ShmoopTube

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[Coop and Dino singing]

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When you're little, anything that's older than you can seem completely ancient. [Boy walking down the stairs]

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That weird boxy TV in your basement?

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Old.

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Photos of your dad from when he was in high school?

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Super duper old. [Photo of boy's Dad stamped]

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That jar of licorice that has been on your Grandma's coffee table since you can remember?

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Probably about as old as the dinosaurs. [Dinosaurs in a field]

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But if you really want to see something truly old, all you have to do is turn on the tap

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in your house.

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Water?

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Now that's old. [Water coming out of a tap]

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How old?

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Well, seeing as all of the water on Earth is the same water that's been on Earth since

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the beginning of time, we'd say it's pretty old.

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Which…seems kind of confusing, right? [Man sitting drinking an espresso]

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After all, water seems to be changing all the time – we drink it, it evaporates, it

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rains, it freezes, we turn it into snowballs and slushies and apple juice... how can the

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water we have today be the same water from billions of years ago? [Water pours into a magicians hat]

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Magic, That's how.

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…Just kidding!

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It's science.

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See, here's the thing: water is constantly changing forms, from a liquid to gas to solid

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and back again.

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But even in all those different forms, it never stops being water. [Coop discussing the different water forms]

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After all, you could put on a clown costume, a cowboy costume, and a gorilla suit, and

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you'd still be you.

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All of this changing is referred to as the water cycle, and it has many different parts: [Dino teaching about the water cycle]

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evaporation, condensation, precipitation, transpiration, run-off, and infiltration.

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Huh, those last two make water sound like some sort of secret agent… [Man struggling to carry a large water bottle]

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But that'd be ridiculous.

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Even if water could infiltrate enemy territory, it wouldn't be able to tell us their secrets

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afterwards.

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…or could it…hm.

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Someone should get the FBI on this… [Men standing in a room having a cup of water]

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Anyway, while we call up the FBI, let's check out each step of the water cycle!

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First up is evaporation, which occurs when water changes from a liquid to a gas. [Coop discussing evaporation]

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Picture a puddle on the ground.

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And then picture the hot sun above.

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The solar energy from the sun causes the exposed water molecules from the puddle to turn into [Water turns into vapor]

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water vapor, which rises up and forms clouds.

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Nope, it's not something out of Harry Potter…it's an example of evaporation.

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Next up is condensation, which is pretty much the exact opposite of evaporation.

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That's because condensation is when water changes from a gas to a liquid. [Dino discussing condensation]

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When the evaporated water molecules in clouds are cooled down enough to turn back into liquid

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water droplets, then that's condensation. [Dark clouds and rain begins to fall]

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And when that rain actually falls down from the clouds into the sky and back down to the

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earth – whether it's as rain, snow, hail, or anything else - we call that precipitation.

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Oops…sorry.

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Should've told you to bring an umbrella to this video… [Man standing in a field and soaked by rain]

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But here's one you probably haven't heard of before... transpiration.

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Transpiration occurs when water is evaporated from plants.

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In other words, when water goes into the plants roots, it slowly travels up through the plant, [Water travelling up through a plant]

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hydrating everything as it goes.

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Eventually, this water reaches small pores on the underside of the plants leaves, where

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it turns into vapor and is released out into the air to be evaporated.

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And that's transpiration!

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We bet your folks don't even know about that one.

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But before water can even get into the plants roots, it has to soak into the ground first. [Water soaking into the ground]

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And thankfully, there's a word for that: it's called infiltration.

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Which explains why the FBI hung up on us when we called…

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And if rain water falls to the ground and doesn't go into the ground, but instead runs

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off elsewhere?

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We've got a word for that too: run-off. [Coop discussing run-off]

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Super clever name, right?

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If precipitation hits the ground and “runs off” into a lake, a river or even a stinky

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sewer, then you've got yourself some run-off.

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All of these different processes are constantly happening, and they all make up the water cycle.

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And it's because of them that we can say that the water here on Earth is some of the oldest [Water vapor]

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stuff around.

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Yup, even older than those funky old bell-bottoms your dad still keeps around for some reason. [Dad dancing in the living room]

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Hm…maybe we can call the FBI and see if they could make those disappear…

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