Archive for January, 2011

Mandelbrot Video

January 3, 2011

I was thinking of all the things I meant to post in 2010, that I diligently saved, but that became less timely as time went on.  D’oh!  Crucial mistake, since it turned out the alternative was…blankness.

So I thought it might be fun, at least in a New Year Cleaning sort of way, to post them.  And I thought I should call it Ten Things I Meant to Post, But Didn’t Get Around to.  Except I’m not sure that there are 10, so this might be a Hitchhiker Trilogy kind of Ten.

Thing #1 was really Saturday’s post:  The fact that the subtraction principle in Roman Numerals evolved gradually and (really, like almost everything I think) with some back and forth.

And Thing #2 is this Mandelbrot video, which was passed along by a colleague (Thanks Betsey!) in October, only a few days after Benoit Mandelbrot’s death.  So in honor of the man and all that he did, here’s a tribute, prepared several years ago.  I hope he saw it and enjoyed it.

From Youtube:  “A music video for Jonathan Coulton’s song Mandelbrot Set by Pisut Wisessing made in Film 324: Cornell Summer Animation Workshop, taught by animator Lynn Tomlinson every summer for Cornell’s summer session, in the department of Theatre, Film & Dance.”

Roman Numerals…not quite so simple

January 1, 2011

Happy New Year!  And since the New Year is all about numbers (especially if you have come to look forward to Denise’s annual January 1 post on Let’s Play Math:  form all the integers from 1 to 100 using (exactly) the digits 2, 0, 1, 1 and common mathematical symbols), here’s a picture of a number that I meant to post in October November December.



Recognize this number?  Even though it’s not written as LIV?  This is from the 54th entryway to the Colosseum in Rome, which was built almost 2000 years ago when Roman numerals didn’t always use the subtraction property that we’re taught, where 4 is written as IV instead of IIII.

I found that to be interesting in and of itself, since I’d heard that the subtraction was a later addition but never witnessed it.  But what’s weird?  It wasn’t a sudden change.  Here’s the forty-fifth gate:


The subtraction principle was used with 40, just not with 4.  Which leads to a natural question:  what about gate 44?


I’m bummed that we didn’t get a better picture of this, but you can kind of see all four Is after the L.  Apparently, according to our usual font of knowledge, the reluctance to use IV is because that was the standard abbreviation for Jupiter’s name in Rome (IVPPTER), and this mixture of sometimes using four symbols in a row continued for more than a thousand years:  in the 1390 English cookbook The Forme of Cury (here on Project Gutenberg) the author still uses IIII [as in the Table of Contents, where Section IIII is rapes in potage] and there are also some IV for section numbers and references to Edward, though those might be later additions.

Published under GNU-FDL

And even 100 years ago [last year, in 1910], the Admiralty Arch in London uses MDCCCCX instead of MCMX in the inscription


(In the tenth year of King Edward VII, to Queen Victoria, from most grateful citizens, 1910).

So what does all this mean?  Nothing much, except that Roman Numeral Rules were maybe not quite as hard and fast as I once believed.