How Church Bells are Cast

(Bells: physics and music cast in bronze)

Os sinos são instrumentos de percussão, da famı́lia dos idiófonos. São dispositivos de produção de som apenas aparentemente simples. O seu corpo é constitúıdo de uma liga metálica chamada bronze, que é uma combinação de cobre e estanho em proporções que podem sofrer ligeiras variações. No interior do sino encontra-se o badalo um pêndulo que, quando oscila, atinge o corpo fazendo com que o sino s...

Virtual Pitch and Pitch Shifts in Church Bells

It is well established that musical sounds comprising multiple partials with frequencies approximately in the ratio of small integers give rise to a strong sensation of pitch even if the lowest or fundamental partial is missing—the so-called virtual pitch effect. Experiments on thirty test subjects demonstrate that this virtual pitch is shifted significantly by changes in the spacing of the con...

Partial Frequencies and Chladni’s Law in Church Bells

The rim partials of a church bell (those with an antinode at the soundbow) generate the strike pitch or perceived note of the bell. The spacing in frequency of the higher rim partials has an important effect on the tonal quality of the bell. Investigations into the partial frequencies of 2752 bells, both bronze and steel, of a wide variety of dates, founders and sizes, show a simple and unexpec...

Food Taxes: How Likely Are Likely Effects?

A Review on Antibiotic Resistance: Alarm Bells are Ringing

Antibiotics are the 'wonder drugs' to combat microbes. For decades, multiple varieties of antibiotics have not only been used for therapeutic purposes but practiced prophylactically across other industries such as agriculture and animal husbandry. Uncertainty has arisen, as microbes have become resistant to common antibiotics while the host remains unaware that antibiotic resistance has emerged...