From Newsgroup: sci.astro.amateur

The Moon has an ecliptic South Pole, but as it does not also rotate like the Earth, it does not have a daily rotational South Pole. When they say a spacecraft will land at the Moon's South Pole today, they mean the ecliptic South Pole.
https://upload.wikimedia.org/.../6/61/AxialTiltObliquity.png
Only the unthinking following Newton believe the Moon also rotates as it runs its monthly circuit of the Earth. Walk around a central object with an outstretched arm pointing at the centre, and this imitates the Moon's motion of the Earth and why we see the same side.
"The Sun and the Earth rotate on their own axes. The purpose of this motion is to confer motion on the planets located around them; on the six primary planets in the case of the Sun, and the Moon in the case of the Earth. On the other hand, the Moon does not rotate on the axis of its own body, as its spots prove " Kepler
Astronomy was taken over by mathematical theorists in the 17th century, so society today inherits stupid notions like a rotating Moon despite the fact we see the same side from the surface of a rotating Earth and its orbital motion.
It disrupts appreciation of the phases, including the dark phase (New Moon), and the motion of the Moon behind the Sun and its glare monthly and at a solar eclipse. The Neolithic people could appreciate celestial objects lost to the glare of the Sun periodically and it is hoped that eventually contemporaries do the same.
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From Newsgroup: sci.astro.amateur

Briefly, the Moon acts like a car travelling around a traffic roundabout where the same side always faces the centre as a property of its orbital motion. Call it revolution.

There was a purpose in introducing Kepler's perspective on a non-rotating yet orbiting Moon as his Somnium work lends itself to misinterpretation on that account. His revolution is orbital motion and uses the poles of the ecliptic, which the Earth also has, as inferred by the ecliptic plane.

https://books.google.ie/books?id=OdCJAS0eQ64C&pg=PA80&lpg#v=onepage&q&f=false

The RA/Dec framework tries to dispense with the ecliptic poles and tries to gauge everything off the daily rotational characteristics on the Earth like so.

https://www.youtube.com/watch?v=WvXTUcYVXzI&t=104s

Contributors here should already see there are complex issues involved, and the least of them all is a discussion on the Moon's orbital motion of the Earth. The first Sun-centred astronomers worked off the ecliptic plane and poles rather than the clockwork solar system, which works off RA/Dec conceptions.

"The third movement is the declination movement. For the axis of daily rotation is not parallel to the axis of the great circle but is inclined to it by such a part of the circumference, which in our time is almost 23 and a half degrees. Thus, the Earth's centre always remains in the plane of the ecliptic, i.e. on the circumference of a great circle, and its poles revolve, drawing small circles on both sides around the centres equidistant from the axis of the great circle. This movement, too, takes place over almost a year and is almost equal to the revolution of the great wheel" Copernicus, Commentariolus.
All this becomes important when dealing with Kepler's representation of Mars over sixteen years and, once again, misinterpreted by a mathematician. It does involve what is called frames of reference in modern terminology.

https://en.wikipedia.org/wiki/Johannes_Kepler#/media/File:Kepler_Mars_retrograde.jpg


[ I imagined this would not be posted to Google Groups given that this discussion group is meant to be frozen in time.]
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From Newsgroup: sci.astro.amateur

Your last post to Google Groups is just as ignorant as was your first.

You remain clueless, Gerald.
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From Newsgroup: sci.astro.amateur

On Thu, 22 Feb 2024 11:14:32 +0000, oriel36 wrote:

Briefly, the Moon acts like a car travelling around a traffic
roundabout where the same side always faces the centre as a
property of its orbital motion. Call it revolution.

Yes, that's true.

So the Moon revolves around the Earth, with the D'Alembert
Mountains in the front, and Mare Smithii in the back.

A car in a traffic circle is normally always facing forwards,
so that the driver can see where he (or she) is going.

And the Apollo Command Module, as it orbited the Moon, also
was facing forwards in its orbit.

Normally, we don't call either of those things rotation.

A car might spin out of control on an icy road, but when
it's facing forwards in the direction it is being driven,
it is not thought of as spinning, even if the car is turning,
or going around in a circle.

So why do we say the Moon rotates, when its orientation is
constant with respect to its orbital motion? That is a fair
question to ask.

However, that question _does_ have an answer, and it has been
presented to you a number of times.

Part of the answer is simply the fact that the Moon doesn't
have rocket engines coming out of Mare Smithii; nobody is
driving it, it isn't being propelled in a forward direction
or directed by someone piloting it.

That in itself doesn't account for the distinction, but it
makes an alternate way of looking at the Moon's motion
possible.

What really leads to astronomers preferring to gauge the Moon's
rotation in terms of the fixed stars instead of in terms of the
Moon's orbital motion is the fact that the Moon's orientation
does *not* precisely follow the Moon's orbital motion.

Instead, it exhibits a phenomenon known as _libration_. It wiggles
a bit, sometimes showing a bit extra of itself on the left,
and sometimes a bit extra of itself on the right, as viewed from
Earth.

And when astronomers calculated the Moon's motions, what they found
was that the libration was equal to the difference between the Moon's
orbital motion - which, as per Kepler, follows an *elliptical* path,
sweeping out equal areas in equal times, _not_ a perfectly circular
orbit at constant speed - and a _uniform_ rotation of the Moon, which
matches the orbit in its period, but which, unlike the orbit, is
constant and uniform when measured relative to the fixed stars.

So for purposes of calculating the Moon's position and orientation,
treating the Moon as having a rotation independent of its motion just
makes things simpler; that motion is constant, and leaves out all the
variation in its orbital motion, so that variation is only counted
*once*, not two or three times, in the calculation.

This isn't following Newton without thinking. Astronomers know
exactly what they're doing.

John Savard
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From Newsgroup: sci.astro.amateur

Quadibloc wrote:

On Thu, 22 Feb 2024 11:14:32 +0000, oriel36 wrote:

Briefly, the Moon acts like a car travelling around a traffic
roundabout where the same side always faces the centre as a
property of its orbital motion. Call it revolution.

Yes, that's true.

So the Moon revolves around the Earth, with the D'Alembert
Mountains in the front, and Mare Smithii in the back.

A car in a traffic circle is normally always facing forwards,
so that the driver can see where he (or she) is going.

And the Apollo Command Module, as it orbited the Moon, also
was facing forwards in its orbit.

Normally, we don't call either of those things rotation.

A car might spin out of control on an icy road, but when
it's facing forwards in the direction it is being driven,
it is not thought of as spinning, even if the car is turning,
or going around in a circle.

So why do we say the Moon rotates, when its orientation is
constant with respect to its orbital motion? That is a fair
question to ask.

However, that question _does_ have an answer, and it has been
presented to you a number of times.

Part of the answer is simply the fact that the Moon doesn't
have rocket engines coming out of Mare Smithii; nobody is
driving it, it isn't being propelled in a forward direction
or directed by someone piloting it.

That in itself doesn't account for the distinction, but it
makes an alternate way of looking at the Moon's motion
possible.

What really leads to astronomers preferring to gauge the Moon's
rotation in terms of the fixed stars instead of in terms of the
Moon's orbital motion is the fact that the Moon's orientation
does *not* precisely follow the Moon's orbital motion.

Instead, it exhibits a phenomenon known as _libration_. It wiggles
a bit, sometimes showing a bit extra of itself on the left,
and sometimes a bit extra of itself on the right, as viewed from
Earth.

And when astronomers calculated the Moon's motions, what they found
was that the libration was equal to the difference between the Moon's
orbital motion - which, as per Kepler, follows an *elliptical* path,
sweeping out equal areas in equal times, _not_ a perfectly circular
orbit at constant speed - and a _uniform_ rotation of the Moon, which
matches the orbit in its period, but which, unlike the orbit, is
constant and uniform when measured relative to the fixed stars.

So for purposes of calculating the Moon's position and orientation,
treating the Moon as having a rotation independent of its motion just
makes things simpler; that motion is constant, and leaves out all the variation in its orbital motion, so that variation is only counted
*once*, not two or three times, in the calculation.

This isn't following Newton without thinking. Astronomers know
exactly what they're doing.

John Savard

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From Newsgroup: sci.astro.amateur

Quadibloc wrote:

On Thu, 22 Feb 2024 11:14:32 +0000, oriel36 wrote:

Briefly, the Moon acts like a car travelling around a traffic
roundabout where the same side always faces the centre as a
property of its orbital motion. Call it revolution.

Yes, that's true.

So the Moon revolves around the Earth, with the D'Alembert
Mountains in the front, and Mare Smithii in the back.

A car in a traffic circle is normally always facing forwards,
so that the driver can see where he (or she) is going.

And the Apollo Command Module, as it orbited the Moon, also
was facing forwards in its orbit.

Normally, we don't call either of those things rotation.

A car might spin out of control on an icy road, but when
it's facing forwards in the direction it is being driven,
it is not thought of as spinning, even if the car is turning,
or going around in a circle.

So why do we say the Moon rotates, when its orientation is
constant with respect to its orbital motion? That is a fair
question to ask.

However, that question _does_ have an answer, and it has been
presented to you a number of times.

Part of the answer is simply the fact that the Moon doesn't
have rocket engines coming out of Mare Smithii; nobody is
driving it, it isn't being propelled in a forward direction
or directed by someone piloting it.

That in itself doesn't account for the distinction, but it
makes an alternate way of looking at the Moon's motion
possible.

What really leads to astronomers preferring to gauge the Moon's
rotation in terms of the fixed stars instead of in terms of the
Moon's orbital motion is the fact that the Moon's orientation
does *not* precisely follow the Moon's orbital motion.

Instead, it exhibits a phenomenon known as _libration_. It wiggles
a bit, sometimes showing a bit extra of itself on the left,
and sometimes a bit extra of itself on the right, as viewed from
Earth.

And when astronomers calculated the Moon's motions, what they found
was that the libration was equal to the difference between the Moon's
orbital motion - which, as per Kepler, follows an *elliptical* path,
sweeping out equal areas in equal times, _not_ a perfectly circular
orbit at constant speed - and a _uniform_ rotation of the Moon, which
matches the orbit in its period, but which, unlike the orbit, is
constant and uniform when measured relative to the fixed stars.

So for purposes of calculating the Moon's position and orientation,
treating the Moon as having a rotation independent of its motion just
makes things simpler; that motion is constant, and leaves out all the variation in its orbital motion, so that variation is only counted
*once*, not two or three times, in the calculation.

This isn't following Newton without thinking. Astronomers know
exactly what they're doing.

John Savard

Also, if you were to be living on the far side of the moon you would never see the Earth, but you *would* see the Sun rise and set about every 29.53 days, which is a pretty good indication that it is indeed rotating on its axis.
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From Newsgroup: sci.astro.amateur

On Fri, 23 Feb 2024 03:05:34 +0000, palsing wrote:

Your last post to Google Groups is just as ignorant as was your first.

I'm afraid that you won't be rid of him that easily.

The post to which you replied wasn't made from Google Groups.

The Pan newsreader that I use with Eternal September displays the
"User Agent" field with each post. In the case of these recent
posts of his, the User Agent is "Rocksolid Light", which means
he took the advice of a poster here, and went to

https://news.novabbs.com/

to access Usenet via a web interface, for an experience not too
radically different from that provided by Google Groups.

John Savard
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From Newsgroup: sci.astro.amateur

On Fri, 23 Feb 2024 23:35:24 +0000, palsing wrote:

Also, if you were to be living on the far side of
the moon you would never see the Earth, but you
*would* see the Sun rise and set about every 29.53
days, which is a pretty good indication that it is
indeed rotating on its axis.

That's true, but he already _knows_ that this does
happen. He doesn't view that as "proving" that the
Moon rotates, because he doesn't _define_ rotation
that way; in order for the Moon to rotate as he
defines it, he would have to see the *Earth* rise
and set.

That's why I had to get into the much more complicated
argument that refers to libration - to show why his
definition of rotation, while superficially attractive,
is not the only reasonable one, and astronomers have
a very good reason to use, in the case of the Moon
at least, the different definition that they do in
fact use.

John Savard

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From Newsgroup: sci.astro.amateur

On Sat, 24 Feb 2024 03:04:55 -0000 (UTC), Quadibloc <quadibloc@servername.invalid> wrote:

On Fri, 23 Feb 2024 23:35:24 +0000, palsing wrote:

Also, if you were to be living on the far side of
the moon you would never see the Earth, but you
*would* see the Sun rise and set about every 29.53
days, which is a pretty good indication that it is
indeed rotating on its axis.

That's true, but he already _knows_ that this does
happen. He doesn't view that as "proving" that the
Moon rotates, because he doesn't _define_ rotation
that way; in order for the Moon to rotate as he
defines it, he would have to see the *Earth* rise
and set.

That's why I had to get into the much more complicated
argument that refers to libration - to show why his
definition of rotation, while superficially attractive,
is not the only reasonable one, and astronomers have
a very good reason to use, in the case of the Moon
at least, the different definition that they do in
fact use.

John Savard

I'd stick with simple. If the Moon doesn't rotate, why does a Focault
pendulum work there? Why does an accelerometer sitting at a pole
produce a signal consistent with a one month rotation period?
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From Newsgroup: sci.astro.amateur

On Fri, 23 Feb 2024 21:18:46 -0700, Chris L Peterson wrote:

I'd stick with simple. If the Moon doesn't rotate, why does a Focault pendulum work there? Why does an accelerometer sitting at a pole
produce a signal consistent with a one month rotation period?

The problem is that sticking with simple doesn't really address his
argument. It's not about whether or not the Moon rotates physically
as you understand it; what you and I call rotation, he calls
"stellar circumpolar motion", and claims that it's an error to
equate that with rotation, which is properly measured relative to
the orbital path of a planet or moon.

That's why he gave the example of a car going around in a traffic
circle (called a "roundabout" in Britain, and presumably also in
Eire). We don't consider the car to be spinning as it goes around
in a circle, even though it does change its orientation relative to
the points of the compass. It's natural for a car to always have
its front pointed in the way in which it is going.

So he asks why we shouldn't talk about the Moon the same way.
Only by getting into libration can I establish why astronomers
think of the Moon's rotation separately from its orbit. Of course,
Oriel36 doesn't really seem to be willing to pay attention to my
arguments for long enough for them to have any effect - but if
I'm going to respond to what he says, I feel I need to respond with
the points that are actually relevant to the issue he is in fact
raising.

In order to have a meaningful debate with someone, you have to get
inside the other person's head - to understand basic things like
what he means by the words he uses.

In the case of Oriel36, he is operating from a world view which is
_profoundly_ alien to that of the other posters in this newsgroup.

When he talks about Newton, he often refers to "denominational
Christianity", and complains about his empiricism.

This is a tip-off as to where his problem with Newton lies.

Newton, unlike Copernicus, Galileo, and Kepler, was a Protestant
instead of a Roman Catholic. And Oriel36 feels that the _Principia
Mathematica Philosophiae Naturalis_ of Newton, being empirical in
nature, is written in a barren, incomplete system of reasoning.

As opposed to the right and proper system of reasoning to be used
when debating serious questions. Mediaeval Scholasticism! Who does
this Isaac Newton think he is, to think he knows better than Thomas
Aquinas?

Personally, I have a sneaking suspicion that the reasoning of
Galileo and Kepler, at least, if not Copernicus, was not all that
much different from Newton's, but given that Oriel36 goes around
quoting these people in the original Latin, I'm not really
prepared to debate that issue with him. I'd be afraid he might
cut me to ribbons unless I was as knowledgeable about the greats
of early astronomy as Owen Gingerich.

My natural reaction to someone with Oriel36's world view who
proposes to be taken seriously these days on matters of physical
science... is to look at him funny.

But I can't really give in to that tendency if I expect to have a
productive discussion.

Mediaeval Scholasticism may well be a useful system of reasoning for
talking about the Big Questions in *philosophy*. In the natural
sciences, however, not only is mere empiricism sufficient, but it
is more reliable, allowing us to remain on solid ground to reach
sure conclusions.

I mean, it's not exactly an accident that, following Newton, we
wound up in a world of steam engines, rocket ships, telegraphy,
radio, and television, lasers, computers, and so on and so forth.
Getting so far, so fast, in science and engineering requires being
able to build on what has been done before in a reliable manner.

If you include uncertain and speculative elements in your reasoning,
you can't proceed that far without making mistakes that lead to
constant back-tracking.

And that's why his world view is very much a minority position.

Thanks to Newton coming up with universal gravitation as the explanation
for the motions of the Solar System... Copernicanism was no longer simply
a matter of taste or opinion. There was a _mechanism_ by which the Solar
System could work, if the Sun were at the center... with the Earth at
the center, on the other hand, the motions of the planets now made no
sense at all.

So the debate on the world systems was _over_. No room remained for heliocentric astronomy, or even for compromises like that of Tycho
Brahe. That's why the modern world sees Newton as the one who completed
the revolution that Copernicus started.

John Savard
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From Newsgroup: sci.astro.amateur

On Sat, 24 Feb 2024 04:56:58 -0000 (UTC), Quadibloc <quadibloc@servername.invalid> wrote:

On Fri, 23 Feb 2024 21:18:46 -0700, Chris L Peterson wrote:

I'd stick with simple. If the Moon doesn't rotate, why does a Focault
pendulum work there? Why does an accelerometer sitting at a pole
produce a signal consistent with a one month rotation period?

The problem is that sticking with simple doesn't really address his >argument...

No, the problem is that he's living in a bizarre dogmatic bubble such
that NO argument will ever allow him to recognize something so simple
that 2nd graders understand it after a simple classroom activity where
one person plays the Earth and another the Moon.
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From Newsgroup: sci.astro.amateur

Though you were gone with your "farewell" post on the 20th. Looked
forward to the door NOT hitting your backside upon your fast exit, but unfortunately you are still here and posting your irrelevant fecal
matter. What gives?
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From Newsgroup: sci.astro.amateur

On Sun, 25 Feb 2024 05:47:13 -0500, Jake M <mill45@fla.net> wrote:

Though you were gone with your "farewell" post on the 20th. Looked
forward to the door NOT hitting your backside upon your fast exit, but >unfortunately you are still here and posting your irrelevant fecal
matter. What gives?

Clinical, pathological obsession.
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From Newsgroup: sci.astro.amateur

On Sun, 25 Feb 2024 05:47:13 -0500, Jake M <mill45@fla.net> wrote:

Though you were gone with your "farewell" post on the 20th. Looked
forward to the door NOT hitting your backside upon your fast exit, but >unfortunately you are still here and posting your irrelevant fecal
matter. What gives?

Although Google Groups no longer provides USENET access, an
online web-based interface to numerous USENET groups, including
this one, is available at

https://www.novabbs.com/

making it possible for people to post here without the complexities of
setting up a newsreader to talk to Eternal September.

That made it possible for him to continue participating in the
discussion here.

John Savard
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From Newsgroup: sci.astro.amateur

On Sat, 24 Feb 2024 08:06:40 -0700, Chris L Peterson
<clp@alumni.caltech.edu> wrote:

No, the problem is that he's living in a bizarre dogmatic bubble such
that NO argument will ever allow him to recognize something so simple
that 2nd graders understand it after a simple classroom activity where
one person plays the Earth and another the Moon.

Well, it _is_ also true that he refuses to pay attention to my replies
to him, and open his mind to the possibility that, given that the
whole world seems to disagree with him, that just maybe he might
be wrong.

So you are indeed right that I am unlikely to change his mind.

I hope, though, that having the correct arguments on record will
at least help prevent him from misleading others.

But "something so simple that 2nd graders understand it"? Well, when
he compared the Moon to a car going around in a traffic circle, it's
clear that he _does_ understand what that demonstration shows.

A car going around in a traffic circle changes its orientation
relative to the points of the compass. Just as the Moon changes
its orientation relative to the fixed stars. He _knows_ this
already.

But his point is that people don't say the car is spinning, as
it would be if it lost traction when driving on ice. The car is
oriented the way it should be, so the driver can see where
he is going.

So the car's orientation follows its motion. Which makes sense
for a car - the driver needs to see where he's going!

As for the Moon? When we say that the Moon rotates, even
though its rotation matches its orbit in period... we're following
a conceptualization of motion that comes from Isaac Newton.

Because the Moon is in airless space, and so not subject to
friction, it obeys the laws of motion in a simple manner. Laws
like conservation of angular momentum. But all of this stuff
fails to impress him; he thinks Calculus is some kind of mumbo
jumbo that is being practiced becaus of... hero worship, or
something.

John Savard
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