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

what would you find when you got there. Let's start with the bad news. Leprechns are liars. You cannot reach the end of a rainbow that appears in the sky. If you were to mark on a map the place where the rainbow seems to meet the land, and then travel to that location, you would not be standing inside a glorious pillar of colors. There would be nothing there except probably the fresh smell of a recent rain shower. To understand why this is, we need to look at

how rainbows form. Rainbows are created when sunlight reflects and refracts through water. Droplets suspend in the air in front of you while the sun is behind you. Those water droplets act like both a mirror and a prism. Like a mirror, they reflect the sunlight back towards you, but like a prism, they also bend and disperse that light. This is because rays of light shining through the air change speed when they enter a different medium, for example,

droplets of water. This sudden change in speed bends the trajectory of the light and disperses white light into the whole roy g Bib spectrum. The reason you see a nice ordered gradient of colors within a rainbow going from red to violet is because this refraction bends each of the different colors of light at a slightly different angle. So, for example, red light bends at forty two degrees, violet light bends at forty degrees, and all the other colors

are somewhere in between. So okay, let's find a rainbow. To do this, you need to locate your antisolar point. Your antisolar point is the point in space that's one hundred and eighty degrees or exactly opposite from the sun. A simple way to find this is to go outside and look for the shadow of your own head. That's your antisolar point. Now imagine drawing a line straight from the sun through your head to the shadow of your head.

Now look up. If there is a rainbow to be seen, you will find it by facing away from the sun and looking forty two degrees above your antisolar point. Notice that the apparent location of your rainbow depends on three things. Where the sun is, where the water droplets are, and where your eyes are. Change any one of those variables and you'll see a different rainbow or none at all.

So no matter where you see your rainbow, if you try to walk out to meet it, you'll be changing the variable of your own position, and you could be walking forever, or at least until your rainbow disappears. Trying to find the end of a rain rainbow is sort of like trying to walk to the end of your own shadow. Somebody else could stand at the apparent end of your shadow or rainbow, but you will never ever

reach this location yourself. You can, of course, find earthly rainbows in a waterfall or the spray of a sprinkler or hose. You might even perceive yourself to be standing right next to one, depending on the angle of light coming into the water. But here's one more thing. Those rainbows you see in the sky aren't actually bows. Rainbows are circular. Usually when you're standing on the ground, most

of the rainbow is blocked by the horizon. In rare cases, like if you're in an airplane, you'll be able to see the entire rainbow. Hoop, rain loop, rainhole. It's around spectacular beauty, but there's an obvious takeaway from this it doesn't ever actually meet the ground anywhere. Today's episode is based on a videoscript orhoustopworks dot com written by Joe McCormick. To hear more from Joe, check out his podcast stuff

to Blow Your Mind. Brainstuff is a production of iHeartRadio in partnership withhstuffworks dot Com and is produced by Tyler Klang. Before more podcasts my heart Radio, visit the iHeartRadio app, Apple Podcasts, or wherever you listen to your favorite shows.