Were you fooled by our joke? The caesium fountain clock is being hosted by the ALPHA experiment at CERN’s Antimatter Factory, but not to redefine the second. The experiment is using it to take precise measurements of the spectra of antihydrogen.
We have all wished for one extra hour in the day. Now, this may become a reality, thanks to new measurements on the second from the BETA experiment at CERN’s Antimatter Factory. The experiment used the caesium fountain clock – one of the most precise clocks in the world, used to define SI units and help set coordinated universal time (UTC) – to precisely measure the second using caesium. In conjunction with this clock, BETA also used anticaesium atoms produced by the Antimatter Factory to compare the two definitions of the second given by matter and antimatter. By taking the average, scientists say that timekeeping can now be more accurate than ever before.
“It is about time we updated the definition of a second using antimatter,” says Dr Qui, spokesperson of the BETA experiment. “This way, several uncertainties cancel out, making the measurement much more precise.”
A brief history of timekeeping
More accurate methods to measure time have always been ticking along. Before the first clocks, humans relied on the geographical position of Earth’s rotation around its axis to determine time. The first clocks contained pendulums, which were also unreliable due to their damping. In 1932, the quartz clock was invented, which was much more accurate. However, the resonant frequency of quartz, which sends the electric signals to drive the clock, can change due to environmental factors. This makes them lose precision.
In 1967, the first atomic clock was invented. These are much more precise, because atoms from the same element will always have the same properties. The caesium atomic clock works by an oscillator sending a wave with a frequency of exactly 9 192 631 770 Hz (using the old second definition), which is the frequency needed to excite the caesium atoms. If the oscillator is incorrect, the non-excited atoms cause an electric signal to jolt the oscillator, creating a feedback loop to keep the clock running. An atomic clock will lose only one second in 138 million years.
BETA’s new measurement on anticaesium found its excitation frequency to be smaller than that of caesium: 8 499 682 790 oscillations of the oscillator were needed to excite its atoms. By taking the average of matter and antimatter, BETA scientists calculated the second to 8 846 157 280 oscillations: around 96% of the current definition. This means the day would last 24 hours, 56 minutes and 24 seconds. This would be rounded up to 25 hours during the week and rounded down during the weekend.
“We hope that this new measurement will make all our lives easier,” Qui continues. “Using antimatter, time will fly by more slowly.”
This measurement comes at a time when many countries are investigating the feasibility of a four-day working week. “Having an extra hour in the day means that a 40-hour work week can now be easily implemented, as well as a three-day weekend,” says Anita Chronon, from the HR department. “CERN staff will be trialling this new way of measuring time on Monday.”