No. The lutetium clock announced by the National University of Singapore on 23 September 2026 has not changed the official definition of the second. That definition still uses a specified transition in caesium-133.
The university describes its clock as a precision advance and discusses a possible future redefinition. Independently, NIST's current reference states that the second is defined by fixing the caesium transition frequency at 9,192,631,770 hertz.
Building a better clock and adopting a new definition are separate steps. Optical-clock research can contribute evidence for a future standard, but announcing an experimental result does not itself replace the existing unit definition.
A new atomic clock does not automatically redefine time's basic unit. The official second remains based on caesium-133.
National University of Singapore
The university's September 2026 announcement presents optical clocks as candidates contributing to a redefinition expected in or after 2030, rather than reporting an adopted replacement.
Based on: National University of Singapore
National Institute of Standards and Technology
NIST's reference defines the second using the caesium-133 transition frequency fixed at 9,192,631,770 hertz. It does not define the unit using lutetium.
Based on: National Institute of Standards and Technology
Was this check helpful?
Sign in required
Sign in required
No. Goldfish can learn feeding schedules and spatial tasks. Experiments contradict a three-second memory limit, but do not establish one universal memory duration.
Yes. Researchers observed cell division at 63°C. Recovery after brief exposure to 70°C is a separate result and does not demonstrate reproduction at that temperature.
No. Bats have functional eyes and can see. Their visual abilities vary between species, so limited detail vision should not be confused with blindness.