Tuesday, April 01, 2014

Pythagorean Legends, Pythagorean Triples

The Pythagoreans were a secret society in ancient Greece, a mystical brotherhood dedicated to mathematical study. Their motto was "All is number." Esoteric groups such as the Freemasons and Rosicrucians claim descent from the Pythagorean Brotherhood.

The central assumption of the Pythagorean brotherhood was that the entire universe could be explained by careful application of whole numbers or their ratios (i.e. fractions, or rational numbers). Legend has it that when a member of the cult of Pythagoras proved that even something as simple as the diagonal of a square could not be measured using whole numbers or their ratios, he was summarily executed to avoid insulting prevailing Pythagorean doctrine.

Nevertheless, Pythagorean theories have been applied over the centuries to such diverse problems such as building the great pyramids of Egypt, establishing musical scales, and mapping the orbits of planets.

The good ol' Pythagorean Theorem is one of the most fundamental formulas in all of mathematics. Falsely attributed to Pythagoras of Samos, this famous rule defines the relationship between the lengths of the sides of all right triangles:

a^2 + b^2 = c^2.

Pythagorean Triples are trios of whole numbers that conform to the requirements of the Pythagorean Theorem, and therefore measure the three sides of a right triangle: the two "legs" forming the right angle, and the "hypotenuse" (not "hippopotamus") opposite the right angle.

Here's a fun and simple way to generate Pythagorean Triples from any given natural number (indeed, all Pythagorean Triples can be generated this way):

1. Pick a natural number larger than two. Call this number n.

2. If n is even: let y be 1 and let x be half of n; otherwise (if n is odd) first subtract 1 from n, then let y be half of this new number and let x be one more than y.

3. The following equations will generate Pythagorean Triples for any such x, y:

a = x^2 – y^2

b = 2xy

c = x^2 + y^2

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Copyright © 2006-present: Christopher R. Borland. All rights reserved.

Saturday, March 01, 2014

Car Talk Puzzlers

NPR's uproariously funny Car Talk could be the single funniest thing on radio. On more than one occasion it was all I could do to maintain control of my car as I listened to the hilarious rantings of Tom and Ray Magliozzi, better known as "Click and Clack ... the Tappet Brothers," during their weekly automotive question and answer show (to get an idea, check out the current list of Car Talk staff members, presumably vetted by the show's ace legal firm: "Dewey, Cheetham, and Howe").

Far from being among the dimmer bulbs in the lamp, these grease monkeys are actually scientists with MIT degrees, no less. A featured part of each broadcast is the weekly "Puzzler," and a fair number of these fabulous brain twisters are mathematical rather than automotive in nature (here's where the guys show their MIT roots).

Click here for an archive of Puzzlers from past shows ... or here to buy a recently published collection of favorite Car Talk Puzzlers at amazon.com for as little as $.01 plus S & H!

To listen to Car Talk (online, NPR affiliate station, Sirius Satellite Radio, podcasting, etc.), click here.

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Copyright © 2006-present: Christopher R. Borland. All rights reserved.

Saturday, February 01, 2014

Finite Simple Group (Of Order Two)



Whoever said math isn't musical has never heard The Klein Four.

If you've got a couple of minutes, take a break, give yourself a treat, and check out this hilarious, cleverly written, well performed a cappella composition:

Finite Simple Group of Order Two

Although knowledge of group theory isn't at all required to enjoy the performance, the brilliant plays on words that comprise the lyrics will make real sense only to those with some knowledge of higher mathematics.

Here they are:

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Finite Simple Group of Order Two

The path of love is never smooth
But mine's continuous for you
You're the upper bound in the chains of my heart
You're my Axiom of Choice, you know it's true

But lately our relation's not so well-defined
And I just can't function without you
I'll prove my proposition and I'm sure you'll find
We're a finite simple group of order two

I'm losing my identity
I'm getting tensor every day
And without loss of generality
I will assume that you feel the same way

Since every time I see you, you just quotient out
The faithful image that I map into
But when we're one-to-one you'll see what I'm about
'Cause we're a finite simple group of order two

Our equivalence was stable,
A principal love bundle sitting deep inside
But then you drove a wedge between our two-forms
Now everything is so complexified

When we first met, we simply connected
My heart was open but too dense
Our system was already directed
To have a finite limit, in some sense

I'm living in the kernel of a rank-one map
From my domain, its image looks so blue,
'Cause all I see are zeroes, it's a cruel trap
But we're a finite simple group of order two

I'm not the smoothest operator in my class,
But we're a mirror pair, me and you,
So let's apply forgetful functors to the past
And be a finite simple group, a finite simple group,
Let's be a finite simple group of order two
(Oughter: "Why not three?")

I've proved my proposition now, as you can see,
So let's both be associative and free
And by corollary, this shows you and I to be
Purely inseparable. Q. E. D.

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Copyright © 2006-present: Christopher R. Borland. All rights reserved.

Wednesday, January 01, 2014

Study Buddies!

One of the best things you can do to improve your chances of success in a given class is also one of the most fun.

"Study Buddies" are people you meet and with whom you agree to form informal academic partnerships in each course you're currently taking. Not only will these relationships help you make sure you make it through the course successfully, they can also add to your social life!

As a new semester begins, find two people in each class, fellow students you like who seem to share your particular standards and interests, and exchange contact info (phone, email, etc.) with them. Now, if you miss class and need information about homework, an upcoming test, lecture notes, etc., you have two people you can call (if one isn't available, the other probably will be).

Study Buddies may even choose to go beyond occasional contact to form more formal study groups that meet before important tests to go over course material and help answer each others' questions, work together on group projects, etc.

Forging and utilizing these alliances can result in better grades, reduced stress, and enhanced involvement and participation in class, while providing a safe and productive way to make contact with other students you'd like to meet and get to know better.

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Copyright © 2006-present: Christopher R. Borland. All rights reserved.

Sunday, December 01, 2013

The I Hate Mathematics! Book

I came across this little gem back in the early days of my private teaching career nearly 30 years ago (I still have my original copy), and it remains one of my very favorite books for students young or old who struggle with math phobia or maintain an abiding hatred for the subject.

Combining author Marilyn Burns's witty writing with engaging illustrations, jokes, activities, and explanations, this wonderful book celebrates the "other" side of mathematics – the creative, beautiful, quirky, fun side hidden from a great many unfortunate students.

This is not an instructional text, at all. Rather, it's a funny, fascinating exploration aimed to crack the fearful shells of the math phobic and blow the minds of math haters everywhere.

The I Hate Mathematics! Book should be required reading for all young students and others who wish math would just "go away." After any serious reading of this short work, it's difficult to believe that math is hopelessly beyond one's grasp, or to retain a complete lack of interest in the subject (much less an thorough contempt for it). Parents should buy this book, read it themselves, and then read and discuss it with their youngsters who display any signs of serious aversion to mathematics.

The only improvement I could suggest would be to strike through the word "Hate" in the title and replace it with the word "Love," as I did with my original copy – such is the unexpectedly powerful, positive effect this book can have on its readers.

Recommended for ages 9-12.

Find it on amazon here, and archived here.

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Copyright © 2006-present: Christopher R. Borland. All rights reserved.