One of the most commonly spread rumors about physics is the direction of toilet swirl, which says that toilets swirl in opposite directions depending on which hemisphere of the Earth you're in. Many YouTubers have set out to debunk this myth by showing that toilets and sinks drain both clockwise and counterclockwise, regardless of hemisphere. But one duo of educational YouTubers have proved the toilet swirl myth true -- water really does drain in opposite directions on different parts of the Earth! It's called the coriolis effect.
According to Science Alert, the project was created by Destin from the YouTube channel SmarterEveryDay and Derek from the channel Veritasium1. Both YouTubers set out to either prove or debunk the toilet swirl myth once and for all by conducting identical experiments in opposite hemispheres. But if that wasn't ambitious enough, the science-minded content creators also decided to make YouTube history by uploading two videos that synchronize perfectly when played at the same time. The effect is a mesmerizing double-screen experience, featuring Destin and Derek finishing each others sentences from opposite ends of the Earth and working together on the toilet swirl question.
You can watch the "Truth About Toilet Swirl" videos below, but they might be easier to synchronize by visiting Science Alert. If you're viewing on this page, play one video and wait for the synchronizer countdown to reach "one," then pause and play the second video. When the second video's countdown reaches one, hit play on the first video and they should sync up perfectly.
According to SmarterEveryDay, the videos attempt the toilet swirl experiment by building two identical kiddie pools in opposite hemispheres at the same time. They built a drain into the center of both pools and filled them with water. After letting the water sit for a day to ensure it was completely still, both YouTubers simultaneously release a valve to begin the draining process and put the toilet swirl to test.
Then Destin and Derek drop food coloring into the pools in the four cardinal directions to track the motion of the water. Sure enough, the water drained clockwise in the northern hemisphere and counterclockwise in the southern hemisphere. While the coriolis effect may never be visible in toilet swirl, it's a real phenomenon. It affects the swirl of hurricanes and cyclones.
You can see a detailed explanation of how the toilet swirl effect works in both videos above, but it has to do with the angular momentum of the Earth and the direction each hemisphere rotates.
What do you think of the toilet swirl experiment? Were you surprised to learn the coriolis effect (aka toilet swirl effect) is real?
[Image credit: SmarterEveryDay]