World’s First Nuclear Clocks Created

Scientists have created the world’s first nuclear clocks, which could help uncover new mysteries in physics. The two devices are described as a new generation of ultra-precise atomic clocks.

They measure time by using light to observe changes involving protons and neutrons inside the atomic nucleus. Atomic clocks are used for highly precise timekeeping and were first developed in 1949. Despite their name, they do not rely on nuclear fusion or fission.

Until now, the world’s most accurate clocks have been based on electrons transitioning between energy levels in atoms. The new clocks use thorium-229, a rare isotope whose nucleus can change its energy state when exposed to ultraviolet laser light. It is the only known nucleus with this property.

Scientists created a laser that emits ultraviolet light at a wavelength of 148.4 nanometers and directed it at small calcium fluoride crystals containing thorium-229.

The main achievement was the stable operation of the nuclear clocks. When locked to the thorium-229 nucleus, the laser maintained stable timekeeping and achieved an accuracy of about one part in a quadrillion (10⁻¹⁵) during the experiment.

Precise timekeeping is important for everyday technologies such as satellite-free navigation and telecommunications. Nuclear clocks could help make these systems even more accurate. According to the article, they may also play an important role in fundamental physics, although their exact future applications were not specified.