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Archive for the 'Uncategorized' Category

25 May

Pundits

TweetPaul Meehl's (1954) book Clinical Versus Statistical Prediction: A Theoretical Analysis and a Review of the Evidence appeared 25 years ago. It reviewed studies indicating that the prediction of numerical criterion variables of psychological interest (e.g., faculty ratings of graduate students who had just obtained a Ph.D.) from numerical predictor variables (e.g., scores on the […]

23 Feb

A First Look at "The Population Explosion" Book

Tweet The book in fact has a longer title: The Population Explosion and Other Mathematical Puzzles. The title warrants an observation. I once wrote of the difference in attitude of mathematicians and puzzlists to solving problems. While, for a puzzlist, solving a problem is a goal in itself, for a mathematician it may serve as […]

01 May

A wrapping surprise

As you may surmise, the path will behave - if I may say so - in a more rational way. Given the incommensurate dimensions of the box it was rational to expect an endless path. This is what you get on the second attempt. But there remains a question to ponder: Why was the first path so short? Jim Henle leaves to his readers to find the answer.

02 Apr

An impossible building, at least this is how it looks

I have very little time driving through Newark, NJ when I cauaght the site of the Panasonic building. It absolutely appears an impossible structure that reminded me of an old applet Structural Constellation one example of which you can see below

07 Oct

Review of "Zombies and Calculus" by Colin Adams

Tweet Colin Adams, author of the unique book "Zombies and Calculus", opens the book with a warning that "if you are squeamish you should not read the book." I venture an additional warning: if you lack a sense of humor, you should not read it either. As an afterthought, the author considers that, given the […]

01 May

Making Escher Proud - in Dance

Tweet Post by ‎Suzanne Dellal Centre מרכז סוזן דלל‎.

24 Apr

Environmental impact of power lines

This is to simply document my observation which I've been mulling over for a long time until very recently.

A couple of streets that I daily drive over are lined with trees whose branches seem to exhibit strange growth pattern. While their older branches point unremarkably each other way, the younger ones sprout pretty much vertically

29 Jan

Wizards, Aliens, and Starships

Truth be told, at the outset, when I realized what the book was about, I was a little annoyed. Science is science and fantasy is fantasy, and one may not want to know that there might be something wrong with the concepts in the book one is enjoying. Should everything be laid bare? That's literature we are talking about, for crying out loud, not textbooks or manuals! But Adler's writing is lucid and engaging and it sucks you in. There are so many whys and whats that I eventually developed a feeling that reality may be by far more interesting then any kind of fiction.

18 Jan

Kordemsky's Palindrome Problem

In his last book Mathematical Allurments (Matematicheskie Zavlekalki), published posthumously in 2000, he tells a story of a 7th grade girl who got tempted to solve that problem and found a solution, too. She informed Kordemsky that her solution was different from the one in the book. Kordemsky encouraged her to look further, for other solutions. Several of her classmates get involved in the search that eventually produced more than 120 solutions. I can imagine Kordemsky's delight in seeing his efforts at attracting young minds to mathematics being born fruit. The kids even came up with something unexpected: many of the numbers they came up lead to other solutions when some pairs of their digits get swapped.

15 Sep

An identity in radicals

This amounts to a cubic equation for x=a+b: x^3+3x-36=0. The sum of the roots of this equation is -3, their product is 36, and the sum of their squares is 0. The latter implies that two of these are complex conjugates, say, u ± iv and one is a real number w (that is supposed to be 3.)

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