### Shashibo Geometric Art

From Art of Play**: BUY NOW : Shashibo Geometric Art**

Shashibo Geometric Art: dissect a cube into 12 equal irregular tetrahedra, connect these pieces symmetrically with hinges, and add 36 magnets to create a device with more that 70 geometrically interesting and aesthetic configurations.

### Dudeney's Dissection 3D Print

Get this set here!

From Etsy: **BUY NOW: Dudeney's Dissection 3D Print **

Dudeney's Dissection: an equilateral triangle canbe cut (dissected) into four pieces that will then assemble into a square. This 3D printed version comes as a puzzle- fit the pieces in each of two containers- a square and a triangle, which also makes it clear the two supplied shapes are of equal area. Fun fact: It is not known if a similar three piece dissection is possible. Also called Haberdasher's problem and described in 1907 by Henry Dudeney it is the only 4 piece solution known.

### Stomachion Puzzle

Get this 3-color laser cut acrylic version here:

From Kadon Enterprises: **BUY NOW: Stomachion Puzzle**

Also a very nice multicolor acyrlic version here:

From Etsy: **BUY NOW: Stomachion Puzzle**

Learn about the 1998 discovery of the lost writings of Archimedes (and the technology used to recover them) in this TED talk.

Ancient Stomachion Puzzle: the oldest known puzzle, discovered in the writings of the great Greek physicist and mathematician Archimedes from some 2200 years ago. The puzzle is a dissection of a square into 14 polygons, where the areas of each piece are integer multiples of each other (a curious way to slice it up). In 2003 Bill Cutler showed that there are 536 district ways to configure these pieces to make the square (five are shown here), ignoring simple rotations and reflections. Swipe to see the most famous solution, attributed to Archimedes himself, that was found in an ancient manuscript discovered only in 1998- before this date historians knew the name of the puzzle, but no one knew what it looked like. Kate Jones, the maker of this particularly aesthetic version, found that when using only three colors for the polygons, there are only 6 solutions where no two pieces of the same color touch (four solutions shown here).

### Uphill Roller

This set available here:

From Amazon: **BUY NOW: Uphill Roller Double Cone**

Uphill Roller: a double cone (like two funnels connect by their tops) will roll up a set of inclined rails. Although the bi-cone rolls toward the higher end, its center of mass descends due to the geometry of the rails. This curious construction was first published in 1694 by the noted surveyor William Leybourn to promote “recreation of diverse kinds” towards the “sublime sciences”. Physics fun from three centuries ago!

### Mirror Vision Puzzle

More than three versions of this puzzle out there. Get one here:

From eBay: **BUY NOW: Mirror Vision Puzzle**

Mirror Vision Puzzle: this Harry Potter themed puzzle has only 9 pieces but each supplies two parts of the final image- without the mirror one gets only half the picture. The top of each square is a corrugated lenticular composition of two images, and when viewed from the correct angle only one image can be seen directly, with the other reflected in the mirror, which combine in this case to reveal the famous phoenix bird of the HP stories. Flipping over the puzzle squares produces a second image to solve, this time a basilisk. An ingenious puzzle form from inventor/designer Mark Setteducati and sold by Mattel.

### 10 Hex Puzzle

This and other beautiful and well made puzzles are available on Etsy:

From Etsy: **BUY NOW 10 Hex Puzzle **

Two great resources about these polyhexs: polyform puzzler page and puzzleworld page

10 Hex Puzzle: this puzzle is comprised of pieces which are the set of all ways three and four hexagons can be joined with a common edge. There are 3 trihexs and 7 possible tetrahexs, and similar to pentominoes, these 10 polyhexs can assemble into a large hexagon. Amazingly there are exactly 12,290 solutions to this puzzle- but it’s still a challenge to find just one!

### 3D Pentominoes

The set I used for this video is called *Pocket Katamino* and is available here

From Amazon:** BUY NOW Pentominoes **

3D Pentominoes: the 12 possible arrangements of five identical squares, joined edge to edge, form the set of all pentominoes. Since 12x5=60, the pentominoes can tile a 6 x 10 rectangle with no gaps (2339 ways to do this- yet even finding one solution is a challenge). This set of colorful pentominoes is made so that the height of each piece is the same as the width of the constituent squares, such that 3D constructions can be made. Since 3x4x5=60 one can build a box with these dimensions (amazingly, 3940 ways to do this- but again, finding one is still a fun challenge).

### Soma and Rhoma Puzzles

The Rhoma Cube is a vintage item and can sometimes be found on eBay:

From eBay: **Search NOW: Rhoma and Soma Puzzles**

Soma Cubes are available in a wide viariety:

From Amazon: **BUY NOW: Soma Cube**

From Etsy: **BUY NOW: Soma Cube**

SOMA and RHOMA Puzzles: Replace every cube in the Soma puzzle with a rhombohedron to create the Rhoma puzzle- where the seven slanted pieces now make a larger rhombohedron. Here I’ve painted the corresponding Soma and Rhoma pieces to match on these sister puzzles that share identical edge lengths. While there are 240 ways to make the larger cube from the 7 Soma pieces, there is only one solution for the 7 Rhoma pieces. The original Soma Cube is a math toy has an interesting connection to physics- invented by Danish scientist and artist Piet Hein who claimed that this puzzle idea came to him as he was listening to a lecture on Quantum Mechanics by Werner Heisenberg in 1933. The seven pieces are all the ways 3 or 4 cubes can be joined, such that each piece has at least one inside corner.

### Anamorphic Harry Potter Puzzle

No longer in production but available on eBay:

From eBay: **BUY NOW: Harry Potter On Reflection Puzzle**

Mirror Anamorphic Harry Potter: the conical mirror of the silver container reflects and reveals the distorted scenes in this 200 piece jigsaw puzzle of the famous wizard and school. The shape of the mirror allows for a mathematical operation, a type of affine transformation, to map the distorted image of the puzzle to the restored image reflected by the mirror. Real magic!

### Impossible Pipe Elbows

These are very hard to find- I had to make this one. Contact @physicsfun via DM if you really want one.

Many other types of impossible objects are avialable- see these links and videos: **Impossible Objects**

Impossible Pipe Elbows: made from standard pipe fittings held together only by their threads. No glue of any kind was used in its making. Design inspired by puzzle maker and artist Saul Bobroff.

### Magic Sand Wand Puzzle

This puzzle was produced in the 1990s, sometimes found on eBay (currently two avialable):

From eBay: **SEARCH NOW: Magic Sand Wand Puzzle**

Wikipedia has a good introduction to the possible mechanisms of the Brazil nut effect

Magic Sand Wand Puzzle: this week’s physics brain teaser- move the steel ball through the sand to the other end of the tube. Amazingly it can be done in less than 6 seconds! Hint: spinning won’t help this time. The solution to this vintage puzzle relies on some interesting physics concerning granular convection. Answer below and swipe to reveal solution.

### Cylindrical Lens Puzzle

A similar puzzle (but taking advantage of horizontal symmetry) available here:

From Educational Innovations: **BUY NOW Cylindrical Lens Puzzle **

Cylindrical Lens Puzzle: this cylinder of acrylic acts as lens that focuses light along a line rather than a point- and thus it can invert an image along its symmetry axis. Puzzle question: the word "GREEN" is flipped by this lens but the word "TOMATO" seems unaffected. Is the physics significantly different for red wavelengths as compare to green? Or is there another explanation/trick? Answer below.

### Penrose Tiling Puzzle

This puzzle was produced and sold in the 1990s.

The individual tiles can be found on eBay (and sometimes the whole puzzle):

From eBay: **Search NOW Penrose Pentaplex Puzzle **

Wikipedia has the details on Penrose Tilings and their inventor Sir Roger Penrose (Recently won Nobel Prize!)

A nice basic version of Penrose Tilings is available here:

From Etsy:** BUY NOW Penrose Tiles **

Penrose Tiling Puzzle: a challenging puzzle with pieces that come in only two shapes. Sir Roger Penrose- who just yesterday won the Nobel prize in physics for his contributions to General Relativity- also discovered tessellations (tilings) that are aperiodic even though the two tile types are regularly shaped polygons. If one tries to shift a part of a Penrose tiling, the shifted part will not align or match up with any other part of the same tiling- all the way out to infinity! This puzzle, entitled “Perplexing Poultry”, created and sold by Penrose himself, uses polygons modified into crazy looking birds such that the tiles can only connect in specific ways to ensure the non-repetitive nature of the Penrose tiling structure. Shown here is one way these two tile types will fill the plane.

### Trisected Cube

Get this puzzle here:

**BUY NOW: Trisected Cube Puzzle**

This puzzle came in my Curiosity Box subscrition. A great way to start collecting your own physics toys (and other brain food):

From the Vsauce team: **BUY NOW: The Curiosity Box**

Trisected Cube Puzzle: three identical pieces interlock to form a cube in this ingenious dissection puzzle. The cube is sliced following a helical path along a corner to corner diagonal, creating a smooth disassembly, and a smooth but surprisingly challenging initial reassembly. Invented by Robert Reid and designed by puzzle master Oskar van Deventer.

### Perspective Puzzle

Vintage puzzles in this series are sometimes available on eBay:

From eBay: **Search NOW Virtual Illusion 3D Puzzle **

Perspective Puzzle: ten flat images, when ordered and spaced correctly, combine to produce this 3D illusion of structure and depth. This vintage toy by Mattel was sold as “Virtual Illusion 3D Puzzle” where the challenge is to scramble/shuffle the 12 sheets and then place them in the correct orientation and order to complete the image. A fun application of the math and physics of anamorphosis and perspective.

### Jacob’s Ladder Image Flip

Available from this shop in Spain:

From Punto Verna: Reproduction Jacob's Ladder

Classic versions of this toy available here:

Amazon:** BUY NOW Jacob's Ladder Toys **

The same ribbon hinge mechanism is used to make the "magic" wallet click here

Jacob’s Ladder Image Flip: with a twist of the wrist this reproduction flips back and forth between an image of Queen Victoria and that of Prince Albert with a satisfying click-clack sound. The earliest description of the ribbon hinge mechanism that creates this kinetic illusion of cascading blocks comes from a magazine article in Scientific American in 1889.

### Impossible Knot

Follow the link below for full explanation and instructions.

From mathematician/artist George Hart: Tying the Knot Puzzle

Impossible Knot: how did this overhand knot get into this closed continuous band of rubber? It did not get there by cutting the loop, tying a knot, and rejoining it. Amazingly this band was once a rubber o-ring. How was it cut to produce a knot? An “impossible object” related to the Möbius strip by mathematician and artist George Hart- a brain teaser puzzle he calls “Tying the Knot”.

### Star Wars Illusion Cube

These vintage fast food toys can be found on eBay:

From eBay:** BUY NOW Star Wars Illusion Cube **

Star Wars Mirror Illusion: Symmetry + Reflection = Illusion. A two sided mirror and symmetric images combine to make this Taco Bell toy from 1996.