Monday, October 13, 2014

Defying Gravity

This video has been on the web for a while now, but just in case you didn’t see it, the link to the video is at the bottom. I highly encourage you watch the video first before I give away its secrets.


Isn’t this sick!? The first time I watched it I couldn’t believe my eyes! How can water seem to defy gravity and bend that way? The crazy part is: this really IS happening to the water!
The hose connected to the front of the speaker vibrates very rapidly when the sound is turned on. At 24 Hz, the hose oscillates between the furthest point away from the speaker and the nearest in a circular motion at 24 oscillations per second. The water leaving the hose follows the same pattern except slowing down slightly due to gravity and wind resistance, creating a spiraling path like the one in the video.

But 24 oscillations per second is so fast! How come the hose appears to stay still? That’s the secret. If you did this experiment on your own you would see the water leaving the hose almost as a spray. The secret is in the camera. A 24 fps camera takes 24 pictures per second. This means it will take a picture every time the hose repeats back to the same point so it appears to be still. When the speaker is changed from 24 Hz to 23 and 25 the camera captures the hose 1/24 of an oscillation earlier or later each second. This makes the water appear to be rising or dropping slowly.
Hope you like the video! Here’s a link to the illusion explanation.




Submitted by Jacob von der Lippe

1 comment:

  1. That is so crazy! Its a shame that you can only see the illusion with a camera shooting at 24 fps. It would be so cool to witness that in person with your own eyes.

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