Skip to content
Bramble

Science

Teams in Vienna and Beijing build first working nuclear clocks

Two research teams, one in Vienna and one in Beijing, have built the first working nuclear clocks, described in two Nature papers. They do not yet beat the best atomic clocks, but the researchers expect rapid improvement.

2 outlets · 1L · 0C · 1R First reported Account updated
Image: ABC News (Australia)
Image: The Straits Times

1 / 2

The story, neutrally told

Mixed · 2Two teams of scientists working separately, one at TU Wien (Vienna University of Technology) in Austria and one in Beijing, have built the world's first two working nuclear clocks, according to two papers published in the journal Nature on 7 October. Mixed · 2Nuclear clocks keep time by tracking transitions inside an atom's nucleus rather than the electron transitions used in atomic clocks. They are not powered by nuclear fission or fusion. Mixed · 2Both clocks use thorium-229 in crystals, with lasers probing the nuclei. AFP says the crystals are solid-state calcium fluoride.

Mixed · 2The idea is that a nucleus is far smaller than the electron shell around it, so tracking its transitions could allow greater accuracy than current atomic clocks. Those clocks use elements such as caesium or strontium, and ABC reports they are approaching a physical limit on accuracy. Mixed · 2The new clocks do not yet outperform the best atomic clocks. Thorsten Schumm of TU Wien, who helped lead the Vienna team, said the clock is still "far from its target performance". Mixed · 2ABC reports that both clocks are accurate to about one second in 30 million years. AFP says the best conventional atomic clocks lose or gain only one second over billions of years.

Right · 1Shiqian Ding of Tsinghua University, who helped lead the Beijing team, said the two teams reached working clocks at the same time using different approaches, which shows the concept is robust. Schumm said the Vienna clock has better thorium crystals and the Beijing team a stronger laser, so combining them could give a significantly better clock. Mixed · 2Schumm says his team has worked towards a nuclear clock since 2008. ABC says a turning point came in early 2024, when the team used a laser to produce the predicted nuclear change, and Ding said no single step suddenly made the clock possible. Mixed · 2Proposed uses include satellite navigation, data-transfer synchronisation, surveying and metrology. ABC adds mining exploration, earthquake prediction and testing fundamental physics. Schumm envisions a chip-scale device, and AFP says nuclear clocks might be less bulky and delicate than atomic clocks.

Left · 1Victor Flambaum of the University of New South Wales, who was not involved in the studies, said nuclear clocks could become the "most accurate instrument humans have ever built" and that a "race" among other groups could soon produce one that beats atomic clocks. Mixed · 2The Vienna team used its clock in a proof-of-concept dark matter search. AFP says the experiment did not detect dark matter but the clock performed at the level of the best atomic clocks. ABC says the team used the clock to detect evidence of dark matter, so the two accounts differ. Schumm plans a second clock in Innsbruck within a year.

Every sentence links to the reporting it rests on. The pill in front of each says where its sources sit: Left, Centre or Right when one side supplies at least half of them, Mixed when they are evenly split. The number is how many outlets it cites.

Left1 outlet

Framing
ABC Australia presents an explainer on the promise of nuclear clocks, with a lede on 30 million years per second of accuracy, and leans on an outside expert.
Emphasis
Practical and scientific uses (GPS, mining, earthquake prediction, dark matter), the 'race' among research groups, and quotes from Flambaum, Schumm and Ding.
Leaves out or plays down
Does not say that the Vienna dark matter experiment found no dark matter, and does not give the accuracy of the best atomic clocks.
Charged language
“most accurate instrument humans have ever built”
For example
“Two teams of scientists have built the first working "nuclear clocks", which could become the world's most accurate timekeepers.” — ABC News (Australia)
“Professor Flambaum said there was a "race" among several other groups” — ABC News (Australia)

Centre0 outlets

No centre outlet in our sources has covered this story yet.

Right1 outlet

Framing
The Straits Times runs AFP's wire report as a straight news story about the two teams' achievement, with caveats on current performance.
Emphasis
The two teams' independent success, how nuclear clocks differ from atomic clocks, the fact that they are not yet better than atomic clocks, and the null dark matter result.
Leaves out or plays down
Omits mining and earthquake uses, the 2024 breakthrough and the Innsbruck plan.
For example
“Scientific teams working separately in Vienna and Beijing have developed the world’s first two operating nuclear clocks” — The Straits Times
“The experiment did not, in fact, detect dark matter” — The Straits Times