Have you ever seen a helicopter magically rise in the air without its motor spinning? If not, you are in for a treat. OK, how can that be?
Here is a little well-known secret, the main rotor of the helicopter is actually spinning pretty fast? Fast enough that it perfectly aligns with the frame rate of the camera.
The exact number of rounds per seconds of the motor could be calculated and depends on the frame-rate in which the footage was taken and how many blades pass a point between those frames.
If you want a more thorough explanation on how this happens. you can check out the video below:
[via <a href=”http://digg.com/video/what-in-the-heck-is-going-on”>digg</a>]