Log24

Friday, January 17, 2020

September Morn

Filed under: General — Tags: — m759 @ 10:17 PM

Epigraph from Ch. 4 of Design Theory , Vol. I:

"Es is eine alte Geschichte,
 doch bleibt sie immer neu 
"
 —Heine (Lyrisches Intermezzo  XXXIX)

This epigraph was quoted here earlier on
the morning of September 1, 2011.

Design Theory

Filed under: General — Tags: , — m759 @ 12:57 PM

On a recently deceased professor emeritus of architecture
at Princeton —

"… Maxwell  'established the school as a principal
center of design research, history and theory.' ”

"This is not the Maxwell you're looking for."

Thursday, September 1, 2011

How It Works

Filed under: General,Geometry — Tags: , , , — m759 @ 11:00 AM

“Design is how it works.” — Steven Jobs (See Symmetry and Design.)

“By far the most important structure in design theory is the Steiner system S(5, 8, 24).”
— “Block Designs,” by Andries E. Brouwer

IMAGE- Harvard senior thesis on Mathieu groups, 2010, and supporting material from book 'Design Theory'

The name Carmichael is not to be found in Booher’s thesis.  A book he does  cite for the history of S(5,8,24) gives the date of Carmichael’s construction of this design as 1937.  It should  be dated 1931, as the following quotation shows—

From Log24 on Feb. 20, 2010

“The linear fractional group modulo 23 of order 24•23•11 is often represented as a doubly transitive group of degree 24 on the symbols ∞, 0, 1, 2,…, 22. This transitive group contains a subgroup of order 8 each element of which transforms into itself the set ∞, 0, 1, 3, 12, 15, 21, 22 of eight elements, while the whole group transforms this set into 3•23•11 sets of eight each. This configuration of octuples has the remarkable property that any given set of five of the 24 symbols occurs in one and just one of these octuples. The largest permutation group Γ on the 24 symbols, each element of which leaves this configuration invariant, is a five-fold transitive group of degree 24 and order 24•23•22•21•20•48. This is the Mathieu group of degree 24.”

– R. D. Carmichael, “Tactical Configurations of Rank Two,” in American Journal of Mathematics, Vol. 53, No. 1 (Jan., 1931), pp. 217-240

Epigraph from Ch. 4 of Design Theory , Vol. I:

Es is eine alte Geschichte,
doch bleibt sie immer neu

—Heine (Lyrisches Intermezzo  XXXIX)

See also “Do you like apples?

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