No, the helicopter isn’t actually floating, you loon.
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What’s happening here is an illusion caused by the camera’s shutter speed. As our friends at Popular Mechanicsexplain it, the blades’ rotation speed and the shutter speed just happen to match up perfectly, causing this delightful effect:
No matter how fast it can shoot, a camera can only capture video one image at a time, and when it’s capturing something spinning as fast as a helicopter blade, it’s missing a whole lot of the action. That accounts for general weirdness, but the above video and other examples like it are a rarer coincidence—when the blade rotation speed and the camera shutter speed match up perfectly and every single frame catches the blade in the same place.
This is the same phenomenon that makes rotating wheels seem like they are moving slower than they really are and LED lights seem like they are blinking on video.
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The LED lights, in particular, seem to blink because LED lights aren’t always “on,” as user cabarne4points out. Rather, LEDs pulse on and off, but at a much faster rate than our eyes can detect. Camera refresh rates can pick it up, though.
Science!
via Digg