[time-nuts] Updating the unit of,time: the second.

[Dave B]

Hi.

This from the recent ShortWave Radiogram broadcast, may be of interest.

~ ~ ~

(Snipped stuff about other SI units undergoing a revamp...)

Scientists now have their sights set on updating the unit of
time: the second.

Currently, the second is defined by atomic clocks made of cesium
atoms. Those atoms absorb a certain frequency of light. The
wiggling of the light's electromagnetic waves functions like the
pendulum on a grandfather clock, rhythmically keeping time. One
second is defined as 9,192,631,770 oscillations of the light.

But a new generation of atomic clocks, known as optical atomic
clocks, outdo the cesium clocks. "Their performance is a lot
better than what currently defines the second," says physicist
Andrew Ludlow of the National Institute of Standards and
Technology in Boulder, Colo. Because those optical atomic clocks
operate at a higher frequency, their "ticks" are more closely
spaced, making them about 100 times more precise than cesium
clocks.

Ideally, the length of a second should be defined using the most
precise timepieces available. A switch might happen in the late
2020s, Ludlow says.

The change to the kilogram's definition was carefully
orchestrated so that it wouldn't affect normal people: A kilogram
of flour still makes the same number of biscuits. Any change to
the second will be similarly coordinated.

So, sorry, there'll be no chance to squeeze any extra seconds
into a day.

https://www.sciencenews.org/article/kilogram-just-got-revamp-unit-time-might-be-next

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So, perhaps a host of surplus cesium clocks on the market at some point?

73

Dave B G0WBX.

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