Re: Starmapping software
- From: "OG" <owen@xxxxxxxxxxxxxxxxxxx>
- Date: Sat, 30 Sep 2006 01:47:07 +0100
"oriel36" <geraldkelleher@xxxxxxxxx> wrote in message
news:1159446401.883857.161550@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
OG wrote:
"oriel36" <geraldkelleher@xxxxxxxxx> wrote in message
news:1159382942.492260.38450@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
The calendrical convenience of a 1461 day cycle broken up into 3 years
of 365 days and 1 year of 366 days was and remains a gorgeous human
achievement,so old that the further minor adjustments amounts to 10
days in 1582.As there is an alternate number of days every 4th year,it
should give you a clue that there are two systems involved,the first
governs the creation of the equable 24 hour day
There is no natural 'equable' 24 hour day.
I am delighted that you agree
So why do YOU talk about the 'equitable 24hd' as though it exists?
but it does not stop celestial sphere
geometers from referencing axial rotation to the Sun in 24 hours in
order to justify the return of a star to a meridian in 23 hours 56 min
04 sec -
YOU talk about the 'equitable 24 hours'. Proper astronomers know that the
measurable constant is the 23.56.04 stellar rotation.
http://astrosun2.astro.cornell.edu/academics/courses//astro201/images/sidereal_day.gif
There is no external reference for 24 hours
Correct. The exact 24 hour 'solar day' is an artificial construct.
and the axial rotation of
the Earth however there is an exquisite two step process which governs
the creation of the 24 hour day through the return of the Sun to noon
and the application of the Equation of Time correction.The genius was
the step taken by heliocentric astronomers in adapting the human
devised principle of the 24 hour day to the heliocentric assumption
that axial rotation is an independent and constant motion.No external
references were and are required to correlate the pace of a hand of a
clock with axial rotation at 15 degrees per hour and 24 hours /360
degrees in total.
You miss that that YOU have it wrong here.
Your 'hand of a clock' 24 hour clockwork clock is based on an AVERAGE 24
hours Solar meridiem. But, as you acknowledge in the url you linked to, if
it is 24 hours it isn't 360 degrees and vice versa. The full 24 hours
rotation of the Earth is 360.986 degrees as you point out.
and does not involve
the stellar background and secondly,the calendar extension which is
celestial sphere based but cannot be used to justify the Earth's axial
and orbital motions.
You need to explain yourself better here.
The return of a star to your geographical location in 23 hours 56 min
04 sec cannot,I repeat,cannot be explained using the axial and orbital
motions of the Earth.This is about as clear as it gets.
It is explained using the axial rotation. No problem there.
The mismatch of the calendar with the annual orbital motions which
required a 10 day correction should indicate that the human devised
principle for the equable 24 hour day ( Equation of Time correction)
and its wonderful extension where the Earth's annual orbit is
calculated using equable 24 hour days are two seperate systems.
Your prolixity militates against comprehensiblilty. You need to express
your
argument more clearly - address the audience, not yourself.
I do not mind these pseudo-authorative imperatives,it normally takes
one or two posts for them to show up but ultimately they are defensive
things which highlight the lack of technical competence in these
matters.
If you can't explain yourself, don't blame anyone else than yourself.
You are being educated here in a system you presently know little about
and it is well worth the effort to appreciate how the astronomical
correction which governs the creation of the 24 hour day and its
seamless transition from one 24 hour day to the next 24 hour day.It
also provides the basis for keeping the pace of a clock in sync with
axial rotation of `15 degrees per hour precisely.
I have been priviledged to witness how my astronomical ancestors
created the heliocentric adaption of the very old Equation of Time
system and would wish to see other astronomers come to admire it.
You are a fool if you think the Equation Of Time' is 'very old'. - What is
the earliest reference to it that YOU can find?
The heliocentric adaption of the equable 24 hour day to axial rotation
at the pace of a clock hand at 24 hours/360 degrees isolates axial
rotation without the need for any external reference.Orbital motion of
the Earth was isolated by Copernicus in his resolution for the motion
of the planets around the Sun -
http://antwrp.gsfc.nasa.gov/apod/image/0112/JuSa2000_tezel.gif
Nobody would have a problem recognising the faster Earth overtaking the
slower moving outer planets of Jupiter and Saturn thereby affirming the
planets orbit the Sun,on the same token there is never any need to
reference planetary motion to celestial sphere/calendrical geometry
otherwise the gorgeous insights of clocks/axial rotation and
retrogrades/heliocentricity would be destroyed.
What do you mean 'no need', if it aids comprehension and calculation the
need is self-evident. It does not rule out other means of expressing the
relationship - which seems to be your problem.
The Copernican reasoning for the orbital motion of the Earth and the
other planets around the Sun was waiting for contemporary aids such as
time lapse footage.The motions of Saturn and Jupiter are explained by
a faster moving Earth thereby planetary heliocentric motion is observed
directly from Earth.I have the luxury of clarifying this with the
images which reference the Earth's motions against the other planets -
http://antwrp.gsfc.nasa.gov/apod/image/0112/JuSa2000_tezel.gif
The stellar background which Newton introduced into heliocentric
reasoning does not aid appreciation of the images above and is
counter-productive to the point of being destructive -
"For to the earth planetary motions appear sometimes direct, sometimes
stationary, nay, and sometimes retrograde. But from the sun they are
always seen direct," NEWTON
The astronomical principles which keep axial rotation constant at 15
degrees per hour precisely also keep orbital motion seperate for the
purpose of explaining the observed motion of the planets.Newton's
attempt was to try and fit orbital geometry into the Ra/Dec system
which is why it can be now highlighted as the obvious and destructive
error in assigning the value of 23 hours 56 min 04 sec for axial
rotation and all the awful consequences spilling out from that.
The era of calendrical reform where 10 days was removed to bring the
calendar back in line with celestial sphere convenience demonstrates
that men can work together to correct things or adjust them to better
understanding of physical phenomena and data.A thorough astronomical
review is required to seperate the convenience of the calendar system
from actually justifying the Earth's motions using the calendar
system.It is not an easy task and made far more challenging in a
hostile enviroment which is based on the celestial sphere geometry of
the Ra/Dec system.
You really need to learn how to write more clearly. Try again. If it's
important to you, it's worth taking the effort to put your argument
clearly.
Not at all,you have the pleasure of trying to explain to others here
how you plan to fit a constant .986 degree orbital displacement into an
elliptical framework and still get Keplerian geometry -
I don't have any problem - because I don't foolishly think that a _constant_
0.986 degree displacement exists. I know that the Equation of Time means
that the difference between Universal Time and Mean Solar Time isn't
_constant_.
When you develop a distinct antipathy in seeing the Earth travel faster
around its orbital circumference the further it exists in distance from
the Sun and in direct conflict with Keplerian geometry then let me know.
Once again, your linguistic ability lets you down. Keep it simple and you
may be able to successfully say what you m
mean. I think (but you could be wrong) that you are proposing a state of
believing that "Earth travels faster around it's circumference when further
than the Sun" Do you think I currently think that I believe the above
stated relationship ? WHAT ON EARTH HAVE I SAID TO GIVE YOU SUCH AN
IMPRESSION ?
.
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