On Sunday, March 13, 2022 at 1:14:16 AM UTC-7,
kellehe...@gmail.com wrote:
The attempt to displace and the 24 hour system allied to the
Lat/Long system with RA/Dec must now be seen to have failed
really badly. It is possible to retain RA/Dec in the same category
as Timezones and the DST adjustment as useful additions to
the main timekeeping systems where natural noon and clock
noon keep roughly in step.
Natural noon and clock noon indeed keep "roughly in step". Why is that?
Well, the difference between the two is the Equation of Time.
Which I explain here
http://www.quadibloc.com/science/eot.htm
remember?
From the viewpoint of the man in the street, whether it is day-time or
night is important. The direction in which the Big Dipper is pointing
is not. So in _that_ sense you can indeed say that sidereal time or
stellar circumpolar motion is just something added on to the ordinary timekeeping system that tells us when to go to work or take our meals.
But you go further than that. You say the natural noon cycle is _genuinely_ fundamental. Professional astronomers *know* that isn't true.
They know that the Earth really is a big ball of rock, and so its rotational motion is uniform except when some force speeds it up or slows it down,
as seasonal variations in prevailing winds do very slightly. So slightly that until atomic clocks came along, stellar circumpolar motion, as measured
by transit circles, was directly useful in calibrating the most accurate pendulum clocks.
The sun's apparent motion in our sky is a _compound_ motion, the result
of _both_ the Earth's very nearly uniform physical rotation - which we
see directly in stellar circumpolar motion, with the period of 23 hours,
56 minutes, and 4 seconds - and the Earth's real orbital motion around the
Sun.
Add the two together, and you get the complicated apparent motion of the
Sun in our sky that gives us our daily natural noon cycle.
Those things are solid facts; they're natural consequences of living in a Sun-centered Solar System where the Earth's orbit is an ellipse, as found by Kepler. Newton refined and perfected the work of Copernicus, Galileo, and Kepler, finding the physical causes of the phenomena they observed, and removing the Sun-centred nature of our Solar System from all doubt.
Failed really badly? The only thing that's failed really badly is your attempt to argue otherwise, that somehow Newton made a mistake, and other
people made a mistake by following his wrong perspective. That notion isn't just wrong; it's laughable. It's laughable now, and it always will be.
It's true that not very many people can follow the mathematics used by
Adams and Le Verrier to predict the position of Neptune from discrepancies
in the motion of Uranus. That's hardly a pressing concern in everyday life.
But this was perhaps the crowning vindication of Newton's explanation of
the planets' motions in terms of the inverse-square law of gravity combined with the ordinary physical principles of the momentum of moving bodies.
And not very many people need to calculate a table of the Equation of Time
from first principles either. Once it's been done, someone using a sundial to tell time can just use such a table.
But just because things are removed from ordinary daily life doesn't make them untrue. Scientists need to peer behind surface appearances to see what is really true, to gain the fuller understanding of Nature that permits its manipulation
by technology.
Of course, there _are_ those who feel, with a considerable amount of justification, that we've done rather too much in the way of manipulating Nature
with our technology - so they might well favor them restricting themselves to an
"interpretive" approach, instead of going for prediction with the use of advanced
mathematics like calculus. But that's not because the approach they've been taking _doesn't work_; no, indeed.
Instead, the problem is that it works *all too well*, giving us the power to destroy our civilization and much of life on Earth with the atomic bomb and
its larger successor the hydrogen bomb.
John Savard
--- SoupGate-Win32 v1.05
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