He said that if the fine-structure constant proves unstable, it would completely reshape modern physics. However, to uncover this, even the smallest possible changes in the constant must be measured with extreme precision. \u201cOur thorium atomic clock makes this possible for the first time,\u201d he disclosed.<\/p>\n
To test the assumption, the team turned to the nuclear clock<\/a>. Unlike traditional atomic clocks, which measure time based on the behavior of electrons orbiting an atom, a nuclear clock tracks energy transitions within the atomic nucleus.<\/p>\n The research team used a tiny crystal containing thorium atoms for the experiment. When the thorium nucleus switches between two different energy states, a ground state and a slightly more energetic excited state, it subtly changes shape.<\/p>\n This alters the way its electric field<\/a> is distributed. That minute shift, a quadrupole change, depends directly on the fine-structure constant.<\/p>\n \u201cWhen the atomic nucleus changes its state, its shape also changes, and with it its electric field,\u201d Schumm explained. \u201cIn particular, the quadrupole component of the field changes \u2013 this is a number that describes whether the shape of the electric field is more elongated, like a cigar, or more squashed, like a lentil.\u201d<\/p>\n Beyond keeping time<\/p>\n By precisely measuring this thorium transition, scientists aim to reveal whether the fine-structure constant remains constant or shifts slightly over time.<\/p>\n The thorium-containing crystals for the experiment were produced at the Vienna University of Technology, while the laser spectroscopy measurements were carried out in Boulder, Colorado.<\/p>\n \u201cWe were able to show that our method can detect variations in the fine-structure constant three orders of magnitude more precisely than previous methods, i.e., by a factor of six thousand,\u201d Schumm pointed out.<\/p>\n According to the team, the implications reach far beyond precision timekeeping. The thorium nuclear transition could enable physicists to explore previously inaccessible realms of new physics.<\/p>\n \u201cThis shows that the thorium transition we discovered can not only be used to build a new generation of high-precision clocks, but also allows research into new physics that was previously inaccessible experimentally,\u201d Schumm concluded in a press release<\/a>.<\/p>\n![\"\"](\"https:\/\/www.newsbeep.com\/nz\/wp-content\/uploads\/2025\/10\/A2_7656f6.png\" "\\"World\u2019s")
The nuclear clock.
Credit: Oliver Diekmann, TU Wien<\/a><\/p>\n![\"The](\"https:\/\/www.newsbeep.com\/nz\/wp-content\/uploads\/2025\/10\/A3_424f49.png\" "\\"World\u2019s")
The thorium crystals are about one millimeter in size.
Credit: Oliver Diekmann, TU Wien<\/a><\/p>\n