Archive for the ‘math’ Category

Seven, Eleven, All Good Children Go to Heaven


“Arithmetic is where numbers fly like pigeons in and out of your head.

Arithmetic tells you how many you lose or win if you know how many you had before you lost or won.

Arithmetic is seven eleven all good children go to heaven – or five six bundle of sticks.

Arithmetic is numbers you squeeze from your head to your hand to your pencil to your paper till you get the answer.

Arithmetic is where the answer is right and everything is nice and you can look out of the window and see the blue sky – or the answer is wrong and you have to start all over and try again and see how it comes out this time.

If you take a number and double it and double it again and double it a few more times, the number gets bigger and bigger and goes higher and higher and only arithmetic can tell you what the number is when you decide to quit doubling.

Arithmetic is where you have to multiply – and you carry the multiplication table in your head and hope you won’t lose it.

If you have two animal crackers, one good and one bad, and you eat one and a striped zebra with streaks all over him eats the other, how many animal crackers will you have if somebody offers you five six seven and you say No no no and you say Nay nay nay and you say Nix nix nix?

If you ask your mother for one fried egg for breakfast and she gives you two fried eggs and you eat both of them, who is better in arithmetic, you or your mother?”

— Carl Sandburg (, yo.)


Descartes on Rainbows


Forty-two degrees makes a rainbow, he says in the Dioptrics. But what is a rainbow if no one is looking at it?

To the vector belong the spoils

It’s a beautiful book, to be sure, but how fortunate we are that Chuck Jones met up with Norton Juster and made this mathy gem, which might actually surpass the bound version. Enjoy a famous love story, animated, entitled The Dot and The Line.

(Thanks, Centrepital Notion.)

The Sound of 1.5 Billion Heartbeats


There’s all kinds of interesting background info here, like quarter powers, allometric scaling, fractals, vascular fluid dynamics, and cellular efficiency, but the basic idea is that no matter whether you’re a blue whale or a bat, the average lifespan of most mammals is right around 1.5 billion thumpa-thumpas. You can use them up at a rate of 30 beats per minute (elephant) or 1000 (shrew), but you only get so many. I say “you” here in jest, because we humans just love to give Mother Nature the finger: a quick calculation based on a human heart rate of 70 bpm suggests that we should all be dead by 41. Good thing we invented soap, huh?