earth's tilt

In article ,
"Bast" wrote:

snip

Just like Galileo is often credited for claiming the earth went around the
sun.
His research was based on Copernicus's work, and who knows where Copernicus
got the idea.

I attended a lecture a couple of years ago that proposed the Persian
astronomer Qushji (*) as an important influence on Copernicus'
heliocentric theory, based on similarities between their mathematical
treatments & illustrations. The connection would have been made _via_ a
friend of Copernicus' who apparently brought some astronomical treatises
back from Baghdad. There were other important critics of the Ptolemaic
system in the mediaeval Islamic world, notably al-Tusi (1201-74 CE),
some of whose writings had become available to Western scholars by the
XV century.


*) See http://en.wikipedia.org/wiki/Ali_Qushji

--
Odysseus

"Quadibloc" wrote in message ...
On Sep 22, 4:56 am, Quadibloc wrote:
On Sep 21, 7:05 pm, GogoJF wrote:

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

Because the microhenry and the millifarad and the watt and the ampere
and the megohm are joined together, in part, by the second. If that
changed during the course of a year, how would we turn our radios to
the correct station?

In fact, this explains why we have "leap seconds", and why we
emphasize the "sidereal day" as the period of the Earth's rotation
instead of the solar day (which is affected by the Equation of Time).

We have chosen, as more useful and convenient, to define our units of
time, and practice the craft of timekeeping, so as to regulate our
machines first and foremost, and only secondarily, almost as an
afterthought, to keep track of the Sun and the daytime - since it
doesn't really matter if solar noon comes a few minutes late or early.

And this is what has Oriel so exercised. But then, he has told us that
he is a Christian, and so why should I be surprised that he objects to
what has been called a Faustian bargain - the one that led to the
"dark, Satanic mills" of the Industrial Revolution.

I don't think that our use of human ingenuity to make our lives easier
is wrong, but we have made mistakes in the course of it. But it was
our own ingenuity, not a bargain with a demon. And we are already
recognizing the need to respect the environment and make amends to
indigenous people.

Thus, I don't think that we have to worry about Diana and Mother
Nature getting together and destroying our present civilization... so
that we can spend 3,000 years balancing the cha (or possibly the
Dao?), as we turn into really cool people with big muscles, until a
great climactic confrontation comes by, and one Michael Levy comes to
help us with magical powers from an alternate reality...

John Savard


Quite poetic, Savard. The only flaw I see in your argument is that
mankind or divided subsets of the same will change his religion
faster than he’ll change the second. The Greek, Roman and Nordic
gods are long gone in Europe, the crusades over who controls
Jerusalem still live on with the base 60 numbering system of
minutes and seconds and degrees of the ancient copper age.
Rome destroyed the civilisation of Greece in the interests of
religion, promoting that psychotic Jew they nailed to a tree
as a deity. And this is a sample of what was destroyed.
http://en.wikipedia.org/wiki/Antikythera_mechanism
Rome’s power over plebeians like Kelleher still lives on in
Vatican City.
-- This message is brought to you from the keyboard of
Lord Androcles, Zeroth Earl of Medway

"Dr J R Stockton" wrote in message nvalid...
In sci.astro.amateur message , Thu, 20
Sep 2012 22:11:43, Davoud posted:


I don't have time to do the searching at the moment, but I have to
think that ancient natural philosophers, whether in Greece or Persia or
China or parts unknown, knew the extent of the Earth's axial tilt.

http://en.wikipedia.org/wiki/Earth%27s_Axis#History.


“Pytheas of Marseilles measured the shadow of a gnomon at the summer solstice�
What does the angle of the top of this standing stone in Scotland signify to
you, Stockton?
http://images.travelpod.com/tw_slide...ey-islands.jpg
A gnomon, perhaps?
http://en.wikipedia.org/wiki/Gnomon

The way to measure the angle of the Earth’s tilt is with a shadow,
and standing stones date to 3500 BCE. You went too far looking
to China.

-- This message is brought to you from the keyboard of
Lord Androcles, Zeroth Earl of Medway

On Sep 22, 8:02*pm, Dr J R Stockton
wrote:
In sci.astro.amateur message , Thu, 20
Sep 2012 22:11:43, Davoud posted:



I don't have time to do the searching at the moment, but I have to
think that ancient natural philosophers, whether in Greece or Persia or
China or parts unknown, knew the extent of the Earth's axial tilt.

http://en.wikipedia.org/wiki/Earth%27s_Axis#History.


I look at how they mangle the straightforward reasoning which connects
planetary shape with the motion and evolution of the surface crust
long after I proposed differential rotation as the key mechanism for
these planetary features.The uneven rotational gradient of the fluid
interior requires dropping the idea of the Earth as a celestial
gyroscope and picking up observations of celestial objects with
exposed rotating fluid compositions which display differential
rotation. The polar coordinates don't act like a gyroscope nor 'tilt'
towards and away from the Sun but rather are carried around in a
circle to the central Sun by the separate orbital motion of the
Earth,this leaves the researcher free to work with daily rotation and
the fluid interior rather than being too concerned about a fixed axis
- horses for courses in other words.

For an era so concerned with climate,it is amazing that they can't
describe the Earth's climate in planetary terms,in our planet's
case,it is largely equatorial as opposed to the polar climate of
Uranus by based on the angular distance between the the daily
rotational axis and the ecliptic axis.The Wiki article is more of the
same -

"The Earth's axis remains tilted in the same direction with reference
to the background stars throughout a year (throughout its entire
orbit). This means that one pole (and the associated hemisphere of the
Earth) will be directed away from the Sun at one side of the orbit,
and half an orbit later (half a year later) this pole will be directed
towards the Sun. This is the cause of the Earth's seasons."

http://en.wikipedia.org/wiki/Earth%27s_Axis#History

The cause of daylight/darkness asymmetries with greater fluctuations
towards the polar coordinates is due to the changing relationship of
rotational orientation of the planet to the circle of illumination.It
is so clearly demonstrated by the images of Uranus as the hemispheres
experience extreme fluctuations in daylight/darkness across large
areas of the planet that a thinking person can't but see that the old
idea of axial precession is an obstacle to recognizing the changing
orientation of the rotational axis to the central Sun.

I see these awkward 'tilted' explanations when it takes only a simple
imitation analogy to introduce another axis around which the polar
coordinates turn to the central Sun, a broom handle representing axial
'tilt' and the line of the body walking/orbiting a central object
representing an ecliptic axis goes a long way to accounting for the
observations of Uranus as the broom handle remains fixed to an
external point at all times as a person walks/orbits the object yet
the tilt of the broom will change to the central object/Sun as it
moves in a circle.

I wish somebody else would raise themselves to a higher standard,after
all,when you have all these guys running around announcing that the
sky is falling with climate,the same people have yet to replace the
old 'no tilt/no seasons' ideology with the new approach where a planet
falls between an equatorial and polar climate due to its inclination.






--
*(c) John Stockton, nr London, UK. *Mail via homepage. *Turnpike v6..05 *MIME.
* Web *http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms and links;
* Astro stuff via astron-1.htm, gravity0.htm ; quotings.htm, pascal.htm, etc.
*No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail News.

On Sat, 22 Sep 2012 11:30:50 -0700 (PDT), palsing
wrote:
OK, I could have said "all day, every day"... and I also could have
specified "nearly at Polaris"...

Which wouldn't be true. In some 12 000 years, the Eart's axis will
point near Vega instead, for example.

On Sat, 22 Sep 2012 14:27:51 -0700 (PDT), Quadibloc
wrote:
And this is what has Oriel so exercised. But then, he has told us
that
he is a Christian, and so why should I be surprised that he objects
to
what has been called a Faustian bargain - the one that led to the
"dark, Satanic mills" of the Industrial Revolution.

It's just weird that he uses the "dark Satanic mills", computers and
the Internet (both products of the industrial revolution) to
propagate his ideas....

On Sep 23, 8:56*am, Paul Schlyter wrote:
On Sat, 22 Sep 2012 14:27:51 -0700 (PDT), Quadibloc

wrote:
And this is what has Oriel so exercised. But then, he has told us
that
he is a Christian, and so why should I be surprised that he objects
to
what has been called a Faustian bargain - the one that led to the
"dark, Satanic mills" of the Industrial Revolution.

It's just weird that he uses the "dark Satanic mills", computers and
the Internet *(both products of the industrial revolution) to
propagate his ideas....

You are simply not good enough to make the distinction between
mechanical innovation as opposed to the great sciences which connect
astronomy to terrestrial sciences or solar system structure.Even when
timekeeping provided the resolution for measuring distances and
determining longitude on the surface of the planet,you are unable to
mesh the two in a belief that you can model planetary dynamics using
stellar circumpolar motion.Properly used,technological and mechanical
innovation is a brilliant aid to understanding astronomical and
terrestrial phenomena but unfortunately,as followers of Newton/
Flamsteed, your clockwork solar system based on Ra/Dec never worked.

William Blake understood the inhumanity and the cult ideologies that
bred it,the opportunistic attempt to hijack astronomy and apply
shortcuts and distortions for little more than intellectual pretense
but today it provides many of these followers with lifestyles and
reputations at the expense of the great astronomical heritage and the
wider community - an unthinking bunch who can't even keep one rotation
of the Earth in step with one 24 hour day -

"I turn my eyes to the Schools & Universities of Europe
And there behold the Loom of Locke whose Woof rages dire
Washd by the Water-wheels of Newton. black the cloth
In heavy wreathes folds over every Nation; cruel Works
Of many Wheels I view, wheel without wheel, with cogs tyrannic
Moving by compulsion each other: not as those in Eden: which
Wheel within Wheel in freedom revolve in harmony & peace."
Jerusalem

He was not the first nor the last to comment on the vicious strain of
empiricism that arose from trying to model planetary motions without
any care whatsoever and a conclusion plucked out of thin air.People
like Poe asked themselves how an accepted theory could answer so many
questions without even understanding where it came from but I assure
you and everyone else here than I know exactly where it came from and
why it is destructive in the extreme -

"To explain: — The Newtonian Gravity — a law of Nature — a law whose
existence as such no one out of Bedlam questions — a law whose
admission as such enables us to account for nine-tenths of the
Universal phænomena — a law which, merely because it does so enable us
to account for these phænomena, we are perfectly willing, without
reference to any other considerations, to admit, and cannot help
admitting, as a law — a law, nevertheless, of which neither the
principle nor the modus operandi of the principle, has ever yet been
traced by the human analysis — a law, in short, which, neither in its
detail nor in its generality, has been found susceptible of
explanation at all — is at length seen to be at every point thoroughly
explicable, provided we only yield our assent to —— what? To an
hypothesis? Why if an hypothesis — if the merest hypothesis — if an
hypothesis for whose assumption — as in the case of that pure
hypothesis the Newtonian law itself — no shadow of à priori reason
could be assigned — if an hypothesis, even so absolute as all this
implies, would enable us to perceive a principle for the Newtonian law
— would enable us to understand as satisfied, conditions so
miraculously — so ineffably complex and seemingly irreconcileable as
those involved in the relations of which Gravity tells us, — what
rational being could so expose his fatuity as to call even this
absolute hypothesis an hypothesis any longer — unless, indeed, he were
to persist in so calling it, with the understanding that he did so,
simply for the sake of consistency in words?" Allan Poe

The reasonable person accepts that technological innovation in all its
forms is separate to natural phenomena which links the celestial arena
with the terrestrial arena yet the vicious strain of empiricism tried
to muddy the distinction by asserting that mechanical experiments at a
human level are the same as dynamics art a planetary and solar system
level or the 'theory of gravity' as it is known.

The magnification enthusiasts have thrown their lot in with a bunch of
theorists who use the astronomical arena as a dumping ground for every
imaginative whim that enters their heads instead of using imaging to
clarify, and in some cases modify, the insights and methods of the
great astronomers.I have kept the issue of responsibility out of the
discussion as much as possible even though it looms in the background
as ultimately astronomy is an enjoyable pursuit in all its aspects and
only when it has come under an assault as it has from mathematical
theorists does responsibility to the past and the future enter the
picture.

I am proud of this era and its technological innovation and the
biggest user of imaging in this forum,what I am not proud of is the
utter contempt shown to astronomy and its relationship to terrestrial
sciences and it is not a popularity contest here,it is
talent,intelligence,effort,tenacity and all the better human traits
that will create the atmosphere for astronomy as an interpretative
science once more from a condition of unbridled speculative junk.

On Sep 23, 3:12*am, oriel36 wrote:
On Sep 22, 8:02*pm, Dr J R Stockton

wrote:
In sci.astro.amateur message , Thu, 20
Sep 2012 22:11:43, Davoud posted:

I don't have time to do the searching at the moment, but I have to
think that ancient natural philosophers, whether in Greece or Persia or
China or parts unknown, knew the extent of the Earth's axial tilt.

http://en.wikipedia.org/wiki/Earth%27s_Axis#History.

I look at how they mangle the straightforward reasoning which connects
planetary shape with the motion and evolution of the surface crust
long after I proposed differential rotation as the key mechanism for
these planetary features.The uneven rotational gradient of the fluid
interior requires dropping the idea of the Earth as a celestial
gyroscope *and picking up observations of celestial objects with
exposed rotating fluid compositions which display differential
rotation. The polar coordinates don't act like a gyroscope nor 'tilt'
towards and away from the Sun but rather are carried around in a
circle to the central Sun by the separate orbital motion of the
Earth,this leaves the researcher free to work with daily rotation and
the fluid interior rather than being too concerned about a fixed axis
- horses for courses in other words.

For an era so concerned with climate,it is amazing that they can't
describe the Earth's climate in planetary terms,in our planet's
case,it is largely equatorial as opposed to the polar climate of
Uranus by based on the angular distance between the the daily
rotational axis and the ecliptic axis.The Wiki article is more of the
same -

"The Earth's axis remains tilted in the same direction with reference
to the background stars throughout a year (throughout its entire
orbit). This means that one pole (and the associated hemisphere of the
Earth) will be directed away from the Sun at one side of the orbit,
and half an orbit later (half a year later) this pole will be directed
towards the Sun. This is the cause of the Earth's seasons."

http://en.wikipedia.org/wiki/Earth%27s_Axis#History

The cause of daylight/darkness asymmetries with greater fluctuations
towards the polar coordinates is due to the changing relationship of
rotational orientation of the planet to the circle of illumination.It
is so clearly demonstrated by the images of Uranus as the hemispheres
experience extreme fluctuations in daylight/darkness across large
areas *of the planet that a thinking person can't but see that the old
idea of axial precession is an obstacle to recognizing the changing
orientation of the rotational axis to the central Sun.

I see these awkward 'tilted' explanations when it takes only a simple
imitation analogy to introduce another axis around which the polar
coordinates turn to the central Sun, a broom handle representing axial
'tilt' and the line of the body walking/orbiting a central object
representing an ecliptic axis goes a long way to accounting for the
observations of Uranus as the broom handle remains fixed to an
external point at all times as a person walks/orbits the object yet
the tilt of the broom will change to the central object/Sun as it
moves in a circle.

I wish somebody else would raise themselves to a higher standard,after
all,when you have all these guys running around announcing that the
sky is falling with climate,the same people have yet to replace the
old 'no tilt/no seasons' ideology with the new approach where a planet
falls between an equatorial and polar climate due to its inclination.



--
*(c) John Stockton, nr London, UK. *Mail via homepage. *Turnpike v6.05 *MIME.
* Web *http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms and links;
* Astro stuff via astron-1.htm, gravity0.htm ; quotings.htm, pascal.htm, etc.
*No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail News.- Hide quoted text -

- Show quoted text -

Moon keeps tilt from wobbling.and with wobbling there would be no
humankind. TeBet

In sci.astro.amateur message
et, Sat, 22 Sep 2012 20:08:21, Paul Schlyter
posted:

On Sat, 22 Sep 2012 09:49:54 -0700 (PDT), palsing
wrote:
the Earth's axis points continuously at Polaris, 365/24/7.

...and what does 365/24/7 really mean? It ought to be either 365/24
(which leaves out the leap day) or 52/7/24 (which leaves out one day
each year, and also the leap day). Writing 365/24/7 is redundant.

Also, the Earth's axis does not point at Polaris, and is not likely to
do so within the lifetime of any of us. It does point continuously at a
slowly-moving point currently near Polaris, though.

--
(c) John Stockton, nr London, UK. Mail via homepage. Turnpike v6.05 MIME.
Web http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms and links;
Astro stuff via astron-1.htm, gravity0.htm ; quotings.htm, pascal.htm, etc.

On Sep 23, 3:44*am, oriel36 wrote:

The reasonable person accepts that technological innovation in all its
forms is separate to natural phenomena which links the celestial arena
with the terrestrial arena yet the vicious strain of empiricism tried
to muddy the distinction by asserting that mechanical experiments at a
human level are the same as dynamics art a planetary and solar system
level or the 'theory of gravity' as it is known.

Why would it be reasonable to accept the notion that the heavens work
by different laws than the Earth, when the laws of the Earth, applied
to the heavens, predict their motions with great accuracy?

John Savard