Log24

Thursday, July 2, 2026

Coordinatization

Filed under: General — Tags: , — m759 @ 3:26 pm

Putting Descartes Before Dehors

      

"Descartes déclare que c'est en moi, non hors de moi,
en moi, non dans le monde, que je pourrais voir
si quelque chose existe hors de moi."

ATRIUM, Philosophie

Wednesday, February 25, 2026

Diagrams

Filed under: General — Tags: , , — m759 @ 8:25 am

Not So Blank —

McLuhan's "Retrieves" part —

From Hudson's 1905 classic
Kummer's Quartic Surface

For those who prefer bullshit, a first-rate example of the genre —

Wednesday, January 14, 2026

Ex Fano Apollinis
Grok Benchmark

Filed under: General — Tags: , , — m759 @ 12:23 am

Grok showed admirable persistence and depth in its research, but failed
to completely understand what is meant by "coordinatization of a 3×3 array."
It did, however, indicate a related concept in a suggested further prompt.

For the example that suggested the original prompt, see The Coxeter Aleph.

Monday, May 13, 2024

February 20: A Space Odyssey

Filed under: General — Tags: , , , , , — m759 @ 8:46 am

For the significance of the date "February 20," see . . .

Google One: Gemini Advanced AI on 13 May 2024.

Prompt:

How can Weyl's 1946 remarks on coordinatization in "The Classical Groups" be applied to models of finite geometries?

Response (after several drafts):

In "The Classical Groups," Hermann Weyl discusses the concept of coordinatization, which is the process of assigning numerical coordinates to points in a geometric space. This process is fundamental in connecting abstract geometric concepts with concrete numerical representations, allowing for algebraic manipulation and analysis.

Weyl's remarks on coordinatization have significant implications for models of finite geometries. Finite geometries are geometric systems with a finite number of points and lines, and they often exhibit different properties compared to traditional Euclidean geometry.

Here's how Weyl's ideas can be applied to finite geometries:

1. **Relativity of Coordinatization:** Weyl emphasizes that the choice of coordinate system is arbitrary and that different coordinate systems can be used to describe the same geometric object. This relativity of coordinatization is particularly relevant in finite geometries, where multiple coordinate systems may exist, each with its own advantages and disadvantages.

2. **Equivalent Coordinatizations:** Weyl introduces the concept of "equivalent coordinatizations," which are different coordinate systems that can be transformed into one another through a group of transformations. In finite geometries, identifying and understanding these equivalent coordinatizations can provide deeper insights into the underlying structure and symmetries of the geometry.

3. **Objective Class of Coordinatizations:** Weyl discusses the problem of fixing an "objective class" of coordinatizations that capture essential features of the geometry while being independent of arbitrary choices. In finite geometries, this could involve identifying coordinatizations that best reflect the specific properties and relationships within the geometry.

4. **Group of Transformations:** Weyl emphasizes the role of the "group of transformations" that mediates between equivalent coordinatizations. In finite geometries, understanding these transformation groups can help classify different types of finite geometries and reveal their underlying symmetries.

By applying Weyl's insights, researchers can gain a deeper understanding of finite geometries, including their classification, properties, and relationships. Additionally, exploring different coordinatization schemes can lead to new algebraic and geometric tools for studying finite geometries.

For further exploration, you can delve into the works of other mathematicians like Steven H. Cullinane, who has written extensively on finite geometry and its connections to relativity and other areas of mathematics.

I hope this explanation is helpful! Please let me know if you have any further questions.

Update at about 5 PM ET the same day . . .

Prompt:

Correction: Cullinane has NOT written on finite geometry's "connections to relativity." He has, instead, quoted Weyl's remarks on what Weyl himself called "the relativity problem," but what was in fact his own term for problems involving coordinatization. Such problems are of interest both in physics and in finite geometry, but the latter is a field of pure mathematics, NOT of physics.

Response:

You are absolutely correct. I apologize for the error in my previous response.

Steven H. Cullinane has indeed quoted Weyl's remarks on "the relativity problem" in the context of finite geometry. However, as you rightly pointed out, this term refers to Weyl's own terminology for problems involving coordinatization and not the theory of relativity in physics.

Finite geometry is a field of pure mathematics and does not directly connect to the physical theories of relativity. While both areas involve concepts of space and transformations, they operate in fundamentally different domains.

Cullinane's work focuses on applying Weyl's insights on coordinatization to the specific challenges and structures within finite geometries. This involves exploring different coordinatization schemes, understanding their equivalences, and identifying transformation groups that reveal the underlying symmetries of finite geometries.

Thank you for pointing out this important distinction. It highlights the importance of precise language and accurate attribution when discussing complex mathematical concepts.

Tuesday, March 14, 2023

For Pi Day

Filed under: General — Tags: — m759 @ 8:02 am

Also on January 16, 2014 —

Disney Endings

Filed under: General — Tags: — m759 @ 7:01 am

The New York Times  reports a Monday,
March 13, 2023, death:

This  journal Monday —

Final image of the above "diamond theorem" penrose  search on Monday —

From March 2 —

Monday, February 21, 2022

Variation on an Old Joke

Filed under: General — Tags: — m759 @ 11:02 am

An image linked to* in Mapping Problem Continued (Log24, 16 July 2012) —

* The link is on the phrase "may be deduced."

Sunday, July 19, 2020

Ornaments for Valéry*

Filed under: General — Tags: , — m759 @ 12:27 am

* See Valéry Ornament in this journal.

Sunday, January 19, 2014

Deep Beauty

Filed under: General — Tags: , — m759 @ 11:00 am

(Continued)

Old punchline:  “Spell chrysanthemum.”
Variation:  “Spell coordinatization.”

Related test:  Chrysanthemum Coordinatization —

The image �http://www.log24.com/log/pix06A/060604-Primitive.gif� cannot be displayed, because it contains errors.

Context Root circle.

Saturday, January 18, 2014

The Triangle Relativity Problem

Filed under: General,Geometry — Tags: , , , — m759 @ 5:01 pm

A sequel to last night's post The 4×4 Relativity Problem —

IMAGE- Triangle Coordinatization

In other words, how should the triangle corresponding to
the above square be coordinatized ?

See also a post of July 8, 2012 — "Not Quite Obvious."

Context — "Triangles Are Square," a webpage stemming
from an American Mathematical Monthly  item published
in 1984.

Friday, January 17, 2014

The 4×4 Relativity Problem

The sixteen-dot square array in yesterday’s noon post suggests
the following remarks.

“This is the relativity problem:  to fix objectively a class of
equivalent coordinatizations and to ascertain the group of
transformations S mediating between them.”

— Hermann Weyl, The Classical Groups ,
Princeton University Press, 1946, p. 16

The Galois tesseract  appeared in an early form in the journal
Computer Graphics and Art , Vol. 2, No. 1, February 1977—

IMAGE- Hypercube and 4x4 matrix from the 1976 'Diamond Theory' preprint, as excerpted in 'Computer Graphics and Art'

The 1977 matrix Q is echoed in the following from 2002—

IMAGE- Dolgachev and Keum, coordinatization of the 4x4 array in 'Birational Automorphisms of Quartic Hessian Surfaces,' AMS Transactions, 2002

A different representation of Cullinane’s 1977 square model of the
16-point affine geometry over the two-element Galois field GF(2)
is supplied by Conway and Sloane in Sphere Packings, Lattices and Groups   
(first published in 1988) :

IMAGE- The Galois tesseract as a four-dimensional vector space, from a diagram by Conway and Sloane in 'Sphere Packings, Lattices, and Groups'

Here a, b, c, d   are basis vectors in the vector 4-space over GF(2).
(For a 1979 version of this vector space, see AMS Abstract 79T-A37.)

See also a 2011 publication of the Mathematical Association of America —

From 'Beautiful Mathematics,' by Martin Erickson, an excerpt on the Cullinane diamond theorem (with source not mentioned)

Thursday, January 16, 2014

Confession of a Sucker

Filed under: General,Geometry — Tags: — m759 @ 12:00 pm

Today’s 11 AM (ET) post was suggested by a New York Times
article, online yesterday, about art gallery owner Lisa Cooley.

A check of Cooley’s website yields the image below,
related to Beckett’s Molloy .

For the relevant passage from Molloy , click the following:

I took advantage of being at the seaside
to lay in a store of sucking-stones.

For posts on Molloy  in this journal, click Beckett + Molloy .

Cynthia Daignault, 2011:
The one I shall now describe, if I can…
Oil on linen, in 2 parts: 40 x 30 inches, 96 x 75 inches

Related art theory —

Geometry of the 4×4 Square 

Tuesday, April 10, 2012

Dehors*

Filed under: General — Tags: , , — m759 @ 10:31 am

"A New York Jew imitates D. H. Lawrence at his peril."

The New York Times  today

“Our focus is on creating very high quality, highly artistically produced programs that bring together worlds that usually don’t talk to each other,” said Dr. Greene, a physics and math professor at Columbia and well-known popularizer of science. “We’ve tried to inject the drama of science into these highly produced programs, so people leave the event saying, ‘Wow, I didn’t know that’s what science is like.’ ”

As for D. H. Lawrence, see this journal on September 10, 2003.

* For the title, see last night's Turing Gate.

Tuesday, February 16, 2010

Mysteries of Faith

Filed under: General,Geometry — Tags: , , , — m759 @ 9:00 am

From today's NY Times

http://www.log24.com/log/pix10/100216-NYTobits.jpg

Obituaries for mystery authors
Ralph McInerny and Dick Francis

From the date (Jan. 29) of McInerny's death–

"…although a work of art 'is formed around something missing,' this 'void is its vanishing point, not its essence.'"

Harvard University Press on Persons and Things (Walpurgisnacht, 2008), by Barbara Johnson

From the date (Feb. 14) of Francis's death–

2x2x2 cube

The EIghtfold Cube

The "something missing" in the above figure is an eighth cube, hidden behind the others pictured.

This eighth cube is not, as Johnson would have it, a void and "vanishing point," but is instead the "still point" of T.S. Eliot. (See the epigraph to the chapter on automorphism groups in Parallelisms of Complete Designs, by Peter J. Cameron. See also related material in this journal.) The automorphism group here is of course the order-168 simple group of Felix Christian Klein.

For a connection to horses, see
a March 31, 2004, post
commemorating the birth of Descartes
  and the death of Coxeter–

Putting Descartes Before Dehors

     Binary coordinates for a 4x2 array  Chess knight formed by a Singer 7-cycle

For a more Protestant meditation,
see The Cross of Descartes

Descartes

Descartes's Cross

"I've been the front end of a horse
and the rear end. The front end is better."
— Old vaudeville joke

For further details, click on
the image below–

Quine and Derrida at Notre Dame Philosophical Reviews

Notre Dame Philosophical Reviews

Wednesday, March 31, 2004

Wednesday March 31, 2004

Filed under: General — Tags: , , , , — m759 @ 12:25 am

To Be

A Jesuit cites Quine:

"To be is to be the value of a variable."

— Willard Van Orman Quine, cited by Joseph T. Clark, S. J., in Conventional Logic and Modern Logic: A Prelude to Transition,  Woodstock, MD: Woodstock College Press, 1952, to which Quine contributed a preface.

Quine died in 2000 on Xmas Day.

From a July 26, 2003, entry,
The Transcendent Signified,
on an essay by mathematician
Michael Harris:

Kubrick's
monolith

Harris's
slab

From a December 10, 2003, entry:

Putting Descartes Before Dehors

      

"Descartes déclare que c'est en moi, non hors de moi, en moi, non dans le monde, que je pourrais voir si quelque chose existe hors de moi."

ATRIUM, Philosophie

For further details, see ART WARS.

The above material may be regarded as commemorating the March 31 birth of René Descartes and death of H. S. M. Coxeter.

For further details, see

Plato, Pegasus, and the Evening Star.

Wednesday, December 10, 2003

Wednesday December 10, 2003

Filed under: General — Tags: , — m759 @ 6:13 pm

Putting Descartes Before Dehors

      

"Descartes déclare que c'est en moi, non hors de moi, en moi, non dans le monde, que je pourrais voir si quelque chose existe hors de moi."

ATRIUM, Philosophie

For further details, see ART WARS.

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