Log24

Sunday, July 7, 2019

Schoolgirl Problem

Filed under: General — Tags: , — m759 @ 11:18 PM

Anonymous remarks on the schoolgirl problem at Wikipedia —

"This solution has a geometric interpretation in connection with 
Galois geometry and PG(3,2). Take a tetrahedron and label its
vertices as 0001, 0010, 0100 and 1000. Label its six edge centers
as the XOR of the vertices of that edge. Label the four face centers
as the XOR of the three vertices of that face, and the body center
gets the label 1111. Then the 35 triads of the XOR solution correspond
exactly to the 35 lines of PG(3,2). Each day corresponds to a spread
and each week to a packing
."

See also Polster + Tetrahedron in this  journal.

There is a different "geometric interpretation in connection with
Galois geometry and PG(3,2)" that uses a square  model rather
than a tetrahedral  model. The square  model of PG(3,2) last
appeared in the schoolgirl-problem article on Feb. 11, 2017, just
before a revision that removed it.

Saturday, August 25, 2018

Schoolgirl Problem

Filed under: General — Tags: — m759 @ 5:40 PM

For Pagan Moore

http://www.log24.com/log/pix18/180825-Wicker_Man-scene.jpg

See also "as frivolous as a willow on a tombstone."

Sunday, July 15, 2018

Schoolgirl Problems

Filed under: General — m759 @ 12:00 PM

A Warren, Pennsylvania, newspaper article from May 12, 2018,
"A terrorist among them," quotes Ann Creal of Warren on
schooldays of the late 1950's and on a German exchange student,
Gudrun Ensslin, who later became famous for her violent political
activities:

"She said Ensslin dated while here (the man
she identified as Ensslin’s date told the Times Observer
he had no recollection of her)."

I am the man that was identified as Ensslin's date, and I still
have no recollection of her.

Ann Creal is the former Ann Fuellhart, who was a college freshman
in the fall of 1959, when I was a high school senior —

Ann Creal apparently confused me with Scott Mohr, who
graduated from Warren High School in 1958. See the Log24
posts Crux and Doppelgänger.
 

Tuesday, November 29, 2016

Schoolgirl Problem

Filed under: General — m759 @ 2:14 AM

Thursday, August 4, 2016

Schoolgirl Problems

Filed under: General — m759 @ 12:00 PM

Compare and contrast the recent films
"The Diary of a Teenage Girl" and "Strangerland." 

(This post was suggested by yesterday's
"How Deep the Rabbit Hole Goes.")

Monday, February 22, 2016

Schoolgirl Problems

Filed under: General — m759 @ 10:10 AM

and versions of "Both Sides Now"

See a New York Times  version of "Both Sides Now."

I prefer a version by Umberto Eco.

Related material for storytellers and the Church of Synchronology

This journal on the date of the above shooting script, 03/19/15.

Tuesday, September 15, 2015

Schoolgirl Problem

Filed under: General,Geometry — m759 @ 2:00 PM

Or: Ten Years and a Day

In memory of film director Robert Wise,
who died ten years ago yesterday.

A search in this journal for "Schoolgirl" ends with a post
from Sept. 10, 2002, The Sound of Hanging Rock.

See as well a Log24 search for "Strangerland"
(a 2015 film about a search for a schoolgirl) and
a Log24 search for "Weaving."

Related mathematics:  Symplectic.

Some related images (click to enlarge) —

Friday, August 14, 2015

Schoolgirl Problem

Filed under: General,Geometry — m759 @ 6:00 PM

But first, a word from our sponsa* 

Sir Laurence Olivier in "Term of Trial" (1962),
a film starring Sarah Miles as a schoolgirl —

* Bride  in Latin. See also "bride's chair,"
  a phrase from mathematical pedagogy.

Friday, June 19, 2015

Schoolgirl Problem

Filed under: General — m759 @ 12:30 PM

The star of the new film "Chappie" is on tour.

Friday, September 27, 2019

Algebra for Schoolgirls

Filed under: General — Tags: , — m759 @ 8:37 AM

The 15 points of the finite projective 3-space PG(3,2)
arranged in tetrahedral form:

The letter labels, but not the tetrahedral form,
are from The Axioms of Projective Geometry , by
Alfred North Whitehead (Cambridge U. Press, 1906).

The above space PG(3,2), because of its close association with
Kirkman's schoolgirl problem, might be called "schoolgirl space."

Screen Rant  on July 31, 2019:

A Google Search sidebar this morning:

Apocalypse Soon!

Wednesday, September 18, 2019

Powers of X

Filed under: General — m759 @ 11:45 AM

Screen Rant  on July 31, 2019 —

The above space PG(3,2), because of its close association with
Kirkman's schoolgirl problem, might be called "schoolgirl space."

See as well a Log24 post from the above Screen Rant  date —

The Epstein Chronicles, or:  Z  is for Zorro .

Saturday, August 10, 2019

Schoolgirl Space* Revisited:

Filed under: General — Tags: , — m759 @ 10:51 PM

The Square "Inscape" Model of
the Generalized Quadrangle W(2)

Click image to enlarge.

* The title refers to the role of PG (3,2) in Kirkman's schoolgirl problem.
For some backstory, see my post Anticommuting Dirac Matrices as Skew Lines
and, more generally, posts tagged Dirac and Geometry.

Tuesday, April 30, 2019

Heraldry for Walpurgisnacht

Filed under: General — m759 @ 11:05 AM

A problem not only at Harvard.

For instance… A Hollywood anticlerical classic:

Schoolgirl Problem

Tuesday, January 2, 2018

Debs and Redhead

Filed under: General — Tags: — m759 @ 3:15 PM

Or:  Schoolgirl Problems

The above images were suggested in part by the birthdays
on Sept. 21, 2011, of Bill Murray and Stephen King.

More seriously, also in this journal on that date, from a post
titled Symmetric Generation —

Sunday, November 12, 2017

Review

Filed under: General,Geometry — m759 @ 7:04 PM
 

Sunday, October 29, 2017

File System… Unlocked

Filed under: Uncategorized — m759 @ 2:16 PM 

. . . .

"Wikipedia's first true logo . . . . included a quote from the preface
of Euclid and His Modern Rivals  by Lewis Carroll . . . ." 

. . . .

Related dialogue from the new film "Unlocked" —

1057
01:31:59,926 –> 01:32:01,301
Nice to have you back, Alice.

1058
01:32:04,009 –> 01:32:05,467
Don't be a stranger.

See as well Chloë Grace Moretz portraying  a schoolgirl problem.

Thursday, November 2, 2017

History of Mathematics for All Souls’ Day

Filed under: General — m759 @ 9:00 AM

Schoolgirl Problem  

"Buy this image" . . . Or not.

Related material from the date of the above photo —

For related drama, see "Child's Play" in this journal.

Thursday, October 12, 2017

Gifted Continues

Filed under: General — m759 @ 10:00 AM

Related material — See Gifted in this journal.

See as well Tulips.

Yesterday was the International Day of the Girl Child . . .
A related archived Wikipedia article on Kirkman's schoolgirl problem:

See also the previous post— "IPFS Version"— and https://ipfs.io/.

Wednesday, July 5, 2017

Imaginarium of a Different Kind

Filed under: General,Geometry — m759 @ 9:00 PM

The title refers to that of the previous post, "The Imaginarium."

In memory of a translator who reportedly died on May  22, 2017,
a passage quoted here on that date —

Related material — A paragraph added on March 15, 2017,
to the Wikipedia article on Galois geometry

George Conwell gave an early demonstration of Galois geometry in 1910 when he characterized a solution of Kirkman's schoolgirl problem as a partition of sets of skew lines in PG(3,2), the three-dimensional projective geometry over the Galois field GF(2).[3] Similar to methods of line geometry in space over a field of characteristic 0, Conwell used Plücker coordinates in PG(5,2) and identified the points representing lines in PG(3,2) as those on the Klein quadric.

— User Rgdboer

Thursday, February 16, 2017

Schoolgirls and Heptads

Filed under: General,Geometry — m759 @ 11:32 AM

A Feb. 12 note in the "talk" section of the Wikipedia article
"Kirkman's schoolgirl problem" —

The illustration above was replaced by a new section in the article,
titled "Galois geometry."

The new section improves the article by giving it greater depth.  
For related material, see Conwell Heptads in this journal
(or, more generally, Conwell) and a 1985 note citing Conwell's work.

Wednesday, June 1, 2016

Mathematics and Narrative

Filed under: General — m759 @ 12:06 PM

Principles before Personalities — AA  Saying .

Principles —

See Schoolgirl Problem in Wikipedia.

Personalities — 

See Alexandra Alter in the May 26 online New York Times :

"With the proliferation of 'girl' titles,
there are signs that the trend may have peaked;
it already seems ripe for parody." 

Update of 12:40 PM ET on Wednesday, June 1, 2016 —

A note for the Church of Synchronology 
See a post from this  journal on the date of the Alter piece, May 26:

(Click image for the rest of the post .)

Monday, May 30, 2016

Perfect Universe

Filed under: General,Geometry — Tags: — m759 @ 7:00 PM

(A sequel to the previous post, Perfect Number)

Since antiquity,  six has been known as
"the smallest perfect number." The word "perfect"
here means that a number is the sum of its 
proper divisors — in the case of six: 1, 2, and 3.

The properties of a six-element set (a "6-set") 
divided into three 2-sets and divided into two 3-sets
are those of what Burkard Polster, using the same 
adjective in a different sense, has called 
"the smallest perfect universe" — PG(3,2), the projective
3-dimensional space over the 2-element Galois field.

A Google search for the phrase "smallest perfect universe"
suggests a turnaround in meaning , if not in finance, 
that might please Yahoo CEO Marissa Mayer on her birthday —

The semantic  turnaround here in the meaning  of "perfect"
is accompanied by a model  turnaround in the picture  of PG(3,2) as
Polster's tetrahedral  model is replaced by Cullinane's square  model.

Further background from the previous post —

See also Kirkman's Schoolgirl Problem.

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