“The optical clock community is strongly motivated to obtain the best possible set of measurements before the SI second is ...

In every tick of the second, a specific transition of an electron of caesium-133 occurs 9192631770 times. This has become the yardstick of measuring time.

So doing the math, to measure one metre, all you have to do is measure the length of the path travelled by light in a vacuum during 9,192,631,770 / 299,792,458 radiations of a caesium-133 atom, or ...

In every tick of the second, a specific transition of an electron of caesium-133 occurs 9192631770 times. This has become the yardstick of measuring time.

There are two limitations in reducing this error: the technological challenges of measuring frequencies, especially higher ones; and the need to find a system – caesium-133 atoms for the second – with ...

With the aim of developing a cold cesium atom primary frequency standard, a cesium-133 magneto-optical trap (MOT) has been developed at CENAM's Time and Frequency Division. In this paper we present ...

Since 1967, when timekeepers officially forsook astronomy for physics as the basis of the second, the time’s definitional energy wave has been one that, when it hits a cesium-133 atom that is in ...

The world's first atomic clock was developed in 1949 using ammonia molecules, and an atomic clock using cesium-133 was put into practical use in the UK in 1955.

To do this, a high-powered laser light is trained on an atom of cesium-133, which subsequently excites its electrons into phasing between energy levels at exactly 9,192,631,770 vibrations over a ...

And in the middle of the twentieth century, the idea of the atomic clock was born. The atomic clock used in modern timekeeping uses lasers to manipulate atoms of cesium-133 along a frigid shaft.

The new iodine clock isn’t as accurate as an optical atomic clock in the laboratory, trading it off for mobility and robustness. But it is still accurate enough to lose or gain a second only ...

And the future of cesium-133 clocks themselves remains murky, especially as researchers develop and perfect even more reliable timekeepers like NIST’s experimental Ytterbium clock, a device that ...