# JOST A MON

May 8, 2011

## Carnival of Mathematics 77

Welcome, folks, to the LXXVII edition of the Mathematics Blog Carnival. We have a wide-ranging litany of articles, although - despite our best efforts - not seventy-seven of them. Still, quite a few to whet an appetite or three.

According to custom, we must start with the oddities of the number. Instead, we'll just intersperse the facts amongst the various articles.

77 is a deficient number.

Sol Lederman presents Curve stitching with Mathematica posted at Playing With Mathematica.
Meanwhile, does anyone remember the NBC adventure series 'The Tales of the 77th Bengal Lancers'?
Ever heard of curves with infinite perimeter and zero area? Read That's Impossible! One Giant Nerdgasm at Consumed By Wanderlust.
And, of course, Jesus of Nazareth is supposed to be of the 77th generation from Adam.
What does the Great Pyramid tell us about ancient Egyptian mathematics? Dave Richeson reveals an interesting consequence in Division by Zero.
77 is evil.
Alexander Bogomolny presents Areas on the Graphs of Power Functions posted at CTK Insights.
77 is also vile!
At Travels in a Mathematical World,  Peter Rowlett presents a collection of podcasts and videos from the Math/Maths Week 2010, and from Young Researchers in Mathematics 2011.
77 is the number of digits of the 12th perfect number. Somewhat uncannily, 77 also is the number of integer partitions of the number 12.
Mike Croucher ponders whether graphical calculators have outlived their usefulness at Walking Randomly.
77 is the sum of three squares, 42 + 52 + 62, as well as the sum of the first eight prime numbers.
Speaking of calculators, did you know you could multiply on your fingers? I didn't, but Math and Multimedia reveals some tricks.
77 is the atomic number of the element iridium. Does anyone remember Motorola's ill-fated ventured of the same name that was supposed to revolutionise global telecommunications?
While the little folk do elementary mathematics on their fingers, the powerhouses of the discipline get their breakthroughs at the most peculiar places and moments in time. Dick Lipton lists some of them in Godel's Lost Letter and P = NP.
77 is the largest number that cannot be written as a sum of distinct numbers whose reciprocals sum to 1.
Pat Ballew highlights the quotation 'old mathematicians don't die, they just go off on a tangent', and illustrates nicely the properties of tangents to a cubic at Pat's Blog.
77 is not a sum of two squares - but it is a sum of 2 squares!
At Short Sharp Science, Catherine de Lange reveals how tattoos (unsightly at the best of times, heheh) become even unsightlier with age. Mathematicians have developed a model that describes the aging of tattoos. (Do you think the picture below looks like a tattoo of 77? No? Dash it.)
And IT History has a little piece on the beginnings of computer user groups - all the way back in 1952!

Speaking of beginnings, it's the centenary of IBM. Take a look at this celebratory post at Antipodes: Reflections from an Australian Expatriate in France?

"Wannabe professional gambler" Zac mixes up probability and ethical humanism in his post Gambling Theory at Zac Sky.

SquareCircleZ ponders what is the correct graph of arccot(x)?

Alex Bellos discovers that there are more to triangle centres than he had previously imagined (and revealed to us in his book Alex's Adventures in Numberland).

Roice has some clever Geodesic Saddles.

And Joe Manausa shows how Tallahassee residents need to wait till 2018 for their house prices to return to equilibrium in his case study. Long time to wait, eh?

And just so that we Anglospeakers don't feel too alone, we are pleased to reveal that the Spanish blogosphere has its own Carnival of Mathematics. The latest installment is by Juan Martínez-Tébar Giménez at Los Matemáticos no son gente seria, and it showcases entertaining pieces on, among a couple of dozen other things, Tartaglia and Cardano, the Nash conjecture, the decipherment of a wartime diary, and the centenary of the Royal Spanish Mathematical Society.

That's it for this month, people. Please do take a look at our sister carnival - Math Teachers at Play -  and also note that you can follow the Carnival of Math on Twitter: @Carnivalofmath. The next Carnival of Mathematics should come up around Jun 3, 2011. Please send in your submissions here.

Guillermo Bautista said...

Excellent collections. Thanks for including my post.

Fëanor said...

No, no, thank you!

Peter Rowlett said...

Hi, Thanks for including me but my name is misspelled as Rowlatt not Rowlett, "podcasts and videos from the Maths Week 2010" should be "Math/Maths Week 2010" and the link for that text goes to blogger.com when it should go to Audio and video content produced during Math/Maths Week 2010.

Fëanor said...

Peter: sorry about that, corrected now.

Juan Martínez-Tébar Giménez said...

Thanks for the reference. Great Job

Peter Rowlett said...

Thank you! :)