Log24 Posts for Tuesday, July 6, 2010

Tuesday, July 6, 2010

Window, continued

 m759 @ 10:31 AM 

"Simplicity, simplicity, simplicity!  I say, let your affairs
be as two or three, 
and not a hundred or a thousand;
instead of a million count half a dozen,
and keep your accounts on your thumb-nail."
– Henry David Thoreau, Walden

This quotation is the epigraph to Section 1.1 of
Alexandre V. Borovik's 
Mathematics Under the Microscope:

Notes on Cognitive Aspects of Mathematical Practice

(American Mathematical Society, Jan. 15, 2010, 317 pages).

From Peter J. Cameron's review notes for
his new course in group theory

http://www.log24.com/log/pix10A/100705-CameronExample.jpg

From Log24 on June 24

Geometry Simplified

Image-- The Four-Point Plane: A Finite Affine Space
(an affine  space with subsquares as points
and sets  of subsquares as hyperplanes)

Image-- The Three-Point Line: A Finite Projective Space
(a projective  space with, as points, sets
  of line segments that separate subsquares)

Exercise

Show that the above geometry is a model
for the algebra discussed by Cameron.


Tuesday, July 6, 2010

Thoreau on Group Theory

 m759 @ 1:00 PM 

"Instead of a million count half a dozen." —Walden

"Of all the symmetric groups, S6 is perhaps the most remarkable."
 Notes 2 (Autumn 2008), apparently by Robert A. Wilson,
   for Group Theory, MTH714U

For a connection of MTH714U with Walden, see "Window, continued."

For a connection of "Window" with the remarkable S6, see Inscapes.

For some deeper background, see Wilson's "Exceptional Simplicity."


Tuesday, July 6, 2010

What “As” Is

 m759 @ 8:00 PM

or:  Combinatorics (Rota) as Philosophy (Heidegger) as Geometry (Me)

"Dasein’s full existential structure is constituted by
the 'as-structure' or 'well-joined structure' of the rift-design*…"

– Gary Williams, post of January 22, 2010

Background—

Gian-Carlo Rota on Heidegger…

"… The universal as  is given various names in Heidegger's writings….

The discovery of the universal as  is Heidegger's contribution to philosophy….

The universal 'as' is the surgence of sense in Man, the shepherd of Being.

The disclosure of the primordial as  is the end of a search that began with Plato….
This search comes to its conclusion with Heidegger."

– "Three Senses of 'A is B' in Heideggger," Ch. 17 in Indiscrete Thoughts

… and points as separating rifts

Image-- The Three-Point Line: A<br />
Finite Projective Space

    Click image for details.

* rift-design— Definition by Deborah Levitt

"Rift.  The stroke or rending by which a world worlds, opening both the 'old' world and the self-concealing earth to the possibility of a new world. As well as being this stroke, the rift is the site— the furrow or crack— created by the stroke. As the 'rift design' it is the particular characteristics or traits of this furrow."

– "Heidegger and the Theater of Truth," in Tympanum: A Journal of Comparative Literary Studies, Vol. 1, 1998


Tuesday, July 6, 2010

A Serious Artist

 m759 @ 10:00 PM 

Today's Google logo 
honors a serious artist:

Image-- Frida Kahlo in Google logo July 6, 2010

Related material:

Holy Saturday, 2004

That post quotes the words of another serious artist,
Malcolm Lowry, on a barranca, or deep ravine.
(See also Heidegger's "rift" concept.)

For a less serious rift, see the art of Kylie Minogue.


Tuesday, July 6, 2010

Bright Star

 m759 @ 10:30 PM

"Ya la ronda llega aquí."

A room by the architect Luis Barragán.