On May 1, 9:05=A0am, Crown-Horned Snorkack <chornedsnork...@[EMAIL PROTECTED]
>
wrote:
> Well, when was it?
>
> The actual length of sideric day, and of tropical day, increases
> slowly, as tidal friction irreversibly slows down the rotation of
> Earth.
>
This assumption and conclusion can be filed under astrology with a
touch of a geostationary Earth attached to it even though it is the
basis for much of the empirical approach to structural and timekeeping
astronomy.
A few weeks ago I posted an analogy between the maximum depth of
crust compared to the entire structure of Earth in terms of a bowling
ball and it amounts to less than 1 mm,the purpose being to show that
geodynamics of crustal evolution,motion and deformation may be linked
to geodynamics of the rotating interior.The average depth of the ocean
is just over 2 miles while the Earth's diameter is over 7 900 miles
across the Equator,I will not even bother to reduce it to a bowling
ball analogy.The point is that this 'tidal friction' business is the
product of minds who have yet to discover what geodynamics actually do
and especially the motion and deformation of the crust through
differential rotation.
> The actual length of sideric year can change - the energy of Earth=B4s
> orbit may change as energy is exchanged between orbital movement of
> Earth and other planets. But those changes are said to be minor. The
> changes in tropical year are likewise minor.
>
> The result is that the number of tropical days in a tropical year
> decreases.
>
> Sometime in palaeozoic, tidal rhytmites allegedly show that there were
> 400 days in a year.
>
> But the rate of tidal slowing is not constant. It changes with changes
> in the configuration of shelf seas and ocean basins. There would be
> major changes during ice ages, for example.
>
> The true duration of tropical year is around 365,2423 to 365,2424
> tropical days. Gregorian calendar requires 365,2425 days.
>
> The ***ulative error of Gregorian calendar through recent is thus less
> than two days.
>
> But how valid was Gregorian calendar in ice age?
Timekeeping astronomy is fairly intricate and especially the means by
which cl;ocks are kept in sync with the axial cycle at 24 hours/360
degrees.The correlation was constructed as inviolate meaning that it
does not directly refer to axial rotation directly let alone tying the
Earth's rotation directly to celestial sphere geometry (hence the
sidereral day ect).
If anybody decides to get serious about any part of timekeeping and
structural astronomy or the strong possibility that the geodynamics of
crustal motion may involve rotational geodynamics then let me know.
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