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
--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)