Physics & Math Puzzles

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.

Magic Sand Wand Puzzle

This puzzle was purchased in the 1990s, check back in a week or so as I hope to provide a source for these sand wand puzzles. Meanwhile, please see the next links and videos for other amazing physics puzzles you can own. 

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. 

Ice Melt Demo

Get this similar demonstration kit here:
From Educational Innovations: BUY NOW
Ice Blocks Melt Demo

Ice Melt Demonstration: Wood or Aluminum- which will melt the ice fastest and why? Both blocks start at the same temperature (room temp) and have the same shape and volume. Swipe to reveal result shown in real time (not sped up!) Hint: Although both blocks are at the same temperature, the aluminum feels cool to the touch and the wood block feels warm. Those who have taken basic physics should have an advantage on this question- one block is an excellent insulator and the other a conductor.


Tessellating Geckos

These laser cut hardwood geckos are available here: 
From Etsy: BUY NOW Tessellating Geckos 

Tessellating Geckos: MC Escher inspired lizard cutouts interlock precisely to tile a surface with no overlaps or gaps. Laser cut from maple, walnut, and cherry wood by maker/artist Craig Caesar and inspired by MC Escher’s “Study of Regular Division of a Plane with Reptiles” 1939. G4G week: Martin Gardner wrote about the art and math of Escher in 1961- which helped create the popularity that his work has experienced ever since.

Aqua Drop Puzzle

Three models/colors to choose from: 
From Amazon: BUY NOW Aqua Drop Puzzles 

From eBay: BUY NOW: Aqua Drop Puzzle

Aqua Drop Puzzle: a superhydrophobic coating allows this dexterity puzzle to use a drop of water as the "pinball". The white surface is a silica nano-coating that makes water roll off- a condition sometimes referred to as the Lotus effect because leaves of the Lotus plant have this property. 

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 
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. The physicist and mathematician, Sir Roger Penrose, famous 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”, 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.


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”. 

 

Impossible Bolt

Only available from these aritist/craftsmen: 

From Etsy: BUY NOW: Impossible Bolt & Nuts

Impossible Bolt: one nut threads on clockwise as normal- the other threads on counterclockwise on the same bolt! Not impossible- but carefully engineered and machined. Swipe for partial hint on mechanism. This puzzling curiosity was inverted by Scott Eliott and machined in solid brass by puzzle crafters Steve Nicholls and Ali Morris of TwoBrassMonkeys.

Poly Density Puzzle

Get the kit here: 
From Educational Innovations: BUY NOW Polydensity Bottle Kit 

Poly Density Puzzle: my favorite science brain teaser- white beads and blue beads "float" oddly separated beneath the surface of a clear liquid. If the contents are mixed by shaking the container, the white beads gather at the top and the blue sink to bottom! Adding to the mystery; after about 30 seconds the two layers of beads will have slowly moved back to the middle. What is your guess as to the physics behind this behavior?


Impossible Arrow

One of many creative illusions and curiosities of Victoria Skye. See her work here:

Visit Now: Victoria's Illusion Art

Click here for to explore more "impossible objects" 

Impossible Arrow: an arrow made of wood through the center of standard steel hex nut. The arrow was carved and somehow placed through the nut- neither the wood nor the steel nut was cut or glued to produce this object. Not impossible, but creating this does depend on the use of some obscure physical properties of wood (similar to the impossible nail sculpture). 

Impossible Dovetail

Inexpensive versions of this "impossible box" like that in the video avaiable here:

From Amazon: BUY NOW: Impossible Box Puzzle

Impossible Dovetail: this impossible object is pretty common, but it is a classic, and included in my collection. If one assumes a regular dovetail joint then this construction would indeed seem impossible without cutting and gluing, but what one sees from the sides makes for misleading assumptions as this box opens easily. Swipe for reveal once you’ve thought about about possible constructions. 

Impossible Jar with Golf Ball

Get this "impossible" jar and other amazing things from this shop:

From Etsy: BUY NOW: Impossible Jar & Golf Ball

Impossible Jar with Golf Ball: a regular off the shelf golf ball somehow trapped within a standard glass jar. Neither the ball nor the jar were cut or glued in the fabrication process. The puzzle aspect is to consider how this object was produced (again, I have some theories- but I do not know the secrets of this artist). This incredible piece was made by craftsman and artist Nathan Nickerson, and comes with the golf tee display stand (a nice touch!)


Ambiguous Superhero Object 

Available now- 3D printed ambiguous object Illusion:

From Amazon: BUY NOW: Superhero Ambiguous Object Illusion

From eBay: BUY NOW: Superhero Ambiguous Object Illusion

More of this type hereAmbiguous Object Illusions on @physicsfun 

Ambiguous Superhero Object: A very fun fan art 3D print which makes use of the ambiguous object illusion invented by mathematician Kokichi Sugihara- a clever combination of reflection, perspective, and viewing angle. Printed and sold by 3DNY Design. 

Nova Plexus Tensegrity Puzzle

Precisions machined and available in brass or stainless steel:

From Art of Play: BUY NOW: Nova Plexus Puzzle

Nova Plexus Puzzle: 12 identical brass rods can create 4 interlocking triangles in a perfect symmetry- look carefully and you can see that each rod is in an identical configuration with the 5 others that connect with it. Precision machined notches on the ends of the rods allow them to interlock with elastic tension such that vector sum of the 5 forces on each rod is zero- creating this astonishing geometry as the equilibrium state. Unlock the ends of any two rods and the system instantly disassembles (swipe to view process in slow motion). Invented/designed by artist and computer scientist Geoff Wyvill in 1978, this puzzle has just recently been made available for sale with a limited production run.

Impossible Wallet

Available here: 
From Amazon: BUY NOW Magic Wallet 

From eBay: BUY NOW Magic Wallet

Impossible Wallet: this pocketbook has a special double hinge that allows the wallet to be opened from either side, and leads to some rather nonintuitive consequences. Note that once inserted, the bill shows the same face independent of which way the wallet is opened. The construction of this magic (or flip) wallet is similar to the famous Jacob's Ladder toy.


Mirror Vision Puzzle

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

From Amazon: BUY NOW: MIrror Vision Puzzle

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.