June 26, 2013 – An ancient Egyptian statue at the Manchester Museum in England is baffling museum workers: it appears to have started moving on its own and no one can figure out how!
The 3,800-year-old 25-centimetre (10-inch) statue of Neb-senu has been stored in a locked glass display case at the Manchester Museum for 80 years, but it only began to move very recently! It appears to rotate 180 degrees all on its own, turning its back against visitors.
After noticing it had strangely rotated one day museum curator Campbell Price placed it back in the correct position only to notice the next day that it had moved again. To figure out what was going on Price set up a time-lapse video to catch it moving over a period of one day. "Although the naked eye can't see it [moving], you can clearly see it rotate [in the video]."
Has the statue had enough of having people staring at it all day? Or does it want visitors to see the message asking for bread, beer, oxen, and fowl inscribed on its back?
Some experts believe that the statue is moving from very subtle vibrations caused by visitors' footsteps. Physicist Brian Cox thinks differential friction – a subtle vibration caused by the surface of the glass it's sitting on and the stone its base is made out – of is causing it to move. But Price doesn't think this theory is correct because the statue has been in the same place for 80 years and it had never rotated until recently.
Paul Doherty, senior scientist at the San Francisco's Exploratorium, believes that something called stick-slip friction is making it rotate. When the glass shelf it's on vibrates ever so sightly, from visitors' footsteps or, say, a passing train, the vibrating glass rotates the statue in the same direction, causing it to look like it's moving on its own.
An everyday example of stick-slip friction can be seen when someone uses an electric blender on a kitchen counter. The vibrations caused by the blender can make a nearby cup look like it's "walking" across the counter.
But why does it only rotate in a perfect semi-circle and stop once its back is facing visitors?
Doherty believes it only rotates 180 degrees because it is not evenly weighted. "One side of the statue has more weight than the other side. After turning around on the shelf, the statue's uneven bottom reaches a more stable position and stops turning," Doherty explained.
Do you think the statue is moving on its own, or that vibrations are the cause?