Good thinking Roger... > Of course it is a sundial, a very clever one. It does not > show regular hours but the original "stomach time". The > design is similar to Mass dials...
It does indeed share many of the properties of Mass dials but it is a good deal more colourful! The implicit hyperbola is upside down for the summer months but let's overlook that detail! For example, at 6a.m. the shadow of the nodus would be on the road a couple of blocks away! This nodus is the major novelty and I invite an enterprising diallist to exploit it. The double-arch M offers all kinds of possibilities... With a little mathematics and careful design one can arrange that the outer limbs of the M serve as error bars. The central limb indicates a specific time and the outer limbs bracket a range of times. I would fix it that there was a 68% chance of the local mean time falling within the indicated range. This corresponds to a well-known property of the normal distribution that there is a 68% chance of being within one standard deviation of the mean. It would be better to have the nodus parallel to the plane of the dial (rather than horizontal) to keep the shape of the shadow (almost) constant. We should be grateful to the McDonald's Ad Agency for pointing the way to some potentially useful theory! The only snag is that anyone who exploits this idea may fall foul of some U.S. patenting law! Frank King Cambridge, U.K. --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
