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Isolating the direction of the Earth's orbital motion



 
 
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  #11  
Old June 15th 04, 07:33 PM
Oriel36
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Default Isolating the direction of the Earth's orbital motion

Reed Riddle wrote in message ...

The Earth rotates in 23h 56m 4s with respect to the stars (and galaxies
and quasars). That is all that matters.


1 axial rotation through 360 degrees = 23 hours 56 min 04 sec

2 axial rotations through 360 degrees = 47 hours 52 min 08 sec

I assure anyone who checks using a stopwatch that it is a mathematical
and astronomical certainty that a star will NOT return to the same
position in the sky after 47 hours 52 min 08 sec (which corresponds to
2 sidereal days).

The conclusion is simple,Flamsteed's 1677 premise and method of proof
for determining the constant axial rotation of the Earth is incorrect.

[Mod. note: this is getting a little close to `because I say so'
speculation. Any more assertions that all modern observational
astronomy is wrong should perhaps be justified with argument -- mjh]
  #12  
Old June 15th 04, 07:34 PM
Jonathan Silverlight
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Default Isolating the direction of the Earth's orbital motion

In message , Oriel36
writes
I have requested an astronomer of distinction to handle a heliocentric
treatment of the material,despite the fact that it is not at all
difficult to determine the disasterous maneuvering of Flamsteed no
such astronomer has come forward.I cannot therefore be faulted for
taking it to a group of people who can handle the material which
predates the gravitational agenda of Newton and resolve the issue as
to why there exists dual rotation rates for the Earth and why the 23
hour 56 min 04 sec value and the method by which that value is
ascertained is incorrect.


Instead of flogging this dead horse any more, could you post Flamsteed's
text, instead of links to a simplified description of sidereal time and
an even more simplified picture of an elliptical orbit. Your links don't
mention him.
For the umpteenth time (Hah - my spell checker accepts that :-) the 23
hour 56 minute 04 second value is measured, and the 24 hour value is a
convention to allow days and hours of constant length.
I've been corrected as to whether Newton was writing about relativity
(and I'm rather disappointed !) but he did understand the Equation of
Time.

[Mod. note: quoted text trimmed -- mjh]

--
What have they got to hide? Release the Beagle 2 report.
Mail to jsilverlight AT merseia.fsnet.co.uk is welcome.
  #13  
Old June 17th 04, 08:40 PM
Oriel36
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Default Isolating the direction of the Earth's orbital motion

Jonathan Silverlight wrote in message ...
In message , Oriel36
writes
I have requested an astronomer of distinction to handle a heliocentric
treatment of the material,despite the fact that it is not at all
difficult to determine the disasterous maneuvering of Flamsteed no
such astronomer has come forward.I cannot therefore be faulted for
taking it to a group of people who can handle the material which
predates the gravitational agenda of Newton and resolve the issue as
to why there exists dual rotation rates for the Earth and why the 23
hour 56 min 04 sec value and the method by which that value is
ascertained is incorrect.


Instead of flogging this dead horse any more, could you post Flamsteed's
text, instead of links to a simplified description of sidereal time and
an even more simplified picture of an elliptical orbit. Your links don't
mention him.


Here is the basis of the Flamsteed's incorrect procedure.

http://www.burnley.gov.uk/towneley/tryall/eot1.htm




For the umpteenth time (Hah - my spell checker accepts that :-) the 23
hour 56 minute 04 second value is measured, and the 24 hour value is a
convention to allow days and hours of constant length.


It is required to determine the equable 24 hour day First in order to
determine the Earth's orbital period as 365 days 5 hours 49 min on
which the sidereal reasoning is based.

http://www.burnley.gov.uk/towneley/tryall/eot3.htm

Somehow you fail to comprehend that the assumption of constant axial
rotation through 360 degrees existed as the 24 hour/360 degree
equivalency centuries before Flamsteed,the principles of developing
accurate clocks for solving the Longitude problem are based on the 24
hour/360 degree longitude equivalency are based on the assumption of
constant axial rotation.

You cannot prove by direct observation that the Earth axially rotates
through 360 degrees in 24 hours,what you can do is assume constant
axial rotation and use the Equation of Time adjustment to equalise the
variations over the course of an annual orbit.

There are no 'leap' factors in the Equation of Time,it simply
facilitates the seamless transition from one 24 hour day to the next
by the appropriate addition and subtraction of minutes and seconds for
each axial rotation in order to maintain the 24 hour/360 degree
longitude equivalency.







I've been corrected as to whether Newton was writing about relativity
(and I'm rather disappointed !) but he did understand the Equation of
Time.

[Mod. note: quoted text trimmed -- mjh]


I have seen the correction and it is incorrect.Newton knew the
principles behind accurate clocks for solving the Longitude problem
and doubted that such an accurate mechanism could be constructed.The
benchmark for clock accuracy in Newton's era was the noon
determination and the Equation of Time application therefore the
principles which dictate constant axial rotation to the longitude
equivalency are permanently fixed to the geometry and geography of the
planet and its rotation

It was unethical of Flamsteed to piggyback on this already existing
assumption of constant axial rotation in accordance with the
principles of longitude and clocks.He transfers or rather hides an
axial rotational coordinate to an orbital .986 degree/3 min 56 sec
orbital coordinate,great if you wish to catalogue stars based on a
stellar circumpolar framework or condition celestial motion into the
civil calendar but ultimately destroys the work of Kepler and the
exquisite Equation of Time correlation between the natural unequal
day and the 24 hour clock day.

http://astrosun2.astro.cornell.edu/a...1/sidereal.htm

If you wish to adhere to Flamsteed's reasoning,the above graphic is an
astronomical justification of it.It is a poor choice.
  #14  
Old June 18th 04, 12:47 PM
Jonathan Silverlight
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Default Isolating the direction of the Earth's orbital motion

In message , Oriel36
writes

You cannot prove by direct observation that the Earth axially rotates
through 360 degrees in 24 hours,what you can do is assume constant
axial rotation and use the Equation of Time adjustment to equalise the
variations over the course of an annual orbit.


People measure the rotation of the Earth all the time, for many
different reasons and to a high degree of accuracy.
The name Foucault comes to mind, both for his pendulum and his naming of
the gyroscope. He'd probably have been fascinated by Gravity Probe B.
  #15  
Old June 23rd 04, 12:15 PM
Reed Riddle
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Default Isolating the direction of the Earth's orbital motion

In article ,
(Oriel36) wrote:

Reed Riddle wrote in message
...

The Earth rotates in 23h 56m 4s with respect to the stars (and galaxies
and quasars). That is all that matters.


1 axial rotation through 360 degrees = 23 hours 56 min 04 sec

2 axial rotations through 360 degrees = 47 hours 52 min 08 sec

I assure anyone who checks using a stopwatch that it is a mathematical
and astronomical certainty that a star will NOT return to the same
position in the sky after 47 hours 52 min 08 sec (which corresponds to
2 sidereal days).


If you want to take into account all the extra factors inherent in the
problem, then yep, things won't be exactly in the same place. At the
level of the usual consumer grade telescope, they will be, and that's
what we're talking about here.

The conclusion is simple,Flamsteed's 1677 premise and method of proof
for determining the constant axial rotation of the Earth is incorrect.


Do you realize all the effects of a non-constant rotation of the Earth?
Those would be far more prevalent than what you're worried about.....

[Mod. note: this is getting a little close to `because I say so'
speculation. Any more assertions that all modern observational
astronomy is wrong should perhaps be justified with argument -- mjh]


Well, I assert it's right.

Reed

--
Dr. Reed L. Riddle
Associate Director of Whole Earth Telescope Operations
Iowa State University Department of Physics & Astronomy
Email: drriddle "at" qwest.net
Homepage:
http://wet.physics.iastate.edu/~riddle/

"This life has been a test. If this had been an actual life, you would have
received instructions on where to go and what to do."
Angela Chase, "My so-called life"

Remove "DAMN SPAM" from my email address to reply.....
  #16  
Old June 25th 04, 10:40 PM
Arnie King
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Default Isolating the direction of the Earth's orbital motion

Jonathan Silverlight wrote in message ...

the 23 hour 56 minute 04 second value is measured, and the 24 hour value is a convention to allow days and hours of constant length.


The length of the mean solar day is measured to be 24 hours, and not
assigned by convention. If the mean solar day were significantly
different from 24 hours, then with respect to our good clocks that
repeat their indications every 24 hours, we would soon see the Sun
rising and setting at strange hours.

Of course, the mean solar day is not *exactly* 24 hours, i.e., 86400
seconds where the second is defined in terms of the frequency of a
certain atomic vibration. The difference is small, so that after
roughly 100 intervals of exactly 24 hours each, an angular discrepancy
corresponding to one second of time will have accrued ("leap second").

For the benefit of the original poster, the shortness of the sideral
day with respect to the mean solar day can be calculated by noting
that in a given amount of time, namely one year, the Earth makes
365.25 turns from the point of view of the Sun, and 366.25 turns from
the point of view of the distant stars. The extra turn in the stars'
viewpoint is the turn the Earth makes by orbiting the Sun. According
to the same effect, in one month the Moon makes one more turn in the
view of the stars than it does in the view of the Earth. (For a total
of one turn per month in the view of the stars: as all know, the Moon
makes zero turns per month in the view of the Earth because its
rotation has been stopped by tidal effects.) So, (3 min, 56 s per day)
x 366.25 days = 24.010 hours.

The "equation of time" referred to by the original poster is somewhat
unrelated. The amount of time from noon to noon, i.e., the solar day,
varries throughout the year. Somes days are shorter and some longer
than 24 hours, while 24 hours is the average taken over one year. The
discrepancy is as large as a few minutes. The variation is caused, in
roughly equal amounts, by the ellipticity of the Earth's orbit and the
inclination of the Earth's rotation axis with respect to the plane of
its orbit. These irregularities are taken into account by the equation
of time. Sundial readings, corrected with the equation of time, give
local mean time. With an additional adjustment for longitude (and
daylight savings time if it is in effect), sundial readings then agree
with the civil time kept by 24 hour, atomic-second clocks.

The amount of time from one meridian transit of a star to the next
transit of that star (this would be "noon" as defined by a star) shows
very little variation. So little as to be not possible to detect
directly until the advent of atomic clocks. With the greatest
regularity, this time is 23h 56m 4s.

If the Earth's axis were not inclined and its orbit not eccentric,
there would be no equation of time effect, but the solar day would
still be longer than the sideral day.

-Arnie
  #17  
Old June 27th 04, 12:08 PM
Oriel36
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Default Isolating the direction of the Earth's orbital motion

[Mod. note: this thread seems to be getting repetitive. Please
consider whether you have anything new to say before posting -- mjh]

(Arnie King) wrote in message ...

If the Earth's axis were not inclined and its orbit not eccentric,
there would be no equation of time effect, but the solar day would
still be longer than the sideral day.

-Arnie


This is incorrect in terms of the axial and orbital motions of the
Earth,the natural observational limitation dictate that these combined
motion can only be isolated seperately as assumptions and especially
in relation to the Sun.

The Earth's axial orientation and therefore its equatorial orientation
remains constant as a property of the Earth's axial rotation which is
independent of orbital motion .The time lapse image against Polaris
and stellar circumpolar motion adequately demonstrates this -

http://ottawa.rasc.ca/pictures/pdelorme/polaris.jpg

The erroneous justification of equatorial orientation or axial tilt
to the Sun as a component of the Equation of Time is taken by
observers who propose the analemma.

http://www.wengersundial.com/Analemma/analemma.jpg

As equatorial orientation remains constant as a property of axial
rotation,the error emerges from not considering that the Earth's
changing orbital orientation hence axial tilt does not cause the
daylight/darkness asymmetry but is a property of the Earth's orbital
position and that independent motion.Axial tilt in combination with
constant axial rotation cannot accelerate or retard the return of the
Earth axial longitude coordinates (assuming constant axial rotation)
back to the Sun/Earth line (noon) hence there is no justification in
incorporating it into the Equation of Time,as the analemmatic figure 8
or bottom line.



http://www.longwoodgardens.org/Sundial/Analemma.html

Orbital orientation as a consequence of independent orbital motion is
not at all difficult to gauge.It does not follow axial longitude
coordinates and represents the portion of the Earth orientated to the
Sun and the other portion generating an orbital shadow.The behavior of
this orientation and the division between daylight and shadow
correlates with Kepler's second law -

http://www.mhhe.com/physsci/astronom...ages/04f15.jpg

The effort to reduce all effects on the calculation of the equable 24
hour day to axial rotational coordinates comes at the expense of
ignoring the influences of orbital orientation notwitstanding that
everyone seems to bypass the Sun and the orbital motion of the Earth
altogether to achieve synchonicity with the axial rotational/stellar
circumpolar equivalency.
 




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