WEBVTT - BrainStuff Classics: Why Can't You Reach the End of a Rainbow?

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<v Speaker 1>Welcome to Brainstuff, a production of iHeartRadio. Hey Brainstuff, Lauren

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<v Speaker 1>vogel Bomb here with a classic episode of the podcast

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<v Speaker 1>that this one has to do with how rainbows work,

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<v Speaker 1>how to find them, why you can't reach the end

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<v Speaker 1>of one, and how they're not actually bows at all.

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<v Speaker 1>Hey Brainstuff, Lauren Vogelbomb here. As far as get rich

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<v Speaker 1>quick schemes go, stumbling upon gold the end of a

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<v Speaker 1>rainbow sounds pretty delightful. But is it actually possible to

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<v Speaker 1>get to the end of a rainbow? And if so,

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<v Speaker 1>what would you find when you got there. Let's start

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<v Speaker 1>with the bad news. Leprechns are liars. You cannot reach

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<v Speaker 1>the end of a rainbow that appears in the sky.

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<v Speaker 1>If you were to mark on a map the place

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<v Speaker 1>where the rainbow seems to meet the land, and then

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<v Speaker 1>travel to that location, you would not be standing inside

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<v Speaker 1>a glorious pillar of colors. There would be nothing there

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<v Speaker 1>except probably the fresh smell of a recent rain shower.

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<v Speaker 1>To understand why this is, we need to look at

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<v Speaker 1>how rainbows form. Rainbows are created when sunlight reflects and

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<v Speaker 1>refracts through water. Droplets suspend in the air in front

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<v Speaker 1>of you while the sun is behind you. Those water

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<v Speaker 1>droplets act like both a mirror and a prism. Like

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<v Speaker 1>a mirror, they reflect the sunlight back towards you, but

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<v Speaker 1>like a prism, they also bend and disperse that light.

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<v Speaker 1>This is because rays of light shining through the air

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<v Speaker 1>change speed when they enter a different medium, for example,

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<v Speaker 1>droplets of water. This sudden change in speed bends the

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<v Speaker 1>trajectory of the light and disperses white light into the

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<v Speaker 1>whole roy g Bib spectrum. The reason you see a

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<v Speaker 1>nice ordered gradient of colors within a rainbow going from

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<v Speaker 1>red to violet is because this refraction bends each of

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<v Speaker 1>the different colors of light at a slightly different angle. So,

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<v Speaker 1>for example, red light bends at forty two degrees, violet

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<v Speaker 1>light bends at forty degrees, and all the other colors

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<v Speaker 1>are somewhere in between. So okay, let's find a rainbow.

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<v Speaker 1>To do this, you need to locate your antisolar point.

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<v Speaker 1>Your antisolar point is the point in space that's one

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<v Speaker 1>hundred and eighty degrees or exactly opposite from the sun.

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<v Speaker 1>A simple way to find this is to go outside

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<v Speaker 1>and look for the shadow of your own head. That's

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<v Speaker 1>your antisolar point. Now imagine drawing a line straight from

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<v Speaker 1>the sun through your head to the shadow of your head.

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<v Speaker 1>Now look up. If there is a rainbow to be seen,

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<v Speaker 1>you will find it by facing away from the sun

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<v Speaker 1>and looking forty two degrees above your antisolar point. Notice

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<v Speaker 1>that the apparent location of your rainbow depends on three things.

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<v Speaker 1>Where the sun is, where the water droplets are, and

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<v Speaker 1>where your eyes are. Change any one of those variables

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<v Speaker 1>and you'll see a different rainbow or none at all.

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<v Speaker 1>So no matter where you see your rainbow, if you

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<v Speaker 1>try to walk out to meet it, you'll be changing

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<v Speaker 1>the variable of your own position, and you could be

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<v Speaker 1>walking forever, or at least until your rainbow disappears. Trying

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<v Speaker 1>to find the end of a rain rainbow is sort

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<v Speaker 1>of like trying to walk to the end of your

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<v Speaker 1>own shadow. Somebody else could stand at the apparent end

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<v Speaker 1>of your shadow or rainbow, but you will never ever

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<v Speaker 1>reach this location yourself. You can, of course, find earthly

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<v Speaker 1>rainbows in a waterfall or the spray of a sprinkler

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<v Speaker 1>or hose. You might even perceive yourself to be standing

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<v Speaker 1>right next to one, depending on the angle of light

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<v Speaker 1>coming into the water. But here's one more thing. Those

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<v Speaker 1>rainbows you see in the sky aren't actually bows. Rainbows

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<v Speaker 1>are circular. Usually when you're standing on the ground, most

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<v Speaker 1>of the rainbow is blocked by the horizon. In rare cases,

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<v Speaker 1>like if you're in an airplane, you'll be able to

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<v Speaker 1>see the entire rainbow. Hoop, rain loop, rainhole. It's around

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<v Speaker 1>spectacular beauty, but there's an obvious takeaway from this it

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<v Speaker 1>doesn't ever actually meet the ground anywhere. Today's episode is

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<v Speaker 1>based on a videoscript orhoustopworks dot com written by Joe McCormick.

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<v Speaker 1>To hear more from Joe, check out his podcast stuff

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<v Speaker 1>to Blow Your Mind. Brainstuff is a production of iHeartRadio

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<v Speaker 1>in partnership withhstuffworks dot Com and is produced by Tyler Klang.

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