Rotation speed
The Earth rotates on itself at a certain rate. This phenomenon determines the length of the day which varies constantly. This variation can be measured in microseconds. However, scientists have noted that the rotational velocity has been accelerating since the 1960s. Last June, our planet experienced its shortest day since records began. On June 29, the day was 1.59 milliseconds shorter than 24 hours. This phenomenon has repercussions on the instruments used to measure time, in particular the atomic clock.
Atomic clock
The international atomic clock is set by 400 atomic clocks around the world. UTC (Coordinated Universal Time) uses this measurement to determine the time for all 24 time zones. In addition, modern telecommunications systems need precise measurement to provide reliable data. However, when the Earth accelerates its course, the length of the day shortens. This means that the clock must adapt by subtracting time. Conversely, if the rotation slows down, more must be added. This slowdown is worrying.
Reverse trend
Scientists believe that our planet would rather follow a trend towards a slowing down of its rotation in the years to come. Thus, the days would be longer. If this scenario occurs, a negative leap second (addition of time) may be required.
internet at risk
Scientists are struggling to explain the phenomenon of variation in the Earth’s rotation. Several factors must be considered: climate, earthquakes, variations in the axis of rotation, tides, etc. Certainly, when the length of the day changes (astronomical clock), the atomic clock must adapt. Executives at several major information technology companies, including Meta, which owns Facebook and Instagram, are concerned that the added time will cause problems and affect the operation of servers. The issue will be debated at a conference to be held in 2023.
Sources : Timeanddate, The Conversation
