# European physicists link optical clocks in a network and record Moon and Sun effect on clock rate

- Published: 2026-11-09 03:48 UTC
- Section: Science › Physics
- Tags: optical atomic clocks, gravitational potential, Moon and Sun gravity, clock network, optical fibre links, time dilation, arXiv preprint, groundwater monitoring
- URL: https://realtech.media/news/rt-efc463482c655a4047025888_european_physicists_link/

**Optical clocks joined by fibre lines registered periodic changes in Earth's gravitational potential caused by the Moon and Sun, the authors report on arXiv.**

![European physicists link optical clocks in a network and record Moon and Sun effect on clock rate](https://realtech.media/media/2026/11/06537394d2d76456.jpg)
*National Institute of Standards and Technology, Wikimedia Commons, Public domain*

European researchers used ultra-precise atomic clocks to record changes in the rate of time under the gravitational pull of the Moon and Sun, todaypress reports. The results of the experiment are published on the arXiv platform. [1]

An international group of physicists joined optical clocks into a single measurement network connected by optical fibre lines. According to the authors, the experiment detected extremely small periodic changes in Earth's gravitational potential. [1]

The researchers state that the attraction of the Moon and Sun causes oscillations comparable to a change in height of about ten centimetres. This leads to slight differences in clock rate at different points on the planet. [1]

The researchers say the technique could be used not only for ultra-precise time measurement but also for observing the movement of groundwater, changes in glaciers, tectonic activity and volcanoes. [1]

## Sources

1. [todaypress](https://todaypress.tv/ru/v-mire/luna-i-solnce-vliiaiut-na-xod-vremeni-na-zemle)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-efc463482c655a4047025888_european_physicists_link/