G4G14

Big Knot Variation

Oskar van Deventer

Peter Knoppers

Puzzle

Burr puzzle designed by Oskar van Deventer (used with permission). For G4G14, this 14-piece puzzle felt appropriate. Contrary to the name of the puzzle, these exchange puzzles are in fact rather small.

Solution is available on https://buttonius.com/solutions/big-knot-variation/index.html

G14-005

G4G14

How to Put This Design on an Egg

Susan D. Jones

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.

G14-002

G4G14

The Martian Mayor Problem

T. Arthur Terlep

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.

G14-001

G4G14

Modular Space-Filling Tetradecahedra

Glen Whitney

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.

G14-034

The size of the puzzle is about 10cmx10cmx2.5cm, and it is made by MDF.

Goal: Put all bridges on the board. ]]>

G4G14

Build 14 Bridges

Ryuhei Uehara

Tomoko Taniguchi

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.

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.

G14-021

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

Sierpinski Tetrahedron

Hideki Tsuiki

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.

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.

G14-012