An international team of physicists has found that quantum collapse models, potentially linked to gravity, introduce a minuscule uncertainty in time itself. This sets a fundamental limit on clock precision, though far below current detection levels. The research, published in Physical Review Research, explores ties between quantum mechanics and gravity.
Researchers led by Nicola Bortolotti, a PhD student at the Enrico Fermi Museum and Research Centre in Rome, Italy, analyzed quantum collapse models including the Diósi-Penrose model and Continuous Spontaneous Localization. These models propose spontaneous wavefunction collapse without measurement, possibly connected to gravity. Their study establishes a quantitative link between one model and spacetime fluctuations caused by gravity, revealing inherent uncertainty in time measurement. Supported by the Foundational Questions Institute (FQxI), the work appears in Physical Review Research (2025; 7 (4)).Bortolotti explained the approach: “What we did was to take seriously the idea that collapse models may be linked to gravity. And then we asked a very concrete question: What does this imply for time itself?” The analysis shows this uncertainty imposes a limit on how precise clocks can be, but the effect remains negligible for technology. “The uncertainty is many orders of magnitude below anything we can currently measure, so it has no practical consequences for everyday timekeeping,” said team member Catalina Curceanu.Co-authors Kristian Piscicchia added: “Our results explicitly show that modern timekeeping technologies are entirely unaffected.” The findings highlight differences in how quantum mechanics treats time as a classical parameter versus general relativity's view of it bending with mass and energy. Curceanu stressed the value of such foundational research: “There are not many foundations in the world which are supporting research on these types of fundamental questions about the universe, space, time, and matter.”This offers a testable path to unify quantum physics with gravity, though no experiments have yet detected the predicted effects.