Abstract

The Trinity Clock in Great Court is quite a prominent feature of the college, at least to look at. And it has a rather curious way of announcing the hours, once for Trinity and a second time for St John’s. It is always within a second or two of the correct time and yet it hardly ever requires adjustment. Does this mean that the mechanism is unaffected by the elements? What about temperature, pressure, humidity? And does the gravitational pull of the moon make any difference? The pendulum on the Trinity Clock has been instrumented to measure period and amplitude to great accuracy. The time is compared with UTC obtained from a GPS receiver. All of this data is streamed continuously to the web at http://www.trin.cam.ac.uk/clock/. If you thought that the physics of a pendulum was simple, then think again!