that out at the Great Salt Lake. Go out, hang out, buoyant myself, buoy myself. So that was saltwater. Let’s talk about frozen water.

[20:34.0] Mike: Dun, dun, dun, dun, dun, dun, dun. Dun, dun, dun, dun, dun, dun, dun, dun. Ice, ice baby.

[20:39.7] Saul: Oh my God — wow, nice. Yeah, you’re from an era; you know that song. So when water freezes, it freezes at a higher temperature if there’s no salt in it. When you freeze water, you’re gonna have basically fresh water. The ice is fresh water. There is such a thing as sea ice, because the salt water kinda gets in between there, but frozen water by itself is fresh water.

[21:04.2] Saul: All of the ice sheets and glaciers are frozen fresh water. In fact, most of the fresh water we have on this planet is locked up in ice sheets and glaciers — most of it just in ice sheets. Glaciers are kind of inconsequential for this.

[21:21.7] Mike: So we’re talking about Antarctica?

[21:24.4] Saul: There are two big ice sheets — one in Antarctica, the other in —

[21:29.8] Mike: Greenland.

[21:30.2] Saul: Greenland. Those are the two. Mag 19 liters of water in the Antarctic ice sheet.

[21:38.4] Mike: Mag 19 liters? How much is in the Pacific Ocean?

[21:42.5] Saul: Mag 20.9. So about 1%.

[21:47.8] Mike: So 1%.

[21:50.0] Saul: Actually I’m wrong — it’s mag 19.4, so it’s more like 3% of the world’s water is fresh water. And almost all of that is locked up in the ice sheets.

[21:59.2] Mike: Wow.

[22:00.7] Mike: Is that mag 19 in all ice sheets, or just the Antarctic?

[22:04.3] Saul: Just the Antarctic one is mag 19.4. But in Mag World, basically it’s all of it. The Greenland ice sheet is mag 18.5. The amount of fresh water is still mag 19.4 in the ice sheets. I was looking up — because of global warming, how much ice have we lost? It turns out we’ve lost a fair amount of mountain glaciers — 5 to 6% over the last 55 years. That’s actually a lot of melt. We can visibly see those mountain glaciers receding. But mountain glaciers are only mag 17 liters. Compared to the Antarctic at mag 19, it’s a drop in the bucket. And the amount of melt we’ve had in those ice sheets is actually like 0.01%. Very little. So when you have ice melting, locally there are big deals happening, and over the long haul it’s gonna be a big deal — but currently we actually haven’t experienced that much ice melt in the totality of ice.

[23:07.1] Mike: Interesting.

[23:07.8] Saul: The other thing I learned about ice floating in the ocean: there are names for the various sizes. Do you know what a growler is?

[23:18.7] Mike: Two liters of beer.

[23:21.2] Saul: Very close. It is that, but it’s also a little iceberg that doesn’t go up more than a meter out of the water.

[23:31.1] Mike: Growl.

[23:31.8] Saul: Yeah. And there are little bergy bits, which are less than five meters hanging off a thing. Bergy bits, that’s the official name.

[23:39.9] Mike: Bergy bits?

[23:40.7] Saul: Bergy bits. And an iceberg is bigger than that. Your glaciers are mag 10 or 11 liters of water. And all glaciers combined are mag 17 liters of water, compared to mag 19 in the ice sheets.

[23:58.5] Mike: Let’s go back to icebergs. I wanna know the size of icebergs. Sometimes these big chunks come off, and then there’s these growlers. What is the size of, like, the Titanic iceberg, as an example of a famous iceberg?

[24:16.0] Saul: I looked exactly that up. It’s a medium-size iceberg — on the order of mag 7 liters. I don’t know the exact number.

[24:26.5] Mike: So a little pond, a little floating pond.

[24:28.3] Saul: A frozen floating pond. Of course, it’s a little more jagged than that. If it was just a flat surface you could roller skate or ice skate on, that probably wouldn’t have sunk the Titanic. But you make it a vertical column and it’s a much bigger deal — it cuts into your boat’s hull.

[24:44.4] Mike: Aw.

[24:46.4] Saul: I know. Let’s talk about precipitation — literal liquid water in the atmosphere that comes out of the atmosphere. The amount of precipitation in a single event: a moderate rain is about mag 10 liters, which is actually a lake.

[25:05.7] Saul: Of course, if you dropped a lake all on one single point, you’d not be having a good time.

[25:10.1] Mike: You’d be making another lake.

[25:11.7] Saul: But you do it over the course of a day or two over a wider range, and you are making a little bit of lake. You’re filling up the groundwater supplies for that region — the watershed.

[25:24.5] Saul: That’s mag 10 for moderate rain. Mag 10 and a half liters for a heavy thunderstorm.

[25:30.3] Mike: What area are we talking about when you say a rain?

[25:36.5] Saul: There are thunderstorm cells — t-storm cells. That’s the numbers I was getting here. This is a single instance of a rainstorm. You’re right, it could happen over a huge region too, but this is more like a single particular event.

[25:53.6] Saul: A flash flood is mag 11. So not that much more than a moderate rain — about 10 times moderate rain creates a flash flood. A hurricane dumps about mag 14 liters.

[26:06.1] Mike: Hoo, boy.

[26:07.0] Saul: A thousand times more. Now, I think that’s over the lifetime of the hurricane, so it’s not like it happens all in one place. Hurricanes famously move around.

[26:19.8] Mike: They’re huge and they move and they last for days.

[26:24.5] Saul: Yeah. But still, a thousand times more than a flash flood. Basically it’s flash floods all along its course — just dumping water and water and water. The biggest destructive energy of a hurricane is not the water amount but the energy behind it; still, the water amount causes all kinds of problems.

[26:42.6] Mike: Well, like you were saying, yeah, a lake gets dumped on Seattle, but it’s refilling the groundwater reservoirs, going into the sewer system, it gets handled — but there’s a capacity. What happens when your groundwater is all full up? What happens when your sewers are processing as much as they can? Even if it’s over a longer period of time, there’s surely a capacity.

[27:12.8] Saul: Yes. I was looking at this with regard to monsoons too. Monsoons actually aren’t much more water — they’re just sustained for weeks and weeks. It’s basically a thunderstorm, or a very decent rainstorm, but if it goes on for days and days and weeks, you’re gonna have the same problems. Your literal groundwater supply has problems if you don’t have enough and you have problems if you have too much. As with all things in life: the dose is the poison.

[27:42.0] Saul: So let’s talk about human usage of water. We were talking about the amount of fresh water available to humans. We have mag 19 freshwater on the planet — but humans can’t directly use saltwater, so it’s only the freshwater, and most of that freshwater is locked up in the ice sheets. Humans have only about mag 17 freshwater available in lakes, groundwater supplies, rivers, and stuff like that. Of that mag 17 — which is still a large number of liters of water — each human needs mag 0 liters of water a day.

[28:20.8] Mike: Biologically.

[28:21.8] Saul: Biologically, exactly. I have been camping in the desert, and the rule of thumb is one gallon per person per day. That’s what you should bring to sustain yourself.

[28:32.9] Mike: Two liters. Or four liters.

[28:35.2] Saul: Four liters?

[28:35.3] Mike: Four liters.

[28:36.0] Saul: Per gallon — yep. So maybe a half mag of water. That’s basically drinking water, maybe a little cooking water. But how much water does each individual person in the US use per day?

[28:52.1] Mike: Mag 1?

[28:53.6] Saul: It’s mag 2 and a half. About 300 liters of water a day. The other number I have here: how much water is used to make a hamburger? Literally, if you’re growing a cow for the beef — you have to feed the cow the feed, which you have to use water to irrigate, and you have to feed the cow water to drink — how much water is used ultimately to make one single hamburger?

[29:27.7] Mike: 500 liters.

[29:29.1] Saul: It is actually 2,500 liters.

[29:32.9] Mike: 2,500 liters.

[29:33.9] Saul: It is as much water to make a hamburger as to make a T-shirt. A T-shirt is mag 3.4 liters — and that’s a durable good. All the cotton has to be grown, the cotton processed. But yeah, a single hamburger is about as much as a T-shirt to make. When I say mag 2.5 a day, some people eat a burger most days, and that isn’t factored in.

[30:01.2] Mike: No.

[30:01.2] Saul: So the actual usage of water — that I have here for US personal usage —

[30:04.9] Mike: I can believe 2.5 mag. The showers, your toilet.

[30:10.3] Saul: Watering your lawn. This is your household consumption.

[30:15.0] Mike: Yeah. 100 gallons a day is totally plausible.

[30:21.2] Saul: Each toilet flush is about a half mag — three liters of water or so. Every shower is about mag 2 liters of water. A shower or a bath. The bath is a little more, but it’s basically a mag 2 thing. Running your sprinkler for an hour is mag 3 liters of water. A car wash is the other one — how much does a car wash use?

[30:47.5] Mike: Ooh, that’s a good question. I’m imagining driving my car into the little tunnel. Start spraying. And it keeps spraying for about four minutes. I’m gonna say that ends up being a mag 2 and a half.

[31:09.2] Saul: Wow. Dead on.

[31:10.8] Mike: Really?

[31:11.3] Saul: Really. Very nice.

[31:13.2] Saul: Now here’s the thing — you’re gonna use more water doing it yourself with a hose. Those car washes are really efficient. The spraying they’re doing is like a fine mist. It’s more than that, but the comparison to a hose is less water. It’s like washing the dishes in the sink versus using a dishwasher.

[31:31.2] Mike: Oh yeah. It’s in their interest to cut down their cost as much as possible.

[31:35.4] Mike: And water costs.

[31:36.8] Saul: Water costs, totally. So mag 2.5 for a car wash. More water is being used to make a hamburger that you’re gonna eat than to wash a car. Which is surprising.

[31:51.0] Mike: The direct water costs of washing your car — I’m sure the creation of all those different detergents and waxes —

[31:59.0] Saul: Is a separate issue.

[32:00.9] Saul: 100%. Let’s pollute the water in addition to that. But the thing I wanted to bring up is that all water usage is local. Even if we found a tremendous fresh water supply that was the best water possible, 1,000 miles away —

[32:13.2] Mike: Oh, I found one.

[32:14.1] Saul: Yeah?

[32:14.6] Mike: You told me about it. It’s in Antarctica.

[32:17.1] Saul: Right. And there’s one in Greenland too.

[32:19.1] Mike: Oh, I guess that one’s a little closer. We should use that one.

[32:21.3] Saul: Right. I can’t even go there. Exactly — it’s not gonna help us out. You have to cart that water, it’s not worth it. All your water usage is local. The difference is that all the water usage to make that burger is done far away. Supposedly they’re dealing with the water supplies needed to make the burger in the place that burger’s being made, and when you eat the burger here you’re not using up 3,000 liters of water. But when you’re using a car wash, you literally are using that municipal water supply.

[32:56.4] Mike: Before any listeners respond to you, I do have a little pushback on “all water usage is local.” Because rivers are not local. The water usage rights along rivers is a very old and very contentious aspect of water law. The Columbia River — our local one — is one example where you have municipal uses, agricultural uses, industrial uses, and there’s a first in time, first in right to water usage. But then there’s priorities for municipal usage. There’s carve-outs for fish passage — you need minimum flows to maintain fish populations. All these different people up and downstream have claims to this water. So while true that water usage is local, the locally apportioned water is a product of law, not necessarily a product of availability.

[34:03.4] Saul: Yeah, you’re totally right. Thank you for schooling me on that. I’m gonna jump ahead here for a second. The Dead Sea we talked about a little earlier — I don’t know if you know this, but the Dead Sea is dying.

[34:16.0] Mike: What?

[34:17.1] Saul: Yeah. The Dead Sea is about half the surface area it was 60 or 70 years ago. It’s visible on a map.

[34:26.7] Mike: The Dead Sea has a drought problem.

[34:29.5] Saul: Hold on, I’ll tell you why. It’s going down by a meter and a half a year. Hotels that were on the coast of the Dead Sea are now hundreds of meters back from the actual Dead Sea itself. It’s because they diverted the Jordan River that feeds the Dead Sea. They started doing this in the ’60s, and it wasn’t just one person — multiple projects, multiple countries. Jordan and Israel and Syria all wanted their piece of this river, and they all took it, and now the Jordan River is 10% of the flow it was previously. That lack of 90% means it’s not feeding the Dead Sea, and the water is evaporating and not being refilled.

[35:18.6] Mike: How can hotel owners on the Dead Sea possibly claim that our lakefront property is more important than your water use upstream? This is what fights happen all the time over water rights — because it’s a limited resource. As you stated, the amount of water on Earth compared to the amount of usable water on Earth — drastically different.

[35:48.8] Mike: It’s fascinating that I didn’t know —

[35:52.7] Saul: The Dead Sea is dying.

[35:53.7] Mike: The Dead Sea is dying.

[35:54.4] Saul: I didn’t either, but it totally is.

[35:56.2] Mike: So at some point it’s gonna be the scenic — Great Salt Flat?

[36:00.9] Saul: Basically. So I asked, “Okay, if it’s evaporating and there’s nothing refilling it, is this just getting saltier and saltier?”

[36:09.0] Mike: I would say no.

[36:10.0] Saul: Why not?

[36:10.8] Mike: Because it’s already reached capacity.

[36:12.6] Saul: It is saturated — 35% or whatever, its maximum.

[36:15.9] Mike: That’s why it’s all crystallized around the edges.

[36:18.1] Saul: Not just on the edges. Apparently it snows salt in the thing. It precipitates out right in there because the water can’t hold any more. It’s like snowing salt constantly. There are little pillars of salt. It’s growing by 10 centimeters a year, of salt covering the bottom. So we are totally gonna have the Dead Sea flats.

[36:36.4] Mike: Well, if you ever wanted to float in it, you gotta go now.

[36:38.8] Saul: Let’s talk briefly about the other human uses of water. We talked about individual human water usage. Let’s talk about large-scale human usage — agriculture and industry.

[36:50.8] Mike: Oh, because you had mentioned the hamburger. A hamburger is 2,500 liters.

[37:01.0] Saul: All told, yeah.

[37:02.1] Mike: And so a lot of our water goes into agriculture. I’m sure you can tell me exactly how much of the freshwater —

[37:10.9] Saul: I’ll do it right now.

[37:12.0] Mike: Tell me.

[37:12.8] Saul: 70% of our water consumption as humans goes to agriculture. Irrigation alone is 37% of all our usage.

[37:19.7] Mike: 37% of all our usage. So what’s the other agricultural?

[37:24.0] Saul: Well, feeding livestock. There are non-irrigation uses of water. Agriculture is some 70% of our usage, and then industry is another large percent. 20% of our water usage as humans is industry — mining, processing, refining. Somebody asked me, does fracking matter? It turns out on a national scale, fracking is like 1%. All of mining is 1% of water usage. It doesn’t really count nationally. But for those local communities, it totally counts, because it’s using all of their water.

[38:06.9] Saul: So the biggest use of water in agriculture is irrigation. The biggest use of water in industry is actually thermal electric cooling. Basically what we have in power plants — water going in and coming out, being heated up, converting to steam, pouring out the top as steam, or being flushed into the ocean. That’s 40% of industrial use of water, the plurality of water usage in industry.

[38:38.4] Mike: So being used not to be used up, but for its energy-transferring.

[38:44.8] Saul: Yes. And it may be used up. There are open-loop and closed-loop systems. In fact, I learned in the course of this research that we as the US hit — let’s call it peak water in 1980. Our water usage peaked in 1980 and has been falling since.

[39:03.6] Mike: Really?

[39:04.2] Saul: Yeah. We have 40% more people, but our water usage is actually lower than the peak in 1980. Because we’ve gone to closed-loop systems. We have actually done a pretty decent job nationally of conserving water.

[39:18.5] Mike: Yeah, I mean, some of it probably because we’ve had to. I know that lots of reservoirs are much lower now than they were when they were created in the mid-1900s. These reservoirs in the Southwest and in California were created at a time when there was higher than normal precipitation, with the expectation it would continue.

[39:47.3] Saul: When I think about peak water happening in 1980, it might not be that we’re doing such a great job of conservation now, but that we were doing such a terrible job of conservation then that the number is just super high.

[39:58.9] Mike: I grew up in California. I remember as a young kid in the ’80s, all sorts of signs and propaganda: “Limit your water use, shut off the tap, limit your showers. If it’s yellow, let it mellow. If it’s brown, flush it down.”

[40:17.5] Saul: I still abide by that.

[40:19.5] Mike: Yeah. I think for my folks, it was new — but for me, I grew up with it. So perhaps also just habits.

[40:32.6] Saul: But again, most of our usage is not domestic like that. Most of it is going toward agriculture. You can do a lot more closing the loop for a power plant than telling all of your citizens to not flush as much.

[40:47.0] Mike: Certainly.

[40:49.0] Saul: That is all I have for mag water. I have a couple of afternotes I wanna talk about.

[40:55.2] Mike: Ooh.

[40:55.7] Saul: I just came across a link on one of my news aggregating sites, and I’m gonna post this to the show notes too. It’s called “What’s My JND?” Do you remember JND?

[41:06.7] Mike: Yeah, Just Noticeable Difference?

[41:07.8] Saul: Yeah.

[41:08.4] Mike: What did we call it?

[41:12.1] Saul: A fetch.

[41:12.7] Mike: A fetch.

[41:13.6] Mike: Yeah.

[41:13.6] Saul: What’s My — exactly. And this —

[41:15.0] Mike: What’s My Fetch?

[41:15.4] Saul: This person was doing it with color. “Okay, we’re gonna start with a big color difference. Tell me where on the screen your color changes.”

[41:23.3] Mike: Oh my god. Yes. Color fetches have led to so many arguments in the paint aisle at Home Depot.

[41:32.0] Saul: Exactly. So he splits the screen into two colors, and says, “Find the place where that split happens.” If you can find it, you can differentiate between the two. If you can’t find it, you can’t. He starts with a big brown versus blue, and then gradually brings the colors together so at some point you’re like, “I don’t know where the division line is” — and that’s how you figure out your JND. Just Noticeable Color Difference.

[41:56.3] Mike: Fascinating.

[41:56.9] Saul: Yeah.

[41:57.1] Mike: I love it. Can you post that link? I need that.

[42:00.1] Saul: I will.

[42:02.5] Saul: Awesome, Mike. Thank you so much. Next time, I’m thinking we should talk about mag energy.

[42:10.2] Mike: Hm.

[42:10.6] Saul: I’m not sure if it’s gonna be mag energy or mag time, but those are kinda my two main contenders.

[42:16.3] Mike: Big mag energy.

[42:17.4] Saul: Big mag energy, exactly.

[42:19.5] Saul: Of course it’s a big topic, and I’m looking forward to talking with you about that whole thing.

[42:25.0] Mike: I am too. Let’s do the math.

[42:26.4] Saul: Okay, let’s do the math, Mike. Thanks very much for being here.