Re: Climate change
- From: skyguy <skyguy@xxxxxxxxxxx>
- Date: Sat, 27 Jun 2009 05:14:46 GMT
oriel36 wrote:
On Jun 25, 11:05 pm, skyguy <sky...@xxxxxxxxxxx> wrote:
oriel36 wrote:
How hard is it (apart from the usual nuisances who reply) to determine
what role rotational inclination (tilt) actually plays and that it
does not cause the seasons ? .
The idea of 'no tilt/no seasons' is derived by a hypothesis from
Copernicus himself but the modified view replaces that view with
practical observations based on planetary comparisons where the cause
of the seasons is actually the orbital motion of the Earth and the
isolation of that motion and its characteristics.
If the earth had no rotational inclination (tilt), it's orbital motion
around the sun would *not* produce variable seasons. That's why a tilt
(to the orbital plane) is a necessary condition for seasons to occur.
Copernicus was right, no tilt-no seasons.
Oh brother,I could spend years answering every objection which seems
prepared to ignore the simple additional specific attached to orbital
motion which explains seasonal variations in daylight/darkness,why the
natural noon cycles vary,the seasonal disappearance of certain
constellations and all the other effects arising from the
modification.If you insist on the hypothesis of Copernicus of no tilt/
no seasons then you must be prepared to accept the full description
based on variable axial/Equatorial orientation to the central Sun -
No one is claiming that the orientation of the earth's axis varys with respect to the distant stars. It remains fixed towards Polaris. But it does vary in the way the axis is *presented* to the sun. This is caused solely by the earth's orbit of the sun and it produces all the effects which you enumerate (above), including the seasons.
"... the equator and the earth's axis must be understood to have a
variable inclination. For if they stayed at a constant angle, and were
affected exclusively by the motion of the center, no inequality of
days and nights would be observed. On the contrary, it would always be
either the longest or shortest day or the day of equal daylight and
darkness, or summer or winter, or whatever the character of the
season, it would remain identical and unchanged." Copernicus
Assuming your quote of Copernicus is accurate, his only error was the wording in the phrase 'the equator and the earth's axis must be understood to have a variable inclination'. He was certainly smart enough to know that the axis remains fixed in space relative to the stars. He was trying to make the point that the axis does vary in how it would be seen during the course of an earth year by an observer located at the center of the solar system.
The modified explanation alters the conception of 'no seasons' to
Equatorial conditions hence the degree of rotational inclination above
45 degrees indicate a planetary characteristic of Equatorial
conditions such as the Earth or below 45 degrees you have Uranus with
Polar characteristics.
So,the rotation of the Earth generates the day and night cycle and the
variations in the length of daylight/darkness is due to the orbital
motion which represents the seasonal cycle hence the seasons are not
caused by a daily rotational component such as 'tilt'.It is not the
difficult in this era when it is easy to make planetary comparisons.
Again, no one claims that the seasons are caused by (in your words) "a daily rotational component such as 'tilt'". There is no such thing. There is however a relative tilt between the earth's rotational axis (fixed towards Polaris) and it's orbital plane around the sun. It is this relative tilt which changes how the axis presents itself to the sun as the earth orbits the sun. Thus the seasons.
.
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