Said mrjesse: Well how can this be? First of all, as you know, Stellar Aberration, which is caused by the observer's transverse velocity, causes the apparent position of the object being observed to be ahead (in relation to the observer's direction) of where the object actually us. Remember, driving in the falling snow - the snowflakes appear to come from in front of you.replied LeGrande: That is an argument I gave you but you rejected it. I am glad to see you now trying to incorporate it, it gives me hope that you aren't entirely a lost cause : )
Said mrjesse: Thus, I maintain that the biggest source of apparent angular displacement of the sun for an observer on the earth is Stellar Aberration, and is about 20 arcseconds, and is due to the earth's transverse velocity of 67K mph as it orbits the sun.Replied LeGrande: Ahh, I have failed. >Legrande hangs his head in shame< Stellar Aberration has almost nothing to do with the Suns apparent position due to the Earths rotation. My dog Midnight is a pretty quick learner, maybe I should try and teach her some orbital mechanics : )
How about the apparent angular rate of displacement? I would agree with that.
You're saying that Stellar Aberration has almost nothing to do with the Earth's velocity? I think you're wrong on that one. WP says "At the instant of any observation of an object, the apparent position of the object is displaced from its true position by an amount which depends upon the transverse component of the velocity of the observer, with respect to the vector of the incoming beam of light." Are you saying that they're wrong? I mean they could be -- but is that what you're saying? this article also agrees with WP and even provides formulas which do not include the sun-earth distance. Stellar aberration is not influenced by the distance to earth from sun, but only by the observer's transverse velocity at the time of observation -- compared to the object being observed. Are you saying that these sources are wrong? There are lots more that agree with them. Are you saying they are all wrong?
No What I am saying is that you leave out the important part. What is important in stellar aberration is the DIRECTION the Earth is moving. It is going in opposite directions in the Fall and the Spring. Yes velocity is a factor but the DIRECTION is the critical part in Stellar Aberration. Do you know why the actual velocity of 500 thousand plus miles per hour isn't factored in? Repeat after me, 'frame of reference'.
"In the case of an observer on Earth, the direction of its velocity varies during the year as Earth revolves around the Sun and this in turn causes the apparent position of the object to vary. This particular effect is known as annual aberration or stellar aberration, because it causes the apparent position of a star to vary periodically over the course of a year. "
Basically use the driving in the snow example, knowing that you are driving in a circle, with the ground as your frame of reference. If the car was your sole frame of reference your correction factor would be different.
No, the falling rain was an argument that you gave for your alleged 2.1 degrees which you said was a function of the rate of earth's rotation of 2.1 degrees in the 8.3 minutes it took the sun's light to reach the earth. What I rejected was your allegations that Stellar Aberration caused a 2.1 degree apparent displacement, and that Stellar Aberration was affected by the distance to the light source.
First off, stellar aberration applies to Stars apparent position with respect to the Earths direction of velocity and has nothing to do with the Suns apparent position due to the rotation of the Earth. The Earths radial velocity correction is very small. It is simply a correction on another axis.
Sorry about that. It's just that when everything you say about something is contradictory to what I hold as common sense and contradictory to all the writings of scientists and when you're the only one in the whole wide world telling me something (that doesn't even make sense to begin with) along with your refusal to admit being wrong about things, yeah - it's hard for me to be convinced by what you say..
You can tell yourself that, but you aren't disagreeing anymore with the idea that things aren't where they appear to be. Initially you claimed that the Sun was exactly where it appeared to be. You no longer make that claim : ) Like I said before you are only squabbling over the amount of aberration.
In other words, if everyone at nasa knows about this phenomenon (as you have claimed)then there has got to be a name for it like "Such and such Aberration" or whatnot - but you refuse to tell me the name! You won't even tell me that you don't know the name. But for the love of pie -- tell us the name so we can go learn about it too!
I will let you in on a little secret : ) Everyone, except the Pope and Creationists like yourself, has used the Sun as the coordinate center since the time of Galileo. My example to you illustrates just one of the difficulties encountered if you use the Earth as the frame of reference.
To answer your question. Astronomers use the Sun as the Coordinate Center not the Earth. Finding Earth centric information is difficult because it is more trivia than anything else. Your Stellar Aberration is a good case in point, it shows the compensation that needs to be made because of the Earths orbit of the Sun.
After all of this, I have to ask you a simple yes or no question before we go on. Is the apparent position of the sun exactly the same as the Suns actual position to an observer on the Earth?