NavList:

   

Reply

Gary writes:

No, it accounts for the apparant movement of Polaris due to the
changing position of the earth's pole.
 If you look in the Almanac you
find that the positions of the stars change during the year.

Most of the change of coordinates of  the stars published in the
almanac
are not due to the stars' proper motions but are due to a change in
the
coordinate system used to define the stars' positions, a coordinate
system that changes with the earth's movement. The zero point of the
stellar coordinate system is the vernal equinox. Since the earth is
precessing and wobbling on its axis this zero point moves along with
it
making it appear that the stars have moved. Since the earth completes
on
cycle of precession every 26,000 years, the vernal equinox moves eight
tenths of a minute of arc every year and this accounts for most of the
changes seen in the stars' coordinates.



On Nov 22, 1:39 am, Isonomia  wrote:
> In other words, A2 accounts for the finite distance of the star! That
> is to say, the star wobbles with respect to the background galaxies
> (can't say stars because they are too near!!!)
>
> It is absolutely mind boggling to think that a handheld instrument
> like a sextant could possibly be affected by the distance to the
> stars.
>
> It completely turns history on its head. I've always been led to
> believe that astronomers looked at the stars as an end in itself - the
> great scientists pushing back the frontiers of knowledge  - knowledge
> for the sake of knowledge's sake!
>
> In fact, it seems to me that knowledge of the stars and motion of the
> planets was a necessary but fairly god-forsaken task mainly undertaken
> as a part of the production of accurate navigation tables.
>
> Engineers produced the equipment necessary to take the measurements,
> engineers then took the measurements and then some self-publicist
> scientist came along took what was already known by the engineers and
> gave it a grand title of the grand theory of space, etc. and claimed
> it was entirely his work!
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to NavList@fer3.com
To , send email to NavList-@fer3.com
-~----------~----~----~----~------~----~------~--~---

   

Reply