Resumen de The sound of church bells: Tracking down the secret of a traditional arts and crafts trade

Patrik Vogt, Lutz Kasper, Jan-Philipp Burde

• The sound of church bells is part of most people's everyday life and can easily be examined with smartphones. Similar to other experiments of this column, we use a suitable iOS app. The underlying physical theory of church bells proves to be difficult. A reliable prediction of their natural frequencies based on their exact dimensions is only possible using the finite element method. If you ask bell founders how they calculate the rib of a bell (half longitudinal section of a bell, which completely determines the acoustic properties, Fig. 1) in order to get a church bell with the desired frequency spectrum, you will certainly not get an answer: the art of bell casting is based on centuries of experience and knowledge of the rib structure is only shared with direct descendants. We want to have a closer look at these well-guarded secrets, knowing full well that we cannot fully unravel them. This article presents simple mathematical models and a comparison with a data set of almost 700 bells.