Due to the untidiness of the other thread (unintended repeated posting) I am creating an new one.

"AstroRockHunter wrote:
For your backward audience, could you please state the Equation of Time??? I'm not totally familiar with it.

Thanks.

Grey wrote; "I'm not oriel, of course, but here's a pretty straightforward site that gives a description of the issues involved in relating the sidereal day to the solar day. This is also an excellent site devoted to the equation of time"

The Equation of Time is not a formula but if you get it wrong and decide the rotation of the Earth is calculated off 23 hours 56 minutes instead of an equable 24 hours ( which the EoT reduces the unequal natural day to) you certainly can't do astronomy.

So now everyone is faced with a simple choice be they 'expert' or novice in that the Earth's rotation as determined by Foucault's pendulum completes one revolution in 24 hours while you determine that its rotation is tied to the stars or the sidereal motion of 23 hours 56 min.

Almost all the websites on Foucault's pendulum state that the rotation of the Earth on its axis is 24 hours per 360 degrees ,the history of the development of clocks,astronomy and geometry depend on it,

http://www.si.edu/resource/faq/nmah/pendulum.htm

http://www.abc.net.au/surf/pendulum/pendulum.htm




Grey,you can't figure the whole thing out,that much I know and I don't expect anyone else to,it is far too complicated and even unecessary if you press it far enough,but that is why I find the Albert's isolation of the motion of Mercury so very,very funny but you have to go to the relativity websites to know why this is so.

Of course the site has the Earth's rotation at 23 hours 56 minutes even though the pendulum only registers the Earth's axial rotation devoid of its orbital elliptical rotation.


http://www.phys.unsw.edu.au/PHYSICS_!/FOUCAULT_PENDULUM/foucault_pendulum.html

When Albert uses the "influence (!!!!) of the motion of the fixed stars" he is drawing on Mach who never understood what Newton meant by absolute/ relative time,space and motion in the first place,the easiest being Newton's framing of the EoT as the difference between absolute and relative time.All discernment of the motion of the primary planets was reduced to the equable day by astronomers in Newton's era and the EoT itself is a direct expression of Kepler's second law so when Newton works out his gravitational laws he is basing it on Kepler's planetary laws,that is why Albert is so funny when he attempts to paste Newton's law directly on to observation to come up with an ellipse.


I guess you have to understand the astronomical issues to know why the relativistic salesman is hilarious but it helps to know why basing observed planetary motions on 23 hrs 56 minutes instead of an equable 24 hours is an astronomical catastrophe.

Here is Albert's passage again with Mach's principle to send you on your way,again,I now don't think that you will have a good chuckle at it but a reasonable astronomer who knows his history should.


http://www.bun.kyoto-u.ac.jp/~suchii/mach.pr.html

"We must draw attention here to one of these deviations. According to Newton’s theory, a planet moves round the sun in an ellipse, which would permanently maintain its position with respect to the fixed stars, if we could disregard the motion of the fixed stars, themselves and the action of the other planets under consideration. Thus, if we correct the observed motion of the planets for these two influences, and if Newton’s theory be strictly correct, we ought to obtain for the orbit of the planet an ellipse, which is fixed with reference to the fixed stars" Albert's teletubby astronomy

Gr is elegant - funny,funny,funny !!!.