[geocentrism] Re: Fw: Celestial poles and Badastronomy
- From: Mike <mboyd@xxxxxxxxxxxx>
- To: geocentrism@xxxxxxxxxxxxx
- Date: Wed, 13 Oct 2004 22:39:05 +0100
Oops! sent this yesterday but from the wrong address.
Dr. Neville Jones wrote:
> No one is saying that the World's "axis" points at Polaris.
> It would point, by definition, at the north celestial pole (since we
> are referring to true north, rather than magnetic north).
So do you agree that the premise that the earth rotates is consistent
with Polaris's trace around the northern celestial pole?
> I'm not talking about the precession of the equinoxes, but
> the alleged change in axis orientation during the World's supposed
> 12-month orbit of the Sun.
Are you talking about nutation? This is the only other factor effecting
the direction of the earth's rotational axis that I can find and its
largest component has a period of 18.6 years. Could you supply a link
or reference to mainstream astromonists' claims that there is
"precessional motion of the World's axis, such that the World's north
pole always, rather miraculously, aligns itself with the north celestial
pole."
> There are several flaws in your simple analogy. If you fix
> your gaze on the distant mountain, then you will find that your head
> is slowly moving, such that your line of sight is travelling in the
> opposite sense to that of the train. If your gaze is not fixed, then
> the mountain will still move out of sight.
Maybe I didn't word it very well. When observing the distant mountian
keep your eyes, head, body etc. fixed relative to the train, the image
of the mountion will move very slowly across your retina.
> Next, we are not fixing
> our gaze on Polaris, but on the north celestial pole, which does not
> move in either system. Your analogy should therefore concern itself
> not with the mountain, but with the telegraph pole which apprently
> moves relative to the mountain.
Again, maybe I didn't word it well. My analogy assumed we had a fixed
direction of gaze relative to our frame (at right angles to the train,
or directly towards the celestial north pole in the sun orbiting earth
frame). The change in angle over time between the distant mountian and
our eye fixed to the frame on the tangentially moving train is very
small because of the distance of the mountian. The change in angle over
a year between Polaris and the eye of someone standing on the celestial
norh pole looking directly up is miniscule due to the huge distance
between us and Polaris.
> Next you claim that the mountain does
> not move when you look out of the window of the carriage, but does
> appear to move when you turn on the spot, yet in the first our gaze
> is to be "fixed" relative to the mountain and in the second it is to
> be "fixed" relative to our rotating body. This is where your simple
> analogy really falls apart. You cannot fix your gaze on the object in
> one, but on nothing in the other, because of course you will perceive
> different things.
As above, that's not what I meant. In reality we all know that if we
hold a digital camera up to the window of a car a distant mountain will
move slowly across the LCD all the time the car is going in a straight
line but will move very rapidly accross the LCD when the car turns.
Like all analogies this isn't perfect*, but it does encapsualate the
diffence between the parallax of Polaris over a year and the daily path
it traces around the northern celestial pole.
* To be a closer analogy the car should do a great big year-long
loop-de-loop while you point your camera (rotating about the direction
it is pointed, at 1 rev per day) at 66.5 degrees to the direction of the
car's motion. A distant mountain slightly off from 66.5 degress will
rotate daily around the centre of your picture when you play it back
while the distance from the centre of your picture to the mountain will
slowly change over the course of a year.
> In the "Celestial Poles" argument, the observer and his camera are
> ALWAYS fixed on the north celestial pole. If Polaris is so far away
> that on our journey around the Sun we notice only a parallax value of
> 0.01 arcseconds (I'm assuming that your figure is "correct," in the
> accepted system), then why, during our circling of the globe at our
> particular latitude, do we not observe something far less than 0.01
> arcseconds each sidereal day?
In the case of yearly parallax we are measuring the angle between
Polaris and the imaginary line extending directly up from the earth's
axis of rotation (which effectively doesn't change) and the distance we
move around the sun is very very very small compared to the distance to
Polaris, it is basic trigonometry that this angle doesn't change very much.
In the case of Polaris's daily path around the celestial north pole we
are measuring the apparent daily motion of Polaris due the fact that we
are rotating daily around an axis that doesn't quite point at it. The
*apparent* distance from Polaris to this point directly above the
northen celestial pole is directly proportional to the radius of the
path it traces and is why the stars further away from the pole describe
bigger circles as so beatifully demonstrated in the time lapse
photograph featured on your webpage regarding celestial poles.
> Remember, contrary to your simple
> analogy, we fix our eyes on exactly the same thing in both instances.
> Polaris (or the telegraph pole) either moves relative to the north
> celestial pole (or mountain), or it doesn't. It cannot move in one,
> but not the other - at least, not when they are this particular way
> round.
In shrot, my mountain was analogous to Polaris, my fixed gaze was
analogous to the northern celestial pole.
> I'm fairly outspoken on the website, so I can understand
> your use of the term, "misrepresentation." However, I do not seek to
> misrepresent anything.
Good, neither do I so one or more of us must be misunderstanding
something and if we stick to logical reasoning we must be able to come
to agreement on this issue.
Regards,
Mike.
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