In Vienna and Beijing, the First Nuclear Clocks Begin to Tick

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In Vienna and Beijing, the First Nuclear Clocks Begin to Tick

Researchers in Vienna and Beijing have independently developed the first nuclear clocks using thorium-229, achieving unprecedented timekeeping precision.

What: These clocks track oscillations in thorium nuclei rather than electron energy levels, losing only one second over millions of years. This precision potentially enables the detection of dark matter interactions through minute fluctuations in nuclear frequency.

Why it matters: This represents a jump from atomic to nuclear-scale precision in timekeeping, which may serve as a powerful new sensor for fundamental physics research.

Decoder

Thorium-229: An isotope capable of nuclear transitions that can be probed by lasers, the key to the new clock design.

Original article

Two independent teams in Vienna and Beijing have simultaneously built the first clocks that keep time by counting the squishing and unsquishing of the atomic nuclei of thorium. The clocks are so precise that they only lose one second once every few million years or so. Nuclear clocks have the ability to search for certain kinds of dark matter. If a particle of dark matter passes through the thorium nuclei, it could register as a wobble in the nuclear clock's otherwise steady tick-tock.

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