johnkemeny.com

Welcome to the 15^th Carnival of Mathematics.  While the quantity is low during these doldrum months, I think the quality of this episode is excellent.  The contents also speak to the question du Jore of whether the CoM should be bifurcated into separate teaching and research Carnival?  We actually have a research contribution that is explainable in elementary terms and has everyday application – if you eat McNuggets everyday (not recommended)! 

But before that, because I surely will be asked (again), let me point out I-am-only-related-by-name-to-the-late-famous-Professor-John-G-Kemeny.  My favorite anecdote about him is when he was appointed President of Dartmouth he requested to continue teaching.  The Board thought that was beneath the position.  So he asked what they would say if he requested time to play golf.  He got to teach.

My father-in-law, Bill Curnin, is a retired professor, and pointed out a Brief History of Mathematics, which he has used in the classroom since 1948.  While there I noted the 1954 poem A Song … Against Mathematicians which begins:

Of all the lunatic professions which are practised on this earth
Mathematics is the craziest, and has been from its birth.

I thought to enlarge upon this in poet laureate style:

I must read and study math again, where tensor algebras Lie,
And all I need is a Kronecker delta, an epsilon and pi;

I immediately realized I wasn’t up to the poetry nor math – so you’ll have to bear with my limericks.

Chapter 1: 3599..

Taking pairs from the number nine closet,
And appending to 35, I’ll posit,
When factoring’s done,
Some 6*10^N plus one,
Is a divsor. The results’ all composite!

In Teaching Factoring – Should we?, Jonathan (aka jd2718) kicks off a series of 4 articles on rationales for what we should teach our children.  In the second article published today, I ban FOIL, he explains how his school handles polynomials to make factoring easier.  The next article will be on the trinomial factoring technique, breaking the middle.  Jonathan says, “It’s not uncommon, but many people have never seen it.”  The last article will cover other sorts of factoring and anecdotes.  For reference, there are internet discussions on factoring, and/or you can just do communal factoring on your PC.

Chapter 2: A tale of five gentlemen

Henricus Hubertus van Aubel (1830-1906), was a Dutch mathematician who proved a pretty theorem on quadrilaterals.  A. Gutierrez has a javascript conventional proof, accompanied by Chopin, online.  Wesley Cowans of FOXMATHS! did one better. His proof of van Aubel’s theorem uses complex numbers instead of standard geometric techniques.

 This problem has an interesting history.  It is related to a theorem attributed to Napoleon, often called the most rediscovered theorem in mathematics.  

A generalization of both theorems is attributed to three men, Karel Petr, Bernhard Newmann, and Jesse Douglas (proof and interactive gizmo by Alex Bogomolny).  Petr (1868-1950) was a high-powered Czech math professor before, during, and after two World Wars – with many students-turned-refugees.  Newmann has a history with Napoleon’s Theorem explained in an Australian interview entitled Napoleon, my Father and I. Douglas, co-winner of the first Fields Medal, working independently (pdf) at the same time as Newmann (1939-1941) had an incredibly prolific year in 1939.  He is also a fellow Bronxite.  Of course, as Stephen Gray points out in his 2002 article Generalizing the Petr-Douglas-Neumann Theorem on n-gons (pdf), Petr has precedence, publishing in 1908!  

Chapter 3: Pay me now or and pay me later 

John Armstrong, the Unapologetic Mathematician, tackles a solution to an actual, real-world  data analysis problem, CEO Compensation and its relationship to corporate profits. What relationship? John has been in an Ivory Tower too long. Read Dilbert. (just kidding – actually a thoughtful article)

 

 

 

Chapter 4: Study now or and study later

Dave Marain at MathNotations sent in How Recursion is Tested on the SATs and much more… Designed for middle- and high schoolers, this detailed investigation for the classroom explores the ideas of recursive-defined sequences using an SAT-type problem as a springboard.

That’s my son Alan studying at the blackboard. He should be ready for SATs in about 15 years.  I wonder if they will have changed much, viz., no portable AI-bots in the exam room?

 

Chapter 5: 26³

Julie Rehmeyer reports some news about advances in solving Rubik’s Cube in Cracking the Cube in MathTrek. Northeastern professor Gene Cooperman and grad student Dan Kunkle have discovered a way, using high-powered computation, to reduce the maximum number of moves to solve the puzzle by 1, to 26. However, there is room left for improvement, as it is believed that 20 moves may be the minimum. If that’s too simple, here is an online 4D Magic Cube to play.

Julie also writes an interesting article on mathematically modeling word acquisition in Calculating the Word Spurt.

 

Chapter 6: 43 McNuggets to don’t go

A student of Shalit’s named Xu,
Discovered some math that is new,
There are Frobenius things,
Taken from co-finite strings,
Constructed so they exponentially grew.

Here is the fresh research article, The Noncommutative Frobenius Problem is Solved!, from professor Jeffrey Shalit at Recursivity.  It is well explained, and the tie-in to McNuggets is delicious.

Chapter 7: For Smarties Only, NOT!

Secret Blogging Seminar is a group blog by 8 recent and future Berkeley mathematics Ph.D.’s. Sound intimidating?  Not always.  Take, for example, Scott Carnahan’s piece p-adic fields for beginners.  You could learn something.  Then there is Noah Snyder’s The Minkowski Bound. Not frivolous!

The following rating system I devised, analogous to the movie rating system (G, PG, PG-13, R, NC-17), should help you identify appropriate articles:-)

• γ = Graduate Level
• Ï€ Γ = Post-Graduate
• Ï€ Γ – XIII = 13-year old Post-Graduate
• ρ = Rudimentary
• ν Χ – XVII= Nearly Comatose 17-year old

Epilogue: Off to the movies

That’s where I’m going.  But you should stay and exercize your brain here (thanks Alvaro Fernandez & Praveen).  Oh, I wanted to congratulate Sherry Gong, from Exeter, N.H., who earned a gold medal and tied for first place at the 2007 China Mathematical Olympiad for Girls, which was held in Wuhan, China, from August 11-16.

 

That’s right, on 24-August I will be publishing the 15^th CoM.  Right again, Alon mispelt the name of the blog, substiuting ‘blog’ for ‘bog’ in a mispelt bog, which is just irony (pun intended).

Anyway, send your entries to the Carnival through here or direct an email to johnkemeny at yahoo dot com.  It would be helpful to include ‘Carnival’ or ‘CoM’ in the subject line.

First EMC competitor, Hitachi, publishes an attack ad video starring Mr.(“M” as in “Mister”) T.  Now EMC is doing viral video marketing at fun with tape starring Bob + Joe.  Is that a chocolate mustashio on Bob that harkens back to the California Milk Board’s Got Milk? campaigns by GS&P, namely, cow abduction and the insanely elaborate planet in need? With milk prices at record highs, about the same per gallon as gasoline, which does nothing for strong bones (nyuk, nyuk, nyuk), the real question is Got Cash?

Update: A new Hitachi attack video starring Mr. T is out on youtube.

 

As reported by the BA, the Space Shuttle (STS-117) and the International Space Station (ISS) are flying tandem, and should be visible from Westford tonight 9:17 through 9:24 pm (details at heavens-above, btw., Distan=distance in km).  Unfortunately, the cloud cover is predicted overcast here.  But if it is clear where you are, look up! You won’t even need binoculars.

You may have noticed the column of web widgets in the sidebar on your right.  Eaton Web – The Blog Directory is one of them.  When I signed up I thought it was another blog stats counter like so many others.  But they actually have a human look at your blog and write a review (or they have a great AI program that even mispells).  They said some nice things, so I thought I’d bring it up.

Let me be the ~20,000^th blog (here, here, here, here, slashdot) to moan the death of the great Don Herbert (NY Times obituary) just shy of his 90^th birthday.  We celebrated his 89^th here in this blog.  Thank you Mr. Wizard (official website).

 

An MIT research team reported last Thursday in Science Express (pdf available to Science subscribers) a novel method for transmitting power through the air.  They are calling it WiTricity (pronouned “why” not “we” – why?), and there is a web site (witric.com) to follow events. It reports the spectacular rise from zero to over a million google results in the last 5 days.

Sending power through the air is certainly not new.  It goes back at least to Nikola Tesla’s coils, which you can buy from Resonance Research if you are a science museum.  But they aren’t safe!  At high frequency high voltage your body’s nerves will not register a painful ZAP from the sparks – but damage to cells can occur.  Indeed, Tesla coils have been the basis for death rays. WiTronics uses magnetic fields to transmit power.  This has been studied extensively, since it is used in the medical procedure MRI, and is much safer.

Safety aside, the other innovation is using resonance to efficiently transmit the power.  Without resonance the power would either dissipate in all directions, or need to be focused in a direct line of sight to the target device.  Resonance allows the target device to selectively pluck power from the air, while intervening objects would not be affected.  A prototype can transmit 60 watts across 2 meters with people in the airspace between the devices (see picture)…miniaturization TBD.

Tonight is the second full moon of the month.  In 1946 Sky & Telescope magazine mistakenly created the myth that this moon is called a blue moon.  They have recently corrected that to say what the Maine Farmer’s Almanac really said – that the third full moon in a season with four full moons is called blue.  The almanac picked that nominalism simply because they needed an extra name.  After all, the monthly full moons all had a name:

• January – Wolf moon
• February – Ice moon
• March – Storm moon
• April – Growing/Flower moon
• May – Hare moon
• June – Mead moon
• July – Hay moon
• August – Corn moon
• September – Harvest moon
• October –  Hunter’s moon
• November – Snow moon
• December – Winter moon

But sometimes the moon really appears blue, like on May 20-21 in Hungary when fine dust from the Sahara desert blew over the country.  Ágnes Kiricsi, whose Hungarian/English blog is Atmospheric Optics (not to be confused with the UK’s Atmospheric Optics website), captured the scene over Budapest.  Her friend, Noli, captured an equally rare event with the same cause, a solar Bishop’s ring as well as an iridescent cloud (which has nothing to do with Saharan sands, but is very pretty).