Oxford's Eternal Bell: Unraveling the mystery of its centuries-old battery

The Oxford Electric Bell has been running continuously since 1840. The secret to the longevity of this mechanism lies in its battery.

The bell, ringing continuously for over 184 years at the Clarendon Laboratory at the University of Oxford, is one of the world's longest-running scientific experiments. Known as the Oxford Electric Bell and emitting subtle sounds, it has fascinated scientists with its enduring operation since 1840. According to IFLScience, the key to its longevity is its extraordinary battery. However, the reasons behind the battery's prolonged lifespan remain a mystery.

Purchased by physicist Professor Robert Walker of Oxford University, the bell operates on so-called "dry piles" - an early version of the battery, which in this case, continuously powers the bell mechanism. Although the exact composition of the battery is still unknown, it is believed to be coated with sulphur, making it resemble a candle. Scientists have various theories about the composition and operation of the battery, but without direct access to its interior, these theories cannot be confirmed. Dr Robert Taylor, in a discussion with the BBC, highlighted the bell's exceptionally low energy consumption and minimal energy loss due to air resistance.

Despite its impressive longevity, the bell may soon stop ringing. Observations have shown that the ringing pace has significantly slowed over the last four decades. Taylor suggests that this could indicate the battery has only 5-10 years of life left. Eventually, every battery will run out, signalling the end of an experiment that has intrigued scientists and raised unanswered questions for years.

A Chinese company, Betavolt Technology, has developed a prototype of a miniature nuclear battery that could revolutionise how electronic devices are powered. Betavolt Technology uses a diamond semiconductor and a nickel isotope to work on a betavoltaic battery. This battery can operate in extreme temperatures and theoretically last for 50 years without discharging.

Currently, the BV100 battery prototype is in the development phase, but by 2025, Betavolt Technology plans to release batteries with a power of 1 W, which could ideally be linked together to power modern devices. This innovation would allow users to use devices without the need for charging them, potentially transforming mobile and wearable technology.