Log24

Wednesday, January 11, 2012

Cuber

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

"Examples galore of this feeling must have arisen in the minds of the people who extended the Magic Cube concept to other polyhedra, other dimensions, other ways of slicing.  And once you have made or acquired a new 'cube'… you will want to know how to export a known algorithm , broken up into its fundamental operators , from a familiar cube.  What is the essence of each operator?  One senses a deep invariant lying somehow 'down underneath' it all, something that one can’t quite verbalize but that one recognizes so clearly and unmistakably in each new example, even though that example might violate some feature one had thought necessary up to that very moment.  In fact, sometimes that violation is what makes you sure you’re seeing the same thing , because it reveals slippabilities you hadn’t sensed up till that time….

… example: There is clearly only one sensible 4 × 4 × 4 Magic Cube.  It is the  answer; it simply has the right spirit ."

— Douglas R. Hofstadter, 1985, Metamagical Themas: Questing for the Essence of Mind and Pattern  (Kindle edition, locations 11557-11572)

See also Many Dimensions in this journal and Solomon's Cube.

Sunday, September 29, 2019

Spiritual Kin

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

"The 15 Puzzle and the Magic Cube
are spiritual kin …."

— "Metamagical Themas"  column,
Douglas R. Hofstadter, Scientific American ,
Vol. 244, No. 3 (March 1981), pp. 20-39

As are the 15 Schoolgirls and the Eightfold Cube.

Saturday, May 11, 2013

Core

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

Promotional description of a new book:

"Like Gödel, Escher, Bach  before it, Surfaces and Essences  will profoundly enrich our understanding of our own minds. By plunging the reader into an extraordinary variety of colorful situations involving language, thought, and memory, by revealing bit by bit the constantly churning cognitive mechanisms normally completely hidden from view, and by discovering in them one central, invariant core— the incessant, unconscious quest for strong analogical links to past experiences— this book puts forth a radical and deeply surprising new vision of the act of thinking."

"Like Gödel, Escher, Bach  before it…."

Or like Metamagical Themas .

Rubik core:

Swarthmore Cube Project, 2008

Non- Rubik cores:

Of the odd  nxnxn cube:

 

Of the even  nxnxn cube:

 

The image “http://www.log24.com/theory/images/cube2x2x2.gif” cannot be displayed, because it contains errors.

Related material: The Eightfold Cube and…

"A core component in the construction
is a 3-dimensional vector space V  over F2 ."

—  Page 29 of "A twist in the M24 moonshine story,"
by Anne Taormina and Katrin Wendland.
(Submitted to the arXiv on 13 Mar 2013.)

Thursday, May 5, 2011

Beyond Forgetfulness

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

From this journal on July 23, 2007—

It is not enough to cover the rock with leaves.
We must be cured of it by a cure of the ground
Or a cure of ourselves, that is equal to a cure

Of the ground, a cure beyond forgetfulness.
And yet the leaves, if they broke into bud,
If they broke into bloom, if they bore fruit,

And if we ate the incipient colorings
Of their fresh culls might be a cure of the ground.

– Wallace Stevens, "The Rock"

This quotation from Stevens (Harvard class of 1901) was posted here on when Daniel Radcliffe (i.e., Harry Potter) turned 18 in July 2007.

Other material from that post suggests it is time for a review of magic at Harvard.

On September 9, 2007, President Faust of Harvard

"encouraged the incoming class to explore Harvard’s many opportunities.

'Think of it as a treasure room of hidden objects Harry discovers at Hogwarts,' Faust said."

That class is now about to graduate.

It is not clear what "hidden objects" it will take from four years in the Harvard treasure room.

Perhaps the following from a book published in 1985 will help…

http://www.log24.com/log/pix11A/110505-MetamagicalIntro.gif

The March 8, 2011, Harvard Crimson  illustrates a central topic of Metamagical Themas , the Rubik's Cube—

http://www.log24.com/log/pix11A/110427-CrimsonAtlas300w.jpg

Hofstadter in 1985 offered a similar picture—

http://www.log24.com/log/pix11A/110505-RubikGlobe.gif

Hofstadter asks in his Metamagical  introduction, "How can both Rubik's Cube and nuclear Armageddon be discussed at equal length in one book by one author?"

For a different approach to such a discussion, see Paradigms Lost, a post made here a few hours before the March 11, 2011, Japanese earthquake, tsunami, and nuclear disaster—

http://www.log24.com/log/pix11A/110427-ParadigmsLost.jpg

Whether Paradigms Lost is beyond forgetfulness is open to question.

Perhaps a later post, in the lighthearted spirit of Faust, will help. See April 20th's "Ready When You Are, C.B."

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