Physics & Math Puzzles

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!

Impossible Nail

Nice versions are curretnly available from Etsy:

From Etsy: BUY NOW: Impossible Nail

Impossible Nail: An eighteen-penny nail driven through the inner notches of a solid piece of wood. The wood was notched and the nail added- no glue used or cuts made, and the nail is solid and in one piece. Not impossible, but creating this does depend on the use of some amazing physical properties of wood. I won’t reveal the method here but a quick search on YouTube produces a few how-to videos showing the process. 

Bubble Trouble Puzzle

This hard to find puzzle is sometimes found here: 
From magicorum.com: Bubble Puzzle

See more physics puzzles: featured physics 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? Swipe to reveal solution.


Elastic Equilibrium Puzzle

Get this puzzle here:

From Amazon: BUY NOW: Atomic Cherry Puzzle

Elastic Equilibrium Puzzle: six spheres held together by three plastic springs. When assembled each sphere exerts the same force on its four neighboring spheres, producing this equilibrium state only if all six spheres are used to balance all the forces. A fun configuration to analyze in a 1st year physics course- the Atomic Cherry by Brainwright puzzles. 

Reverse Cartesian Diver

Glass divers available here: 
From Amazon: BUY NOW Glass Divers 

The reverse diver needs a bottle with a oval shaped cross section. I used the bottle from this product- it has the right shape and size and the label comes off easily: 
 
From Amazon: BUY NOW Oval Shaped Bottle Source 

Inexpensive and fun diver kits available here: 
From Educational Innovations: BUY NOW Cartesian Diver Kits 

Wikipedia has the details on the Cartesian diver (and reverse diver). 

Reverse Cartesian Diver: physics puzzle (swipe for hint). On the left is a Cartesian diver- pressing on the bottle forces water into the glass diver, which then compresses the bubble in diver’s head allowing it to sink. On the right is a reverse Cartesian diver- again the bottle is pinched but this time the diver ascends- why? 

Bisected Tetrahedron

Available here:

From eBay: BUY NOW: Bisected Tetrahedron

Print your own with these files: Five Screw Puzzles

See the related Tirsected Cube Puzzle

Bisected Tetrahedron Puzzle: two identically shaped pieces interlock to form the famous four faced platonic solid in this ingenious dissection puzzle. The tetrahedron is sliced following a helical path along the 2-fold symmetry axis (middle of one edge to its opposite), creating a smooth disassembly, and a smooth but mildly challenging reassembly. Fun math today from puzzle maker, artist, and mathematician George Hart. 

 


Ice Melt Demo

Get this similar demonstration kit here:
From Amazon: 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.

Perspective Puzzle 2

Vintage puzzles in this series are sometimes available on eBay: 
From eBay: Search NOW Virtual Illusion 3D Puzzle

Perspective Puzzle: twelve 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. 


RPSLK Dice

These dice are available here:

From Amazon: BUY NOW: Rock Paper Scissors Lizard Spock Dice

RPSLK Dice: the famous Lizard Spock extension to the Rock, Paper, Scissors game expressed on 10 sided dice allowing the study of the non-associative nature of the game (Rock wins Scissors, and Scissors wins Paper, but Rock does not win Paper, etc.), and other interesting math. The original RPS game had three “weapons” and only three rules are needed to play the game. Adding Lizard-Spock makes for 5 gestures, but now 10 rules must be used, including “Spock vaporizes Rock”, “Lizard poisons Spock”, and my favorite “Paper disproves Spock” (swipe to see famous graphic). Interestingly, mathematical analysis shows a similar four weapon game with equal odds of winning is not possible. It was also found that the next possible game with 7 gestures would require 21 rules to play. The Lizard-Spock extension was invented by Sam Kass and Karen Bryla in 2005 and made famous on the sitcom Big Bang Theory. 

Doubly Impossible Bottle

Each constructed by hand, each a work of art-  get a personalized bottle here:

From The Bottleologist website: BUY NOW: Impossible Bottle with Frame

From his Etsy store: BUY NOW: Impossible Bottles

Doubly Impossible Bottle: the newest seemingly impossible object in my collection from craftsman/artist Grant Wicks @thebottleologist. An “impossible nail” object was somehow assembled within a Fannys Bay Whisky bottle- and personalized with my logo too! The puzzle aspect is to consider how the bottle was produced (I personally have some theories- but I do not know the secrets of this artist). I can tell you with high certainty that the bottle was never cut or altered in anyway, and it was not somehow formed around the objects inside. 


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 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 is 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).

Impossible Threads

Available here:

From Crux: BUY NOW: Impossible Threads 

Impossible Threads: a classic project for learning machinist skills on a metal lathe where threads are made in the middle of a rod with solid ends- how then where the nuts placed on the threads? The ends are indeed the same piece of metal and where never detached. Swipe to reveal the method that takes advantage of how precisely metal can be machined. 


Wooden Trapped Sphere in Cube

(out of production)

Trapped Sphere in Cube: a surprising aspect of the geometry of spheres and cubes- carved from a single block of wood is a sphere trapped within a cube frame. A classic folk woodworking novelty reconceived here with precision machining to create this seemingly impossible object. 

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.