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Jacobian update 2

Yesterday
a comment was made to the Jacobian update post saying :

The
newest thing I heard was that the proof unfortunately was incorrect at
some point – The jacobian conjecture strikes again..?? Comment by Stefan
12/6/2004 @ 4:16 pm

Clearly I was intrigued and I
asked for more information but (so far) got no reply. Some people
approach me for the latest on this issue (I don’t know a thing about the
‘proof’ but if you do a Google on Carolyn Dean Jacobian this weblog turns up third on
the list and therefore people assume I have to know something…)
so I did try to find out what was going on. I emailed Harm Derksen who is
in Ann Arbor _and_ an expert on polynomial automorphisms, so if
someone knew something about the status of the proof, he definitely
would be the right person. Harm replied instantly, unfortunately with
sad news : it seems that the announced seminar on Carolyn’s proof is
canceled because an error has been found… For the moment at
least, the Jacobian conjecture seems to be entirely open again in two
variables (of course most people expect it to be false in three or more
variables).

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home jukebox


I am trying to put all our music onto one old iMac to make a
HomeJukeBox but ran into an annoying problem. I discovered a pile of 70
Audio-CDs which PD1 ripped away
from home (and more importantly,
away
from internet-access) so if you feed them to iTunes they
only display Track01, Track02 etc. that is, _no_ songtitles,
_no_ artist name, _no_ album information etc. making them
pretty useless for my purposes. Fortunately PD1 wrote on each CD the
Artist and Album names giving me at least a fighting chance to get all
information. Here is how I managed to do this without too much typing
(probably there are other and better methods around but as I am still
waiting for my copy of iPod and
iTunes Hacks
to arrive and as I am not the world most adventurous
person I prefer to stick with the first method I tried that
worked).\\r\\nI had a look at the huge collection of Doug's
AppleScripts for iTunes
and found on his 'internet-section'
the script CDDB Safari Kit v2.2.1 which he describes as
\\r\\n

These two AppleScripts, “CDDB
Safari” and “CDDB Tracks to iTunes via Safari”, assist
in finding and retrieving Album track names, Album, Artist, and Year
from Gracenote's CDDB website using Apple's Safari browser.

\\r\\nAs this is pretty much what I want, I downloaded
these 2 AppleScripts and put them into my
~Library/iTunes/Scripts folder (you probably will have
to create the Scripts folder) making them available from the Script-menu
in iTunes. \\r\\nNow, insert a CD and double-click on its icon in iTunes
so that its Track 01 Track 02 etc. appear in a separate window. Single
click on a Track to get it marked and then open the CDDB
Safari
script from the iTunes-script-menu. A pop-up menu
appears asking you what info you like to find. Click on Album or Artist
to mark them and then click on the highlighted Search
CDDB
button and Safari will take you to the Gracenote: Search CDDB site.
Fill in either Artist name or Album name and hit Search. If you are
lucky a list of all song-titles will appear or (in case their are
several options) a list of all relevant Artist/Album combinations from
which you have to click the relevant one and you will get the
songtitle-list. Go back to iTunes and open the CDDB Tracks to
iTunes via Safari
script again from the iTunes-script-menu. You
will be guided through the process : it will collect the song-titles and
ask you to use them or not and afterwards it will also ask you to add
Artist-Album-Year info as well, single click on all info you want to
include and press Yes and thank the Script for all its work. Close the
iTunes window and drag the CD icon (which now has the appropriate name)
to the desired playlist and all lost information is regained! There are
a few caveats : check whether the number of songtitles on the
Gracenote-page matches that on your CD and pray that PD1 has not made
her personal sublist of tracks… further some extremely alternative
CDs are not in the database (out of the 50 I tried so far only one
failed) and finally there seems to be a problem with French accents.

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Elkies’ puzzles

Noam D. Elkies is a
Harvard mathematician whose main research interests have to do with
lattices and elliptic curves. He is also a very talented composer of
chess problems. The problem to teh left is a proof game
in 14 moves. That is, find the UNIQUE legal chess game leading to the
given situation after the 14th move by black. Elkies has also written a
beautiful paper On Numbers
and Endgames
applying combinatorial game theory (a la Winning
Ways!) to chess-endgames (mutual Zugzwang positions correspond to zero
positions) and a follow-up article Higher Nimbers in pawn
endgames on large chessboards
. Together with Richard Stanley he wrote a
paper for the Mathematical Intelligencer called The Mathematical
Knight
which is stuffed with chess problems! But perhaps most
surprising is that he managed to run his own course on Chess and
Mathematics
!

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