[Ansteorra] Fee Increase and other Business...

[Rose]

I love this list...

-R

Wonder is the cause of delight because it carries the hope of discovery.     -Thomas Aquinas

--- On Fri, 2/19/10, Tim McDaniel <tmcd at panix.com> wrote:

From: Tim McDaniel <tmcd at panix.com>
Subject: Re: [Ansteorra] Fee Increase and other Business...
To: "Kingdom of Ansteorra - SCA, Inc." <ansteorra at lists.ansteorra.org>
Date: Friday, February 19, 2010, 2:04 PM

On Fri, 19 Feb 2010, Donnchadh Beag mac Griogair
<donnchadh at cornelius.norman.ok.us> wrote:
> I just had a thought as to why people may differ in considering it
> charging extra vs a discount.  It's all a matter of reference.  If
> you ask a physicist how fast a celestial body is moving through
> space, the first question they're going to ask, is "in reference to
> what?"  Without a point of reference, you can't tell what change is
> happening.

The rest of this posting is Physics 101 geekery, so if you're
allergic, delete this message at once.

That's actually an excellent analogy to the NMS.  Unfortunately,
I think it torpedoes your point.

Not all frames of reference are identical or equally useful.  "In flat
spacetimes, all inertial frames of reference are in a state of
constant, uniform motion with respect to one another."  That is, in
the absence of gravity &c and at slow relative speeds, if we're
approaching each other at a constant relative speed of 10 m/s, we
change choose a point to measure our movements in any way we find
convenient.  Newton's laws work regardless of the point of reference
chosen.

But suppose I turn on a rocket, or suppose I'm tied to the outside of
a rotating drum.  My point of view is a non-inertial frame of
reference.  I feel acceleration.  I don't have to refer to any
external reference point to know that there's acceleration.  Being a
non-inertial frame of reference, Newton's laws (and Einstein's special
relativity) stop working in their simplest forms.  An object at rest
doesn't remain at rest unless acted upon: it accelerates.  In a frame
that's rotating at angular rate omega,
    F = ma
is incorrect: it's
    F = ma - 2m(omega) cross (v sub B)
           - m(omega) cross (omega cross (x sub B)
           - m(d omega/dt) cross (x sub B)
at least if <http://en.wikipedia.org/wiki/Inertial_frame_of_reference>
be trusted.  The extra terms are called "fictitious forces".

You can still do physics, but the equations get hairy and it's a
problem translating a non-inertial frame into another frame.
For a rotating disk, you get Coriolanus force, centrifugal force, and
the Euler force.  And there's no apparent physical cause, unlike (say)
someone shoving a table -- the forces spring out of nowhere.

So, to go back to the NMS: considering it as a member discount makes
the equations go hairy, in ways that Robin and I have said.  There are
forbidden fee levels.  You don't give member discounts to certain
youth, but you don't kick back any money to the corporation either,
unlike adults.  Et cetera.  Those are the "fictitious forces" that
complicate everything.

But the complications vanish away when you simply consider it as a
non-member surcharge -- it's then relatively easy to explain.

Danet Lincoln
-- Tim McDaniel, tmcd at panix.com
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