This item is a postcard announcing The Book of Why, by Judea Pearl and Dana Mackenzie, a book to be published in May 2018 by Basic Books. This book confronts the hoary old adage, "Correlation is not causation," which has been taught to generations of…
An overview of an old magic trick called "The Animal Hunter", how it has appeared throughout my life, and an example of an idea how someone could apply it for their own use.
A zometool-based geometrical model/puzzle based on the 13-zone system, i.e., 3 blue lines, 4 yellow lines and 6 green lines, which are associated with the face centers, vertices and edge centers of the cube.
A small booklet of 20 math puzzles that involve the element of surprise. Some appear to lack sufficient information to solve; others run counter to one's intuition as to what the answer should be.
Sudoku Ripeto and Custom Sudoku are the first Sudoku variants with repeated numbers and letters (please visit www.customsudoku.com). As such, they require new solving tricks and techniques.
I am glad to offer an assortment of books featuring…
Space Chips are a versatile building toy. With the same chips you can build 3D shapes that are symmetrical, or you can build 3D characters that are expressive and creative.
My contribution to the gift exchange is a 5 X 7 inch, four-color, tri-fold glossy card with photographed imagery of my 11 X 12 X 9 inch multifaceted-portrait-sculpture of Martin Gardner. My painted, kiln-fired, stained glass and…