Posted by: Merlin PJ25 NOV 2009
Recently, Merlin took the opportunity to visit the Bowes Museum at Barnard Castle, Northumberland. One of the great attractions of this museum is its splendid pair of Canalettos, showing scenes on the Grand Canal in Venice in the 1730s.
Merlin sat for a while looking at these pictures — which are far too busy for just a glance — and also noted the other visitors who crossed in front of them. Almost all of them passed from left to right, so that they had travelled around the gallery in a clockwise fashion. Merlin realised that he, too, had walked clockwise in the galleries, and wondered why.
In the northern hemisphere, the sun travels from left to right as it goes from east to west. (Merlin knows that it is really Planet Earth turning!) So, on a sundial, the shadow of the gnomon will also travel in what we call a clockwise direction. Presumably this is the origin of the universal system whereby on a clock face the hands move in the same direction as the sun.
Many everyday activities involve a movement in a clockwise direction. Simply driving a screw into a piece of wood involves a clockwise turn of the screwdriver, as does the removal of a cork from a wine bottle.
In our early biology lessons we are taught that many biologically active polymers are coiled in an alpha-helix, which turns in a clockwise direction if one looks down the coil. Merlin wondered if it was this biological fact, and nothing to do with sun movements or corkscrews, that made people move in a clockwise direction around exhibitions and art galleries.
Certainly, in the case of the gallery with the Canalettos, it was nothing to do with the position of the door. This was in the centre of one wall so people had free choice of direction in which to move.
As a simple experiment, Merlin tried walking around the next gallery in an anticlockwise direction. To his surprise, it felt distinctly odd. Possibly, therefore, we are programmed in some way to do clockwise motions.
However, does this hold for left-handed people, or for those whose script, such as Arabic or Hebrew, reads from right to left?