### 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.

### 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”.

### 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.

### Bubble Trouble Puzzle

This hard to find puzzle is sold as a magic trick here:

From magicorum.com: **Bubble Puzzle **

See more physics puzzles: **featured physics based puzzles**

Bubble Trouble Puzzle: physics brain teaser- the trick here is to move all air bubbles to the center bulb. As with all puzzles featured here on @physicsfun, the solution relies on some fun basic physics principles- can you figure out which ones? Answer below and swipe to reveal solution.

### 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.

### Cone of Apollonius

Similar models available here:

From Amazon: **BUY NOW: Cone of Apollonius**

From Etsy: **BUY NOW: Cone of Apollonius**

Cone of Apollonius: Slicing a cone with a plane will produce the famous curves known as the conic sections, as demonstrated with this beautiful vintage wood model by Nasco. Slicing at a right angle to the cone’s axis of symmetry produces a circle, and tilting the intersecting plane a bit produces an ellipse. When the plane is tilted parallel to the side of the cone the curve produced is a parabola, and tilting even further creates a hyperbola. The discovery of the mathematics demonstrated here are attributed to Apollonius of Perga from about 250 BC- thousands of years later Kepler, Newton, and others showed these conic sections to be intricately connected to many branches of physics such as planetary orbits and the optics of telescopes.

### 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.

### 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.

### Hydrophobic Water Maze

Wonderfully well crafted and available from this shop :

From Etsy store TheSmallestWorkshop:

**BUY NOW Hydrophobic Water Maze**

Hydrophobic Water Maze: a superhydrophobic coating allows this dynamic puzzle to use a drop of water as the "pinball", which can split into multiple smaller drops and recombine along the way. The wood surface is treated with 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.

### 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.

### Raketti Puzzle

Versions of this puzzle avaioable fron these sources:

From Etsy: **BUY NOW Raketti Physics Puzzle **

From eBay: **BUY NOW Raketti Physics Brain Teaser **

Raketti Puzzle: physics brain teaser- the challenge is to remove the cone topped cylinder from the hole without touching the bottom container (no fair using sticky tape or such). It can be done in a matter of seconds! The solution to this puzzle (like others featured here) relies on some fun physics principles. Answer below and swipe to reveal solution.

### Coin Escape Puzzle

Available here:

From eBay: **Search NOW: Coin Escape Puzzle **

From Amazon:** BUY NOW: Coin Escape Puzzle**

Another coin escape puzzle (fits US Dollar), the YOT:

From Amazon: **BUY NOW **

Silver Dollar Escape Puzzle

Coin Escape Puzzle: physics brain teaser- remove the coin without breaking the container or using any tools other than your hands. Of course you spin it to get the quarter out- but exactly how? The solution to this puzzle (like others featured here) relies on some fun basic physics of spinning things. Answer below and swipe to reveal solution.

### Magnetic Cube

Many colors to choose from:

From MagneticCube.com: **BUY NOW Magnetic Dice Cube **

See also the original indestructibles post: Magnetic Acrylic Rubik's Cube

Magnetic Cube: a twisty Rubik’s Cube puzzle made from 27 dice and 108 neodymium magnets. This cube includes the scrambled states and solutions of the original 3x3 Rubik’s Cube but is held together only by magnets! The magnets, in this special configuration, lock the dice together with a satisfying click upon rotation. This beautiful cube was produced by Owen Lillywhite of magneticcube.com and is based on a gfixler design posted on instructables.

### 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.

### Ambiguous Superhero Object

### Impossible Caged Golf Ball

Some nice versions of this impossible object available here:

From Etsy: **BUY NOW: Golf Ball in Wood Cage**

See more of these thought puzzles in my collection here: Impossible Objects

Impossible Caged Golf Ball: Here a regular off-the-shelf golf ball somehow trapped within a cage made from a solid piece of hardwood walnut. Neither the ball nor the wood were cut or glued in the fabrication process. The puzzle aspect is to consider how this object was produced (I have some theories- but I do not know the secrets of this artist).

### Penrose Aperiodic Rhombs

This set avaiable here:

From : **Search NOW Penrose P3 Tiling**

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

Another nice version of Penrose Tilings is available here:

From Etsy:** BUY NOW Penrose Tiles **

Penrose Aperiodic Rhombs: a famous aperiodic tiling with just two shapes- a pair of rhombuses with equal sides, but with the ratio of their areas made to equal the golden ratio. Note that although the starting pattern of 10 tiles is symmetrical, adding any further tiles breaks the symmetry, as highlighted by the path of the double curves. Sir Roger Penrose- who just 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! In this construction, single and double line patterns must align 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.

### 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.