[next] [prev] [up] Date: Thu, 11 Jun 92 17:39:00 -0400
[next] [prev] [up] From: Allan C. Wechsler <ACW@riverside.scrc.symbolics.com >
[next] [prev] [up] Subject: Name query.
Date: Thu, 11 Jun 1992 16:52 EDT
From: Guy Steele <gls@think.com>
From: ronnie@cisco.com
Date: Wed, 10 Jun 92 12:11:35 PDT

>Can anyone tell me:-

>Why is the "Pons Asinorum" pattern so called ?

Pons Asinorum is Latin for "Asses' Bridge," and is the name of the
proposition that the base angles of an isoceles triangle are equal.
It is more generally any test of ability imposed upon the inexperienced
or ignorant.

The term also carries the connotation that the test is in fact
of the simplest and most elementary kind. If you can't prove
the Pons Asinorum of geometry, then you don't know even the most
elementary concept of geometry--i.e., as a geometer, you know as
much as a donkey. And if you cannot form the Pons Asinorum
pattern, you sure don't know much about cubing.

--Guy Steele

I think the metaphorical leap from geometry to cubing was probably made
by Bernie Greenberg, in whatever year it was that Hofstadter did his Sci
Am column. Hofstadter came to MIT to talk to a bunch of cubers,
gathering material for his article. I was in the group and my name is
mentioned in the article -- the only time I have ever gotten my name
into Sci Am.

"Pons Asinorum" has a lot of Bernie's style about it -- casual use of
Latin, whimsical metaphor, fondness for naming things. He had a bunch
of cube operators with Latin names, and also some wacky English ones. I
remember the Spratt Wrench (F R'L D R'L B R'L U R'L) which flips four
edges and was what everyone used before monoflips were discovered.
Bernie also had things with names like the Lesser Hammer of the Right
and the Greater Hammer of the Right; his "patter" was fabulous. I
regret not having a videotape of Bernie solving the cube in, say, 1978.
(I hope I've got the year right.)

While I'm reminiscing, I should confess that my standard corner operator
is still the same as it was then: (FUR)^5, which exchanges two corners,
leaves the rest of the corners alone, and fucks the edges completely.
(Prudes, do not hassle me. This has been a technical term in cubing
around MIT since The Beginning.) Because of this property of "furry
five", I have to home and orient all the corners first, before I touch
the edges. It's the kind of quirky algorithm you don't see among
younger cubers, because everybody these days learns how to solve the
thing from a book. In the Beginning, there were no books, and I proudly
state that I solved the cube from scratch, by brainpower. Later I
discovered that there were easier ways to do things than (FR)^105! I
had pages and pages covered with little cube diagrams with arrows
showing how the stickers were permuted by a particular sequence.

I'm interested in hearing other reminiscences from people who actually
solved the cube -- you're disqualified if you learned how to solve it
from somebody else, or from a book.

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