# Can differential friction explain a statue turning around?

Apparently in the Manchester museum, an Egyptian statue turns around while in a sealed display case. There is time-lapse footage of the statue, and in the article, Brian Cox is quoted as saying that:

Brian thinks it's differential friction, where two surfaces - the serpentine stone of the statuette and glass shelf it is on - cause a subtle vibration which is making the statuette turn.

Is that possible? Watching the video it seems that the statue doesn't have a constant rate of turning; it seems to turn only during the day, and it stops turning once it has completed a half-turn.

The only references to differential friction I could find were in the context of a moving vehicle braking when the left and right tyres were on different road surfaces, resulting in differential friction which could cause the car to swerve to one side. How can it function on a stationary object?

• Is this question about the differential friction explanation? Or is it about your alternative hypothesis? – user5582 Jun 24 '13 at 12:44
• Its about the differential friction explanation, since that's the notable claim. – Nick Jun 24 '13 at 12:49
• There doesn't seem to be any meaningful way we could answer this question. We can all chime in with our speculations (and it seems you, Professor Cox and I all have similar ideas), but what possible evidence could we provide to support it? – Oddthinking Jun 24 '13 at 14:20
• Nope, it's definitely ghosts. – SIMEL Jun 24 '13 at 20:12
• I don't know the name of the physical effect, but isn't it common knowledge that objects tend to rotate or move if they stand on a vibrating surface? If something causes the shelf to vibrate during day-time (people walking around, outside traffic, air conditioning equipment), wouldn't that explain the statue rotating? – Tor-Einar Jarnbjo Jun 25 '13 at 15:22