2025 One Hertz Challenge: Atomic Decay Clock is Accurate But Not Precise
1 min read
Summary
An individual named Alnwlsn has built a clock which measures time based on the rate of radioactive decay, which is also used to power the device.
The radioactive material used is common cooking salt, which has a half-life of roughly 600 years.
A microcontroller counts the decay particles using a Geiger-Müller tube, which are used to calculate elapsed time; after one year of continuous operation, the clock was just 26 minutes adrift.
While comparatively inaccurate to more established atomic clocks, the device’s novel approach makes it a worthy entry in the 2025 One Hertz Challenge.
Further details and the project’s status can be perused on Alnwlsn’s website.
