November 2007 - mathfun@mailman.xmission.com

[math-fun] re: octothorpe: M-W's Word of the Day
by Steve Witham 10 Nov '07

10 Nov '07

"Can we simply just say, Ere it spoils your day, It's the thorp between seven and nine?" Cool, a limerick reverse-engineering puzzle. Da dada da dada da dine Da da dada da da number sign, --Steve

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[math-fun] octothorpe: M-W's Word of the Day
by Marc LeBrun 09 Nov '07

09 Nov '07

A friend forwards the following, which has been discussed here. I hadn't heard the partial limerick at the end before... ======== The Word of the Day for November 9 is: octothorpe \AHK-tuh-thorp\ noun : the symbol # Example sentence: Barry noticed the pound sign on the telephone and remarked about how much the octothorpe resembled a tic-tac-toe grid. Did you know? Stories abound about who first called the # sign an "octothorpe" (which can also be spelled "octothorp"). Most of those tales link the name to various telephone workers in the 1960s, and all claim the "octo-" part refers to the eight points on the symbol, but the "thorpe" remains a mystery. One story links it to a telephone company employee who happened to burp while talking about the symbol with co-workers. Another relates it to the athlete Jim Thorpe, and a third claims it derives from an Old English word for "village." If the plethora of theories leaves your head spinning, you might want to take the advice of the wag who asked (poetically), "Can we simply just say, / Ere it spoils your day, / It's the thorp between seven and nine?"

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[math-fun] November news of multimagie.com
by Christian Boyer 06 Nov '07

06 Nov '07

The November 2007 update of www.multimagie.com/indexengl.htm is now online, with a lot of news. Including details on solutions briefly announced through [math-fun]: -the Wroblewski-Pfoertner's squares, one of them solving the Open problem #6 published in The Mathematical Intelligencer in 2005. A direct access to their squares: www.multimagie.com/English/WroblewskiPfoertner42&44.htm -solution E 496 published in the October 2007 issue of The American Mathematical Monthly (but more detailed in my site). A direct access to the PDF file: www.multimagie.com/SmallestTriangularExpanded.pdf They published the problem 66 years ago. As they title: "Better late than never!"... Christian.

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[math-fun] An honor for a math-funner
by Dan Asimov 05 Nov '07

05 Nov '07

>From the October, 2007 American Mathematical Monthly: << E 496 [1941, 699]. Proposed by R.V. Heath, New York, NY. What is the smallest value of n for which the n^2 triangular numbers 0,1,3,6,10,...,(n^2)(n^2-1)/2 can be arranged to form a magic square? Solution by Christian Boyer, Enghien les Bains, France. The answer is . . . . . . . . . [Editor's note: In 66 years, no other solutions were received.] >> --Dan P.S. Solution is omitted in case anyone wants to work on this, though I suspect this problem has already been discussed here. (Has it?) P.P.S. Does anyone know of a longer interval between the publication of a Monthly problem and the first solution received?

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[math-fun] Re: Google books / "text behind image"
by Steve Witham 05 Nov '07

05 Nov '07

>From: Henry Baker <hbaker1(a)pipeline.com> >However, since both the ascii text & PDF images are available, >someone could easily automate the task of creating such PDF/text >files -- even someone outside of Google. You may be able to OCR the pdf files using the online DejaVu converter, assuming there aren't protection bits that some part of the converter gits skeered at: http://any2djvu.djvuzone.org/ Maybe you could then automate the process of correcting the embedded text in the djvu from the ascii from Google. A possible added benefit is that djvu format is much more compact than pdf. On the other hand, the reader for it (at least for the Mac) isn't so nice. Also, the default compression settings don't always seem to do the right thing about distinguishing foreground from background in illustrations. A simpler trick: maybe the page numbers are in the ascii? --Steve

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[math-fun] Re: Google books / "text behind image"
by Steve Witham 04 Nov '07

04 Nov '07

>From: Henry Baker <hbaker1(a)pipeline.com> > >I tried searching the downloaded PDF document for Tait's >Quaternions, but nothing was there. So it appears that Google isn't >using "text behind image", at least not for this book. However, >since both the ascii text & PDF images are available, someone could >easily automate the task of creating such PDF/text files -- even >someone outside of Google. I downloaded the PDF and submitted it to any2djvu.djvuzone.org, and got a converted .djvu file, but without text behind, even though I specified OCR in the entry form. So, that path isn't working for now. I don't know whether it's a technical issue, a protection-bits issue, or a web server problem at djvuzone. The usual progress log didn't come out, so I don't have any error messages (I emailed them about it). The image compression is pretty nice. 2.9 vs. 9.7MB. The type, equations and line drawings are excellent. The faint scribbles left by readers, which are, say, "thresholdy" in the pdf, are slightly more thresholdy in the djvu. There first page of the publisher's catalog in the back has a couple stains. Text quality over the stains is as good in the djvu as pdf. The cover, opening pages and closing pages have a couple places with dark sections with writing, which are definitely blurrier in the djvu. Djvu has a concept of "background" which is converted with lower resolution; it sometimes makes the wrong decision if you don't hand-tweak it. The viewer I have (MacDjView) scrolls a lot faster through the document than Adobe Reader and Preview do through the pdf. DjVu ought to be included into the pdf standard as a codec. --Steve

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Re: [math-fun] Re Shortest Successful Maths PhD Thesis
by Dan Asimov 04 Nov '07

04 Nov '07

Guy wrote: << Thanks Dan, Steve ... see: http://www.jstor.org/view/07468342/sp060005/06x0043q/6?frame=frame&userID=8… >> Thanks, Guy . . . BUT I was unable to get to any specific JSTOR page despite trying about 6 times to ensure that the string you sent occurred consecutively as it ought. (Just got the generic JSTOR login page, without any journal page or article mentioned.) --Dan

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[math-fun] Re Shortest Successful Maths PhD Thesis
by Guy Haworth 04 Nov '07

04 Nov '07

Thanks Dan, Steve ... see: http://www.jstor.org/view/07468342/sp060005/06x0043q/6?frame=frame&userI D=86e101a1(a)reading.ac.uk/01c0a8486a0050586c8&dpi=3&config=jstor guy

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Re: [math-fun] The shortest successful Maths Ph.D. theses
by Dan Asimov 04 Nov '07

04 Nov '07

Guy asks: << Apologies if this has been asked before. I'm wondering what have been the shortest successfully submitted Ph.D. theses in mathematics. >> Urk, mine was pretty short -- just 28 double-spaced typewritten pages. Google claims there's something about this in the Nov. 2003 College Mathematics Journal, which I don't have access to at the moment. (Can someone please get ahold of that and report what it says on the subject?) On the other hand, someone claimed on some discussion board that (presumably William Rowan) Hamilton's Ph.D. thesis was only one page long. --Dan

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[math-fun] The shortest successful Maths Ph.D. theses
by Guy Haworth 04 Nov '07

04 Nov '07

Apologies if this has been asked before. I'm wondering what have been the shortest successfully submitted Ph.D. theses in mathematics. Guy

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