Video reveals bizarre visual phenomenon

This video (QuickTime required), captured last week by fellow ScienceBlogger Tara Smith, demonstrates a rarely seen visual and auditory effect:

When you watch this video of me singing the Men Without Hats one-hit-wonder "Safety Dance," it appears as though can I neither dance nor carry a tune.

I wonder if any of our commenters can offer an explanation.

Perhaps of more interest to the scientific community: a first -- Greta and I are finally photographed with Professor Steve Steve!

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Yes, appearances can sometimes be deceiving... and then again, sometimes, not so much. :D

("One-hit wonder"! I doth protest!)

Obviously there is a wrinkle in the space-time continuum that distorts our perception of sight and sound. Just like when I sing and dance.

Glenn, you may be right. I had that whole album back in the 80s, and it had some pretty good songs. Living in China, Antarctica, I Got the Message, and so on, were all fun songs. But I'm pretty sure Safety Dance is the only one that made it on the charts.

I'm pretty sure it's something along the lines of the McGurk effect.

Yeah, the US Navy claims their new vomit ray uses electromagnetism to induce gastric distress, but that's all just to make it sound science-y. Now I know how the device really works.

I think that the two effects you noticed, out of tune and out of rhythm, can be created by the video camera used, which may create distortions in the audio recording and in the synchronization of audio and video streams. Low quality mics and a/d encoders create a shift of sound in the frequency domain, that affects especially the harmonics of complex sounds, giving the impression that you are out of tune.
The same encoder also causes a shift in time (a delay or an anticipation) of the auditory stream, which is the one primarily used for the perception of rhythm. As a consequence you appear to dance "with a delay". If you try to turn off the sound and tap the rhythm of dancing and than turn the sound back on you'll notice this asynchrony.

By Massimiliano Di Luca (not verified) on 22 Aug 2007 #permalink

Really funny. You're a good sport to post yourself singing the Safety Dance.