earth's tilt

On Friday, September 21, 2012 11:35:42 AM UTC-7, oriel36 wrote:


... The ancients in remote

antiquity,and I mean over 5000 years ago would have seen the

circumpolar stars still turn around Polaris as we see the same thing

today and that time scale is 20% into the great orbital cycle of the

precession of the equinoxes and not an axial trait as previously

believed.

This is just plain wrong, as are most facts in your epistles here...

http://earthsky.org/brightest-stars/...ast-north-star

Even 20% of "the great orbital cycle of the precession of the equinoxes" would move the pole far from Polaris... and of course the precession of the axis is an axial trait, what else could it be?

\Paul A

On Sep 21, 9:13*pm, Sam Wormley wrote:

* * * *Eventually I engaged, Gerald, trying to understand why he rants
* * * *and what might be the basis of his misunderstanding. His trouble
* * * *is rooted in the Anglican interpretation of the rotation of the
* * * *earth. Gerald regularly expresses his utter contempt and disgust
* * * *that we professors and teachers of astronomy note that the earth
* * * *rotates once, four minutes shy of 24 hours.

The equatorial circumference is found to be 24901 miles which makes
1037.5 miles for each 15 degrees of geographical separation.If you do
not accept that the Earth turns at a rate of 15 degrees/1037.5 miles
per hour then perhaps you can give the alternative values which
eventually are bounded within the 24901 mile circumference.I don't
express contempt for professors,they literally express contempt for
their students,astronomy and terrestrial sciences and common sense.

So,here we are in the 21st century trying unsuccessfully to explain
that the Earth turns once in 24 hours with each of these 24 hour days
keeping in step with each rotation without fail and if dismay is not
something that accompanies you day in and day out at such a huge loss
as this core fact,then we become less men much less astronomers or
teachers.







The effect can be
* * * *observed by anyone, that the stars rise in the east 4 minutes
* * * *earlier each night. School kids, using two sticks can sight any
* * * *prominent star in the nighttime sky two nights in a row and time
* * * *that the star lines up with the two sticks every 23h 56m and 4s.


It is not possible to explain the daily and orbital motion of the
Earth using circumpolar motion and a system based on the 24 hour day
formatted as 365 days/366 days for that is exactly what you are
looking at.



* * * *We notice that the sun appears to travel south in the winter and
* * * *back north in the summer. From a fixed perspective one can see
* * * *that the sun rises and sets at a different place along the horizon
* * * *everyday, changing most rapidly near equinoxes and coming to what
* * * *seems like a standstill at the solstices. And yet it moves!

* * * *Science is all about observation and experiment. We enhance our
* * * *understand of nature all around us, by taking the time to observe
* * * *and think, often needing little more than sticks, eyes, feet, and
* * * *brains plus a zest for learning and understanding.

On Sep 21, 9:52*pm, palsing wrote:
On Friday, September 21, 2012 11:35:42 AM UTC-7, oriel36 wrote:
... The ancients in remote

antiquity,and I mean over 5000 years ago would have seen the

circumpolar stars still turn around Polaris as we see the same thing

today and that time scale is 20% into the great orbital cycle of the

precession of the equinoxes and not an axial trait as previously

believed.

This is just plain wrong, as are most facts in your epistles here...

http://earthsky.org/brightest-stars/...ast-north-star

Even 20% of "the great orbital cycle of the precession of the equinoxes" would move the pole far from Polaris... and of course the precession of the axis is an axial trait, what else could it be?

\Paul A

Viewed from Mars,the Earth's polar coordinates will be seen to precess
360 degrees to the central Sun like so -

http://upload.wikimedia.org/wikipedi...precession.svg

It is no more than an observational certainty which matches other
planets in the solar system -

http://www.daviddarling.info/images/...gs_changes.jpg

If a person can't handle the annual orbital cycle,there is little
point moving on to greater orbital variations that are the precession
of the equinoxes.

On Sep 20, 7:32*pm, RichD wrote:
When and how did astronomers determine that the earth's axis
tilts from the ecliptic, and its value?

Well, long before anyone knew that the Earth orbited the Sun, or
rotated on its axis, they knew that the Sun's apparent path in the sky
was the Zodiac.

And that did not coincide with the Celestial Equator - the Zodiac was
a circle, but movement along it was in a different direction from the
apparent motion of the stars.

So the value of 23 1/2 degrees was known even in ancient Egypt and
Babylonia.

John Savard

On Friday, September 21, 2012 2:14:49 PM UTC-7, oriel36 wrote:

Viewed from Mars,the Earth's polar coordinates will be seen to precess

360 degrees to the central Sun like so -



http://upload.wikimedia.org/wikipedi...precession.svg


The problem, however, is that the graphic to which you refer above shows the 26,000-year motion of the Earth's axis WRT the fixed stars, and NOT the yearly motion of the Earth in its orbit. THIS is the definition of precession. During a single year the Earth's axial inclination changes every day WRT the sun, but currently remains aimed almost directly at Polaris.

It is no more than an observational certainty which matches other

planets in the solar system -



http://www.daviddarling.info/images/...gs_changes.jpg

I hope you understand that this series of photos only shows the changing aspect of Uranus as seen from Earth, because each planet is simultaneously moving WRT each other as they circle the sun at different rates. Uranus has its own "polar star" towards which its axis continually points.



If a person can't handle the annual orbital cycle,there is little

point moving on to greater orbital variations that are the precession

of the equinoxes.

Well, I would agree wholeheartedly with this statement.

On Sep 21, 3:58*pm, oriel36 wrote:
On Sep 21, 9:13*pm, Sam Wormley wrote:

* * * *Eventually I engaged, Gerald, trying to understand why he rants
* * * *and what might be the basis of his misunderstanding. His trouble
* * * *is rooted in the Anglican interpretation of the rotation of the
* * * *earth. Gerald regularly expresses his utter contempt and disgust
* * * *that we professors and teachers of astronomy note that the earth
* * * *rotates once, four minutes shy of 24 hours.

The equatorial circumference is found to be 24901 miles which makes
1037.5 miles for each 15 degrees of geographical separation.If you do
not accept that the Earth turns at a rate of 15 degrees/1037.5 miles
per *hour then perhaps you can give the alternative values which
eventually are bounded within the 24901 mile circumference.I don't
express contempt for professors,they literally express contempt for
their students,astronomy and terrestrial sciences and common sense.

So,here we are in the 21st century trying unsuccessfully to explain
that the Earth turns once in 24 hours with each of these 24 hour days
keeping in step with each rotation without fail and if dismay is not
something that accompanies you day in and day out at such a huge loss
as this core fact,then we become less men much less astronomers or
teachers.

The effect can be
* * * *observed by anyone, that the stars rise in the east 4 minutes
* * * *earlier each night. School kids, using two sticks can sight any
* * * *prominent star in the nighttime sky two nights in a row and time
* * * *that the star lines up with the two sticks every 23h 56m and 4s.

It is not possible to explain the daily and orbital motion of the
Earth using circumpolar motion and a system based on the 24 hour day
formatted as 365 days/366 days for that is exactly what you are
looking at.







* * * *We notice that the sun appears to travel south in the winter and
* * * *back north in the summer. From a fixed perspective one can see
* * * *that the sun rises and sets at a different place along the horizon
* * * *everyday, changing most rapidly near equinoxes and coming to what
* * * *seems like a standstill at the solstices. And yet it moves!

* * * *Science is all about observation and experiment. We enhance our
* * * *understand of nature all around us, by taking the time to observe
* * * *and think, often needing little more than sticks, eyes, feet, and
* * * *brains plus a zest for learning and understanding.

Here's goes nothin'. We could shorten the second by a fraction of
itself by .0077315 of; thereby, creating more "ticks" in a single day
to equal exactly 24 hours- not 23hrs., 56 mins, and 4 sec.. But...
what will this accomplish? 365.25 days in a year divided by 12 months
equals 30.4375 days to the month. How do we reconcile the perfect 24
hour day with each month and year?

On Sep 21, 7:29*pm, GogoJF wrote:
On Sep 21, 3:58*pm, oriel36 wrote:









On Sep 21, 9:13*pm, Sam Wormley wrote:

* * * *Eventually I engaged, Gerald, trying to understand why he rants
* * * *and what might be the basis of his misunderstanding. His trouble
* * * *is rooted in the Anglican interpretation of the rotation of the
* * * *earth. Gerald regularly expresses his utter contempt and disgust
* * * *that we professors and teachers of astronomy note that the earth
* * * *rotates once, four minutes shy of 24 hours.

The equatorial circumference is found to be 24901 miles which makes
1037.5 miles for each 15 degrees of geographical separation.If you do
not accept that the Earth turns at a rate of 15 degrees/1037.5 miles
per *hour then perhaps you can give the alternative values which
eventually are bounded within the 24901 mile circumference.I don't
express contempt for professors,they literally express contempt for
their students,astronomy and terrestrial sciences and common sense.

So,here we are in the 21st century trying unsuccessfully to explain
that the Earth turns once in 24 hours with each of these 24 hour days
keeping in step with each rotation without fail and if dismay is not
something that accompanies you day in and day out at such a huge loss
as this core fact,then we become less men much less astronomers or
teachers.

The effect can be
* * * *observed by anyone, that the stars rise in the east 4 minutes
* * * *earlier each night. School kids, using two sticks can sight any
* * * *prominent star in the nighttime sky two nights in a row and time
* * * *that the star lines up with the two sticks every 23h 56m and 4s.

It is not possible to explain the daily and orbital motion of the
Earth using circumpolar motion and a system based on the 24 hour day
formatted as 365 days/366 days for that is exactly what you are
looking at.

* * * *We notice that the sun appears to travel south in the winter and
* * * *back north in the summer. From a fixed perspective one can see
* * * *that the sun rises and sets at a different place along the horizon
* * * *everyday, changing most rapidly near equinoxes and coming to what
* * * *seems like a standstill at the solstices. And yet it moves!

* * * *Science is all about observation and experiment. We enhance our
* * * *understand of nature all around us, by taking the time to observe
* * * *and think, often needing little more than sticks, eyes, feet, and
* * * *brains plus a zest for learning and understanding.

Here's goes nothin'. *We could shorten the second by a fraction of
itself by .0077315 of; thereby, creating more "ticks" in a single day
to equal exactly 24 hours- not 23hrs., 56 mins, and 4 sec.. *But...
what will this accomplish? *365.25 days in a year divided by 12 months
equals 30.4375 days to the month. *How do we reconcile the perfect 24
hour day with each month and year?

Maybe the "second"naturally slows down and speeds up and we are not
aware of it.

On Sep 21, 8:01*pm, GogoJF wrote:
On Sep 21, 7:29*pm, GogoJF wrote:









On Sep 21, 3:58*pm, oriel36 wrote:

On Sep 21, 9:13*pm, Sam Wormley wrote:

* * * *Eventually I engaged, Gerald, trying to understand why he rants
* * * *and what might be the basis of his misunderstanding. His trouble
* * * *is rooted in the Anglican interpretation of the rotation of the
* * * *earth. Gerald regularly expresses his utter contempt and disgust
* * * *that we professors and teachers of astronomy note that the earth
* * * *rotates once, four minutes shy of 24 hours.

The equatorial circumference is found to be 24901 miles which makes
1037.5 miles for each 15 degrees of geographical separation.If you do
not accept that the Earth turns at a rate of 15 degrees/1037.5 miles
per *hour then perhaps you can give the alternative values which
eventually are bounded within the 24901 mile circumference.I don't
express contempt for professors,they literally express contempt for
their students,astronomy and terrestrial sciences and common sense.

So,here we are in the 21st century trying unsuccessfully to explain
that the Earth turns once in 24 hours with each of these 24 hour days
keeping in step with each rotation without fail and if dismay is not
something that accompanies you day in and day out at such a huge loss
as this core fact,then we become less men much less astronomers or
teachers.

The effect can be
* * * *observed by anyone, that the stars rise in the east 4 minutes
* * * *earlier each night. School kids, using two sticks can sight any
* * * *prominent star in the nighttime sky two nights in a row and time
* * * *that the star lines up with the two sticks every 23h 56m and 4s.

It is not possible to explain the daily and orbital motion of the
Earth using circumpolar motion and a system based on the 24 hour day
formatted as 365 days/366 days for that is exactly what you are
looking at.

* * * *We notice that the sun appears to travel south in the winter and
* * * *back north in the summer. From a fixed perspective one can see
* * * *that the sun rises and sets at a different place along the horizon
* * * *everyday, changing most rapidly near equinoxes and coming to what
* * * *seems like a standstill at the solstices. And yet it moves!

* * * *Science is all about observation and experiment. We enhance our
* * * *understand of nature all around us, by taking the time to observe
* * * *and think, often needing little more than sticks, eyes, feet, and
* * * *brains plus a zest for learning and understanding.

Here's goes nothin'. *We could shorten the second by a fraction of
itself by .0077315 of; thereby, creating more "ticks" in a single day
to equal exactly 24 hours- not 23hrs., 56 mins, and 4 sec.. *But...
what will this accomplish? *365.25 days in a year divided by 12 months
equals 30.4375 days to the month. *How do we reconcile the perfect 24
hour day with each month and year?

Maybe the "second"naturally slows down and speeds up and we are not
aware of it.

Why are we so damned determined to maintain that the duration of the
second stay the same throughout the year and time in general?

On Sep 22, 12:20*am, palsing wrote:
On Friday, September 21, 2012 2:14:49 PM UTC-7, oriel36 wrote:
Viewed from Mars,the Earth's polar coordinates will be seen to precess

360 degrees to the central Sun like so -

http://upload.wikimedia.org/wikipedi...precession.svg

The problem, however, is that the graphic to which you refer above shows the 26,000-year motion of the Earth's axis WRT the fixed stars, and NOT the yearly motion of the Earth in its orbit. THIS is the definition of precession. During a single year the Earth's axial inclination changes every day WRT the sun, but currently remains aimed almost directly at Polaris.


If you need convincing after looking at the sequence of images of
Uranus which clearly show a planet's polar coordinates,acting like a
beacon for a planet's orbital behavior,turn wrt to the central Sun
then you will have no difficulties accepting that this is what the
Earth's motion will look like from Mars or any other vantage point.Now
that you have discovered this single rotation of the polar coordinates
to the central Sun over the course of an annual orbit,when daily
rotation is added you have the variations in the natural noon cycle
along with a smoother explanation for the seasons.

So,the graphic demonstrates,under your own admission,that the polar
coordinates turn about an ecliptic axis and this is supported by
actual imaging -it takes only a simple imitation analogy and a broom
to complete the explanation that the precession of the equinoxes is an
orbital feature,not an axial one.







It is no more than an observational certainty which matches other

planets in the solar system -

http://www.daviddarling.info/images/...gs_changes.jpg

I hope you understand that this series of photos only shows the changing aspect of Uranus as seen from Earth, because each planet is simultaneously moving WRT each other as they circle the sun at different rates. Uranus has its own "polar star" towards which its axis continually points.


What can I do but chuckle at this given the distances of Earth to
Uranus and it can't be other than the polar coordinates actually do
change to the central Sun just as our own polar coordinates are now
turning through the circle of illumination at the equinox,same orbital
dynamics but different inclination .You are fine,if you feel it
necessary to reach a conclusion like that then continue being a
magnification enthusiast with pride as the type of interpretation
needed to make sense of those sequence of images is out of reach for
you and many others presently.








If a person can't handle the annual orbital cycle,there is little

point moving on to greater orbital variations that are the precession

of the equinoxes.

Well, I would agree wholeheartedly with this statement.

On Fri, 21 Sep 2012 16:11:17 -0700 (PDT), Quadibloc
wrote:
So the value of 23 1/2 degrees was known even in ancient Egypt and
Babylonia.

However, back then this value was somewhat more than 24 degrees
rather than the current 23.4 degrees.