Which Way is the Propeller Spinning?

This is a video of a plane's propeller as it comes in to land, and it shows the propeller appearing to stop rotating and change directions multiple times. It's a great example of 'aliasing' in signal and video processing.
Related videos: (see www.iaincolling... )
• How to Understand Aliasing in Digital Sampling • How to Understand Alia...
• Aliasing Ambiguity Explained • Aliasing Ambiguity Exp...
• Understanding Aliasing in Digital Down Sampling • Understanding Aliasing...
• Sampling Discrete Time Signals: • Sampling Discrete Time...
• Decimation of Discrete Time Signals: • Decimation of Discrete...
• Interpolation of Discrete Time Signals: • Interpolation of Discr...
• Discrete Time Sampling Example: • Discrete Time Sampling...
• Typical Exam Question on Sampling • Typical Exam Question ...
For a full list of Videos and accompanying Summary Sheets, goto: www.iaincolling...
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[@tuongnguyen9391]

When I was a child, I used to look at the fan and awe by this but some how I cannot relate this phenomena to the Nyquist criteria or aliasing stuff. Thank you professor

[@iain_explains]

It's great to hear that my video has helped you understand something you've always wondered about. Curiosity is so important in life!

[@t-rexstudioproductions781]

It's an Optical Illusion An Aliasing Effect Due to the frame rate of the camera

[@iain_explains]

Yes, exactly. For more details, you can check out the videos listed in the description below the video, including: • How to Understand Aliasing in Digital Sampling kzbin.info/www/bejne/r2i4gISVlqtseZI • Aliasing Ambiguity Explained kzbin.info/www/bejne/sIaknJRqpNelgKM • Understanding Aliasing in Digital Down Sampling kzbin.info/www/bejne/mZLXcnymmq-teJY

[@stephensu4371]

Ws >= 2 * Winput 😏