Deep Thoughts

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Deep Thoughts
If the Earth rotated in the opposite
direction than it does now, what would happen to
the length of a day?
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Deep Thoughts
It the tilt of the Earth was only 5 instead
of 23.5, what would happen to the seasons?
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Deep Thoughts
If the tilt of the Earth was 90 instead of
23.5 and you are standing at the north pole,
describe a complete day/night cycle.
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Sacrobosco (Rome 1581)
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Precession There is a long term complication
when describing cycles in the sky! Cycles
themselves also have cycles that repeat. The
Earths rotational axis wobbles like a spinning
top, thus the orientation and direction the axis
points in the sky is continuously changing.
Precession produces a list of complications and
small fixes that need to be realized when
describing the cycles in the sky as time goes on.
A complete precessional cycle is nearly 26,000
years (a complete wobble), Earth's axis remains
at 23.5? while precessing.
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Consequences! Pole Star is temporary! (Polaris
now, Vega in about 13,000 years.)
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Consequences! Pole Star is temporary! (Polaris
now, Vega in about 13,000 years.) Seasons
Drift!! What? The seasons shift through calendar
over time! (Remember how astrologers froze the
sky 2000 years ago?! They didnt want to deal
with long term complications.) Orbital Sidereal
Year One complete orbit around the Sun
(365d,6h,9m,10s) Tropical Year (Year of
Seasons) Time between one vernal equinox and the
next vernal equinox. (365d,5h,48m,46s) RESULT
13,000 orbits 13000.5 seasonal cycles!