On 03/24/2024 07:09 AM, J. J. Lodder wrote:
LaurenceClarkCrossen <clzb93ynxj@att.net> wrote:
>
You're mistaken about infinity not being in Euclid's parallel lines
according to his article:
>
"He began by studying Euclid's postulate that a straight line has infinite
length."
>
>
"THE PARALLEL POSTULATE"
>
Author(s): Raymond H. Rolwing and Maita Levine
>
Source: The Mathematics Teacher, Vol. 62, No. 8 (DECEMBER 1969), pp. 665-669
>
Published by: National Council of Teachers of Mathematics
>
Stable URL: http://www.jstor.org/stable/27958258
>
I think that the geometries opposed to Euclid do not contradict his
because they depart from plane geometry. For example, a triangle with
other than 180 degrees is not on a plane surface, nor are parallel lines
that diverge or meet. please read the article and see what I mean!
>
Euclid's geometry is about plane geometry and the non-Euclidean's are not.
>
Euclid's 5th postulate can (and was) given as:
===
5. If two lines are drawn which intersect a third in such a way that the
sum of the inner angles on one side is less than two right angles, then
the two lines inevitably must intersect each other on that side if
extended far enough. This postulate is equivalent to what is known as
the parallel postulate. (Wolfram)
===
>
The domain of Euclidean geometry is the open Euclidean plane.
No actual infinity is involved, [1]
>
Jan
>
[1] You can extent Euclidean geometry by adding a 'point at infinity'.
This is called projective geometry, and it is something else.
(and also irrelevant for disproving general relativity)
>
>
I think that "Relativity" with an interpretation that
"L-principle of SR is light's speed is an E-spacial constant",
that the Light-principle is an Einstein-spacial, everywhere
local, constant, and that "Equivalence principle is up
to terms, mass-energy equivalency in the E-spatial
rotationally while Galilean linearly", then, first of all
that otherwise there are various notions of what the
principles of Relativity are, that the notions above are
Einstein's theory of Relativity that he arrived at if not
so much his first take or the usual mantras, the second,
that infinity does get involved, because of all the
higher-order moments, and it being about singular points,
about 0, 1, and infinity.
Why Einstein introduces two terms, "spacial" for SR and
"spatial" for GR, is a thing, that most don't know there's
a difference, and when things besides light are at rest,
there isn't, yet, that's usually only an abstract situation.
It's like if Einstein's idea about the clock face is that,
"if all of a sudden, time stopped moving and I moved away,
the clock face would also stop", and it's like, "well yeah,
Einstein, that would mean time stopped".
And it's like, "if I, Einstein, saw a women drop her glasses
on the train, it would be an arc", it's like, "Einstein, you
would see her as an arc, too".
So, I think most people's thought experiments in relativistic
dynamics, usually leave out properties of continuity, which
has also that usual formalisms of geometry, often leave out
a postulate of continuity, yet, it was kind of noticed to be
necessary and since Hilbert it's sort of included.
Is it Mach-ian? Einstein's later, greater theory, Relativity,
has the L-principle and an EQ-principle, and separate E-spacial
and E-spatial, and doesn't need much fixing, only rather the
mathematics that Mathematics _owes_ Physics, of higher-order
moments, to arrive at a fuller continuum mechanics, and very
much so to arrive at though that light's speed c can be in
natural units, "1", that c_g, gravity's, remains, "infinity".
So, I think most people's developments with or against Relativity,
have it that it's not what Einstein arrived at and maintains
as his last word, as out of "Out of My Later Years".
So, geometry has also a "postulate of continuity".