P2_2 Big Ben 2: Enormous Benjamin

Abstract

The time-keeping ability of an analogue clock in the modern age relies heavily on the functioning of the motor. In this paper we ask: In the absence of a motor as the limiter, assuming some kind of ideal time keeping implement with the power to provide an arbitrarily large amount of torque, what would be the limits of the clock’s time-keeping abilities? We find the optimal material for such a construction to be beryllium and with calculations using the shear wave speed in this material we find a 4.4km length clock hand to be a reasonable upper limit to this clock’s abilities.