Surprise! Puzzles
Puzzle, Word Play
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.
G4G13
Dick Hess
G13-079
4 x 13
Game
Art
Recreational Math
There are 52 cards in a standard deck of playing cards: four suits of 13 cards each. To design a deck of cards, one needs to establish the four suits, each with its own symbol and/or concept, and find a logic for generating the 13 cards in each suit, usually related to the numbers from 1 to 13. My exchange gift is a booklet summarizing my progress to date in designing a set of playing cards based on ideas that Martin Gardner wrote about in his books and columns. The talk corresponding to this item can be found here: <span><a class="in-cell-link" href="https://www.youtube.com/watch?v=ZijlID83FTg&t=15s" target="_blank" rel="noreferrer noopener">https://www.youtube.com/watch?v=ZijlID83FTg&t=15s</a></span>
G4G13
Margaret Kepner
G13-020
Rubik's Crew - Pinkie Pie
Puzzle
My Little Pony, 2x2, Rubiks Cube
G4G13
Tanya Thompson
G13-069
Lights & Spheres
Art
Toy
Science
A 7cm green plastic sphere with a surface of conical projections, otherwise known as a Cando Massage Ball.
Titanium LED keychain flashlights: I will ship 200 with white LED, 100 with red, blue and green LEDs. Each attendee will receive one light with white LED, and one light with either blue, red or green LED.
G4G13
Stephen Turner
G13-050
Cavalieri Content Cups
Art
Recreational Math
Just as 13 breaks up nicely as the sum of 8 and 5, so too does the (volume of a) cylinder break up nicely as the sum of a cone and hemisphere, a fact we have seen demonstrated at previous Gatherings in vivid ways. But the one-diagram proof of this partition using Cavalieri's principle is remarkably flexible, as the non-standard Cavalieri Content Cups to be distributed will show. For more information, see v.gd/stinf.
G4G13
Glen Whitney
G13-048
Pattern Stacker
Puzzle
Art
An abstract spatial thinking pattern puzzle
G4G13
Alison Yada
G13-064
Sierpinski Tetrahedron
Art
Recreational Math
A 3D-printed copy of the 5th-level (i.e., 1024 tetrahedrons) approximation of the Sierpinski Tetrahedron.
Please enjoy the beautiful shadows under sunshine.
In particular, this object has projections with positive measure and the shadow contains an openset from some directions.
Such direction is characterized as follows.
Let A, B, C, D be the images of the four vertices and let x and y be AB = x AC + y AD.
The shadow has a positive Lebesgue measure if and only if x and y are rationals of the form p/q for odd numbers p and q.
G4G14
Hideki Tsuiki
G14-012
Build 14 Bridges
Puzzle
Game
Recreational Math
The puzzle is strongly related to the number 14.
The trick is based on a pythagorean triple.
The size of the puzzle is about 10cmx10cmx2.5cm, and it is made by MDF.
Goal: Put all bridges on the board.
G4G14
Ryuhei Uehara
Tomoko Taniguchi
G14-021
Modular Space-Filling Tetradecahedra
Puzzle
Art
Recreational Math
This Gift Exchange item will consist of four flat pre-cut polyethylene sheets that can be assembled to produce two truncated octahedra with connectors for interlocking into the space-filling arrangement of copies of this polyhedron. Multiple participants can combine their items to produce large three-dimensional structures.
G4G14
Glen Whitney
G14-034
The Martian Mayor Problem
Recreational Math
The Martian Mayor Problem looks at designing square modular networks which create Euclidean distances between modules. The catch is that there are a limited number of tunnels (connections) between modules. This is a mostly open problem as far as I know.
G4G14
T. Arthur Terlep
G14-001
How to Put This Design on an Egg
Art
Recreational Math
I have made a full-color, two-sided instruction sheet on how to draw the attached design on an egg, along with a laminated picture of one of my eggs that has adhesive on the back to become a sticker.
G4G14
Susan D. Jones
G14-002
Losing Friends with Non-transitive Pip Dice
Game
Legacy
A pair of standard, pipped, six-sided dice has had its pips painted in three colors. When you roll one of them and count pips of two of the colors, on average, white beats red, red beats blue, and blue beats white. However, when you roll both dice together, red beats white, white beats blue, and blue beats red.
G4G14
Alexandre Muniz
G14-006
Custom Zometool Struts
Puzzle
3D printed custom Zometool struts, and a Zometool ball.
G4G14
Aaron Siegel
Scott Vorthmann
G14-007
Entropy
Puzzle
Sudoku with some added rules. This puzzle can only be solved in conjunction with the gift "Palindromes" by Elizabeth Gallagher.
G4G14
Neil Calkin
G14-009
Shibori Dyed Hankerchiefs
Art
In anticipation of G4G14, I undertook the mathematical art project of using itajime shibori to dye hundreds of handkerchiefs so that each participant could receive a unique such handkerchief in his or her gift bag. The handkerchiefs represent six of the seven types of wallpaper patterns achievable with itajime shibori.
G4G14
Carolyn Yackel
Bobby Stecher
G14-011
Cube-it Puzzle
Puzzle
9 loose square wafers of plastic with a hole in the center of all but one that has a cylindrical pin. It is clear that the wafers can be stacked on the pin. 7 of the wafers have notches of various size in the edges. There are no hints included. Each wafer can be flipped or rotated in 4 positions in relations to each other and can be in one of 8 positions on the stack. The goal is to find out what it is.. and I'm not telling! The puzzle is 3d printed in white PLA, using two Creality CR10S printers. It was designed using Rhino and sliced using Simplify3D.
G4G14
Craig Newswanger
G14-013
A G4G14 Puzzle
Puzzle
Recreational Math
This is a paper ring with a number puzzle. The hint is actually the logo that is at the beginning (which of course will be right after the end when it's a ring).
G4G14
Skona Brittain
G14-014
Zebra Stripe Card
Recreational Math
Zebra stripe IBM binary card.
G4G14
John E. Miller
G14-015
Peace Angel Maze Card
Game
Full color original art maze card of an Angel seeking peace.
G4G14
Elizabeth Carpenter
G14-018
Hand of Art Stickers
Art
Two removeable vinyl stickers of the artist's hand.
G4G14
Mindy Korth
G14-019
Troxes
Puzzle
Like Origami meets Lego. No scissors, tape, or glue. This modular paper cutout is based on triangular geometry and mates with neighbors (edge-connecting) to create tetrahedra, octohedra, and icosahedra. The resulting polyhedra can then mate once again in their volumetric form by face-connecting with other polyhedra.
Troxes were inspired by Jef Raskin's Bloxes, a cardboard architecture exploration. Troxes in contrast are hand-held, created from a beautiful single ply paper called Plike, and promote non-rectilinear spatial exploration and awareness.
Troxes have won numerous awards at Maker Faires and been featured at the MIT Museum, New Museum and MoMath in NYC amongst other top art and design institutions.
G4G14
Jonathan Bobrow
G14-020
Polarizing Puzzle
Puzzle
Two rectangular sheets that filter light according to polarization- with a twist. Rotating the two sheets ninety degrees with respect to each other results in all light blocked as expected, but flipping over a sheet also gives a similar result. Does this imply new physics? Reconciling this unexpected behavior is the problem left to the reader.
G4G14
Raymond Hall
G14-022
Akio's Dahlia Star Translucent
Art
I invented the Fibonacci Turbine in an origami way. The wing itself functions as a rotating shaft. The structure is so simple that it is robust. It can be used for many engineering applications.
G4G14
Akio Hizume
G14-023
Palindromes
Puzzle
Sudoku with some added rules. This puzzle can only be solved in conjunction with the gift "Entropy" by Neil Calkin.
G4G14
Eliza Gallagher
G14-024
Magic Pizza Guy
Magic
Puzzle
Solve these puzzles and get a pass to the Magic Castle.
G4G14
Nathaniel Segal
G14-026