On Tuesday, October 10, 2017 at 11:00:23 PM UTC-6, Gerald Kelleher wrote:
nor by the recent upstarts who conjured up the idea that the Earth turned
once in 24 hours but only back in 1820.

You are just reading too much into an oversimplification.

The Earth turns once in 23 hours, 59 minutes, and 4 seconds... leading to
an average day-night cycle, when the Earth's rotation is combined with
its revolution around the Sun, that averages to 24 hours.

But that *average* was only _exactly_ 24 hours back in 1820, and now it's
a tiny fraction of a second longer.

If you use the metric atomic time definition of the second. Which you
need to, if you are wanting to consistently define the ohm, the henry,
the farad, and so on and so forth, so that the resonant frequency of
*this* inductance and *that* capacitance remains the same number of
cycles per second, even as the Earth slows down.

Leap seconds aren't due to anyone being "pretentious"; accurate
measurement of physical quantities is needed for making machines that
work.

John Savard