On 12/2/2025 1:24 AM, Alan Grayson wrote:


On Monday, December 1, 2025 at 10:37:16 PM UTC-7 Russell Standish wrote:

    On Mon, Dec 01, 2025 at 08:07:14PM -0800, Alan Grayson wrote:
    >
    >
    > On Monday, December 1, 2025 at 3:46:40 PM UTC-7 Russell Standish
    wrote:
    >
    > On Sat, Nov 29, 2025 at 11:13:05PM -0800, Alan Grayson wrote:
    > >
    > >
    > > On Friday, November 28, 2025 at 3:26:03 PM UTC-7 Russell
    Standish wrote:
    > >
    > > Sorry - I can't make sense of your question.
    > >
    > >
    > > The Axiom of Choice (AoC) asserts that given an uncountable
    set of sets,
    > each
    > > one being
    > > uncountable, there is a set composed of one element of each
    set of the
    > > uncountable set
    > > of sets. The AoC doesn't tell us how such a set is
    constructed, only that
    > we
    > > can assume it
    > > exists. So, in chosing an origin for the coordinate system for
    a plane
    > say, we
    > > have to apply
    > > the AoC for a single uncountable set, the plane. But there's
    no way to
    > > construct it. Does
    > > this make sense? AG
    > >
    >
    > I don't see the axiom of choice has much bearing here. To choose an
    > origin, we simply need to choose one point from a single
    uncountable
    > set of points. We label finite sets of points all the time -
    geometry
    > would be impossible otherwise - consider triangles with vertices
    > labelled A,B and C.
    >
    >
    > You write "we simply need to choose one point from a single
    uncountable set
    > points", but how exactly can we do that! That's the issue, the
    construction of
    > the coordinate system. In fact, there's no credible procedure
    for doing that,
    > so
    > we need the AoC to assert that it can be done. IMO, this is an
    esoteric issue.
    > For example, we can't just assert we can use the number ZERO to
    construct
    > the real line, since with ZERO we have, in effect, a coordinate
    system.AG
    >

    Rubbish - it is not controversial to pick a set of points from a
    finite set of uncountable sets. As I said, we've been doing that
    since
    building ziggurats on the Mesopotamian plain. AoC is only
    controversial when it comes to uncountable sets of uncountable sets.


*It's subtle, maybe too subtle for you to see its relevance. You're imaginIng throwing* *a dart at a flat piece of paper, but that falls far short of a viable/construction /of a * *coordinate system on a plane. You can imagine it being done and that's the extent*
*of your proof. AG *
A coordinate system is anything that supplies a unique set of numbers to label every point such that the numbers are continuous. I think you have and exaggerated idea of what needs to be constructed.

Brent

--
You received this message because you are subscribed to the Google Groups 
"Everything List" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To view this discussion visit 
https://groups.google.com/d/msgid/everything-list/8e64816b-9545-47fc-9a34-3dd842963e8a%40gmail.com.

Reply via email to