Gravitational effects on the LHC could be used to measure rain and snowfall

BBC : Gravitational forces introduce tiny but measurable fluctuations in the length of the Large Hadron Collider’s (LHC’s) 27 km circumference. The changes can be seen when the particle beams are calibrated to ensure they pass through the center of the ring’s vacuum chamber. Any shift in the beams’ position can be measured with micrometer accuracy. Those length fluctuations occur both daily and seasonally. The daily fluctuations are caused by normal tidal forces. Now one group of researchers investigating the fluctuations believes that the seasonal changes are caused by water from rain and snow, which accumulates during the winter and evaporates during the summer. Rolf Hut of Delft University of Technology, the Netherlands, and his colleagues found a correlation between the seasonal beam changes and local gravitational variations due to groundwater, as measured by NASA’s GRACE satellites. Because of the low resolution of the satellites and the short period of operation of the LHC, the correlation is not conclusive. But Hut says that if his team’s work is correct, then researchers could use the LHC as the world’s largest rain gauge.