Material added on Martin Gardner's Centerary
- My poem for the Wolfram Blog
For today’s magic show:
A century ago,
Martin Gardner was born in Oklahoma.
He philosophized for his diploma.
He wrote on Hex and Tic-Tac-Toe.
The Icosian game and polyomino.
Flexagons from paper trim,
Samuel Loyd, the game of Nim.
Digital roots and Soma stairs,
mazes, logic, magic squares.
Squaring squares, the golden Phi.
Solved the spider and the fly.
Packing circles (with corrections),
ellipses, pi, and conic sections.
- More on Martin Gardner
- From the New York Times, The Guardian, BBC News, Randi.org, maa.org.
Material added 7 October 2014
- Vacation Over
- Time to get back to this. Will try to have at least three items a day for awhile as I plow through the backlog.
- OEIS turns 50
- Neil Sloane's OEIS turns 50. OEIS.org turns 50, and Alex Bellos writes it up in the Guardian as Neil Sloane: the man who loved only integer sequences. But that's not true, Neil loves lots of things, like lattices and sphere packings.
- George Sicherman: I have not found any 5x5 pentapent solutions, but we can use the 7 tetrapents to make two congruent 28-pents, providing that we use one of the tetrapents in both figures. This figure is unique, but the tiling on the left is not.
- TheMetagrobologist Magazine
- TheMetagrobologist Magazine is a very snazzy only magazine devoted to puzzles.
- Covent Garden Floating Market
- A very nice illusion of a floating building.
- The mate-in-n problem of infinite chess is decidable
- The mate-in-n problem of infinite chess is decidable -- a new paper at arXiv.org.
- Pangrammic Top Ten
- Eric Harshbarger notes that last weeks top ten movies made a pangram.
- Martin Gardner Centennial
- Martin Gardner's 100th birthday is a few weeks away. Scientific American starts off the celebration.
Material added 20 March 2014
- Pentahex Holes
- George Sicherman - This weekend Abaroth sent me the attached picture of the 22 pentahexes. It has 33 holes, and is symmetric too. According to Andrew Clarke's Poly Pages, the old record was 30 holes.
- Toshihiro Shirakawa Polyboxes
- Toshihiro Shirakawa has found a number of new polyboxes.
- Hamiltonian Circuit for Rubik's cube
- A Hamiltonian solution for Rubik's Cube is known.
- Seven, Eight, and Nine Touching Cylinders
- Peter V. Pikhitsa1 and Mansoo Choi have a new paper, Seven, eight, and nine mutually touching infinitely long straight round cylinders.
- INCOME TAX FORM LOGIC PUZZLE
- Mark J. P. Wolf (from my work-in-progress book, 101 Enigmatic Puzzles)
Within the new Short Form 1, there is a loophole; with just the right amount of income, you don’t owe any tax at all. Find the one income amount that will result in zero tax owed when the tax form below is filled out. (docx answer)
- Recent Anagrams
- Arlo Guthrie's The City of New Orleans = Steel light train confers "How are you?".
I Have No Mouth And I Must Scream = A dour time to humans vs. machine.
Captain America: The Winter Soldier = WARipedia historical reenactment.
American Institute of Bisexuality = Caution: extreme unsatisfiability.
Christopher Nolan films esoteric ~ techno-thriller for space mission.
Worst-Case Scenario Handbook = Coordinate Seahawks-Broncos.
Electrochemical fluorination = Lime in the coconut for all I care.
Blockbuster motion picture = Put trust in comic book rebel.
Money is the root of all evil = Some love the irony of it all.
Let's run it up the flagpole = Telling "put up for the sale."
Institutional researcher = "In the literature" narcosis.
"A Tribute to Heroes" = He's about to retire.
Hi, G. Washington! = How's it hanging?
Crimea votes to ~ act more soviet.
Interest group = Peers tutoring.
- Heesch-2 Polyomino
- Glenn Rhoads found the minimal Heesch 2 polyomino in his 2003 thesis "Planar Tilings and the Search for an Aperiodic Prototile". I haven't seen it elsewhere, so here's a picture:
- Minimal Superpermutations
- 123412314231243121342132413214321 has all permutations of "1234", and is minimal. The shortest string for "12345" is unknown. These are called minimal superpermutations, and much harder to find than DeBruijn sequences.
- Oskar Interview
- An interview with Oskar is up, you can also head to Oskar's website, or Oskar's youtube channel.
- George Sicherman -- Here is a little puzzle that I call the Vixelstar. Just put the pieces on the left together to make the star-shaped figure on the right. You may flip pieces over. Also, these pages were all added recently to Polyform Curiosities: Zucca's Challenge Problem for Tetracubes, Pentacubes in a Box, Galvagni Figures & Reid Figures for Polycairos, Tetrahendec Oddities, Pento-Pento-Trominoes, Pento-Pento-Tetrominoes, Quadruple Pentominoes, and Printable Polycairo Grid.
- Similar Pentomino Shapes
- Livio Zucca: Odette De Meulemeester, George Sicherman and I are trying minimal solutions for each Pentomino, such as the type in the picture.
- Paths Through a Square
- Take 12 points around a square, with points in the corners and 4 points on each side. Join up the points with 6 lines, with no lines connecting points on the same side. The correct answer is 200 ways to do it. If mirror symmetries are removed, then there are 121 ways to do it.
- Top cited Math Papers
- Here's a list of the top cited math papers of all time.
- Attractive Attractors
- I liked this gallery of chaotic attractors.
- The Gentle Art of Filling Space
- A new book about the tiling patterns of Robert Reid is available.
- How to Tie a Tie
- How to knot a tie -- 177,147 distinct tie knots.
- Weird Paper Sculptures
- By making a huge stack of accordion-joined paper and then chiseling a bust out of it, surprisingly flexible heads can be made.
- Longest Entertainment Assemble?
- Star Trek original cast -- 25 years.
Jack Benny and Eddie "Rochester" Anderson -- 28 years.
Cheech and Chong -- 33 years.
Carson and McMahon -- 34 years.
Tom Baker and Louise Jameson -- 36 years.
Burns and Allen -- 36 years.
Marx Brothers -- 54 years.
Eddy Christiani and Frans Poptie -- 64 years.
- Modeling a Perfect Pool Break
- Modeling a perfect break in the game of pool with Mathematica.
- Frank Longo Themeless Crossword
- This crossword fill for Fireball by Frank Longa is quite amazing.
- Golly on Android
- The excellent cellular automata program Golly is now available as Golly on Android.
- Wordplay Blog
- The Wordplay Blog at the New York Times has many nice problems, such as the Princess problem.
- Temari Spheres
- A 92-Year-Old grandmother creates a spectacular collection of embroidered Temari Spheres.
- New Folding Record
- MIT's Infinite Corridor was used to make a new folding record, breaking Britney Gallivan's paper folding record. I got her mentioned in the Numb3rs episode Identity Crisis.
- No Four in a Plane
- There are 38 ways to pick 13 points from a 5x5x5 grid so that no four points are in a plane. There is a unique solution for 8 points from 3x3x3, and 232 solutions for 10 points from 4x4x4. What are solutions for 6x6x6 and up?
- Payback Percentages
- Payback percentages are the amount a slot machine must return, and they are defined by law. According to a site explaining how to win at slot machines, the state with the lowest minimum payback is Nevada with 75%, and the state with the highest is Maine with 89%. I never would have guessed that. Much of optimizing life as a gambler now involves researching the law. For example, for poker, the site legaluspokersites.com covers New Jersey Law as it relates to poker.
Martin Gardner celebrates math puzzles and Mathematical Recreations. This site aims to do the same. If you've made a good, new math puzzle, send it to firstname.lastname@example.org. My mail address is Ed Pegg Jr, 1607 Park Haven, Champaign, IL 61820. You can join my moderated recreational mathematics email list at http://groups.yahoo.com/group/mathpuzzle/. My facebook page is at Ed Pegg Jr.