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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

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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).

Rattlesnake Eggs

Get a set here! 
From Amazon: BUY NOW Buzzing Magnet Set 

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Rattlesnake Eggs: polished barium-strontium ferrite ceramic magnets influence each other when many centimeters apart, demonstrating the well known but mysterious action at distance via magnetic fields. Sometimes sold as “buzzers” these magnets come together with multiple bounces creating a characteristic zipper sound. Many shops and online vendors incorrectly label these as hematite- a completely different substance that does not magnetize well.

Bouillant de Franklin (Hand Boiler)

A variety of shapes and colors are available 
From Educational Innovations: BUY NOW: Hand Boilers 
From Amazon: BUY NOW: Hand Boilers 

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Bouillant de Franklin (Hand Boiler): reversible liquid-gas phase transition device made famous by Benjamin Franklin who was one of the first to describe the physics of its operation. The boiling point of dichloromethane is slightly below body temperature - heat from a hand increases pressure in the bottom bulb pushing the green (dyed) liquid through the glass pipe to the top. A vintage handmade version from France.

Luna Kinetic Illusion

Available in a number of colors and configurations:

From KickStarter: Pledge NOW: Luna Kinetic by Mezmoglobe

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Luna Kinetic Illusion: precision machined and crafted kinetic desk toy with helical motion illusion. A metal sphere seemingly defies gravity as a coil spins around it in this astonishing design by Kristoph Krisjans and the Mezmoglobe team. 

Dudeney's Dissection 3D Print

Get this set here!

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

Note: this site contains affiliate links for which I may be compensated

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.

Pencil Hyperboloid

Choose your color and get one here: 
From Etsy: BUY NOW 
Hyperboloid Pencil Holder 

don't forget a set of pencils: 
From Amazon: BUY NOW 
Colored Pencil Sets 

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Better yet- get some thermochromic color changing pencils! 
From Educational Innovations: BUY NOW 
Heat-Sensitive Pencils 

Pencil Hyperboloid: a perfect gift for any math teacher- the precisely oriented holes in this base direct 16 pencils to reveal a hyperboloid, the 3D surface traced by revolving a diagonal(skew) line, the outline of which is the conic section of the hyperbola. A doubly ruled surface for any desktop!

LEDs as PV Cells

Need a UV laser pointer? Get 3 lasers (one of each color) for under $10: 
From Amazon: BUY NOW red+green+blue(UV) laser pointers

LEDs are really inexpensive these days- for $10 get this assortment of 350 LEDs to experiiment with:
From Amazon: BUY NOW: LED assortment 

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For well explained details of the physics see this amazing video by Steve Mould

LEDs as PV Cells: the physics of solar cells (photovoltaic cells) is the reverse process of LEDs (light emitting diodes). Shown here is a very simple circuit I soldered together- a blue LED and red LED connected. When a stream of energetic photons (from a 405nm violet laser pointer) is directed onto the blue diode it produces enough current to power and light the red diode! I saw this demo from fellow physicist @richardvandewege and had to reproduce it for my collection- check out his profile for more fantastic physics via creative demonstrations. 

Map of the Universe: 2dFGRS

Get this laser etched scuplture here:

From Etsy: BUY NOW: 2dFGRS Crystal Sculpture

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Map of the Universe: actual astrophysical data with 221,000 laser etched dots, each dot representing a galaxy of stars and revealing the largest scale structures of our universe. This glass cube contains a 3D mapping of galaxies using the data from the 2dF Galaxy Redshift Survey completed in 2003 which revealed the large scale clumping and voids of galaxies, the true structure of our universe out to about 2.5 billion lightyears. The 3.9 meter wide telescope took about 5 years to collect the spectra of each galaxy in two thin slices of the sky, representing about 4% of the total. The Sloan Digital Sky Survey has since expanded on this to about 40% of the sky now mapped to 12 billion lightyears. Hold and explore this mapped chunk of the universe in your own hands! 

South Pointing Chariot

An excellent and affordable 3D printed version available here:
From Etsy: BUY NOW: South Pointing Chariot

Or get the files to print one yourself: From Printables: South Pointing Chariot 

Note: this site contains affiliate links for which I may be compensated

South-Pointing Chariot: no matter the direction carriage moves, or how many times it turns, the arrow remains pointing south (or whatever direction it was placed initially). This amazing mechanism utilizes a differential gear train, the famous device used in cars to allow wheels to rotate at different rates when cornering. Differential gear trains have the following property, the rotation rate of one shaft is equal to the average rotations rates of the other two shafts. Each wheel of this device drives one of two input shafts, with one geared in reverse, so that if the carriage is moving in a straight line the two rates average out to zero, and the output shaft connected to the top arrow stays stationary. If, however, the carriage turns a corner, one wheel then rotates faster, and the average rate then turns the top arrow at exactly the right rate to stay pointing in the same direction. This design is the most likely basis for the ancient (about 200 CE) Chinese South-Pointing Chariot, described in historical manuscripts which describes a statue on the carriage with an arm extended pointing South. This version was designed by software engineer and tinkerer extraordinaire Matt Keveney, and expertly printed by my friend Alex Kling. 


Radiometers available from these sources: 
From Educational Innovations: BUY NOW Radiometer  (with disk shaped vanes)

A wide variety available here, including some nice blown glass displays: 
From Amazon: BUY NOW Radiometers 

Note: this site contains affiliate links for which I may be compensated

Radiometers: three “light mills” from my growing collection of radiometers (now at 23 so far), including a double with two spinning flys in the same partial vacuum volume. Here the initial light is from a LED, and then a halogen incandescent bulb is turned on which activates the motion. This device goes way back, invented in 1873 by the famous chemist Sir William Crookes when he was investigating partial vacuum environments. Light heats up the “vanes” which then heat up the very thin gas left in the partial vacuum within the bulb- the black side of the vane is hotter than the silver side and any gas molecule that comes into contact with it flies off at a faster speed imparting impulse to the rotor.

Chaotic Triple Pendulum

Availalble here (some fun assembly required):
From Grand Illusions Ltd.: BUY NOW: Chaotic Pendulum Kit

See also this very nice, fully assembed, double pendulum: 
From Etsy: BUY NOW Double Chaotic Pendulum 

Note: this site contains affiliate links for which I may be compensated

Chaotic Triple Pendulum: the intricate dance of chaotic motion from an assembly of three physical pendulums, shown here (partly) in 120 fps slow motion, where the energy imparted to the system moves back and forth between the potential energy of gravity to the kinetic energy of motion until eventually damped out via friction. Chaotic motion is characterized by extreme sensitivity to initial starting conditions, tiny differences in how the system is released leads to dramatically different outcomes each time. A second of many configurations possible with this extraordinary design by Kontax Engineering Ltd.

Cone of Apollonius 3D print

Get this inexpensive version here:

From Etsy: BUY NOW: Cone of Apollonius/ Conic Sections

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Cone of Apollonius 3D print: Slicing a cone with a plane will produce the famous curves known as the conic sections. 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. 

UFO Spin Top

Get this fun and well made top here: 
From Amazon: BUY NOW: UFO Spin Top
or collect the whole set: UFO Spin Top Collection

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UFO Spin Top: this whimsical flying saucer shaped top is made of stainless steel and features a ceramic sphere to reduce friction at the contact point, allowing this heavy and well balanced top to spin for more than 5 minutes with a good snap of the fingers (start up and final seconds of wind down shown here). Spin tops- classic physics toys of antiquity! 

Mirror Rattleback Pair

The amazing work of Emmanuel Péluchon can be purchased here:
From BUY NOW: Fine Woodworked Rattleback

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Other rattlebacks variations found here- check them out: physicsfun rattlebacks

Enantiomorphic Rattlebacks: due to mirror reflection construction, one prefers to spin counter clockwise the other prefers clockwise. This behavior is related to an asymmetry in weight along the left/right symmetry axis of these beautifully crafted objects- the dark wood is Apple which has twice the density of the light colored Basswood(Linden). This asymmetry in weight induces an instability, quite like the vibrations that arise from an unbalanced tire, that transfers the rotational energy to the intermediate rocking vibrations. This amazing set was made by Emmanuel Péluchon, fine woodworker and artist. 

Zulu Telephone Wire Bowl

Get similar weavings here:

From Etsy: BUY NOW: Zulu Wire Bowls

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Geometric Weaving: this Zulu telephone wire bowl, made in the traditions of South Africa, features a brilliant spiral pattern. The bright colors come from weaving strands of colored wires- the kind used to connect phones throughout buildings. This particular pattern inspired using a rotating base to display this bowl as kinetic sculpture.

Magnetic Viewing Film: Fridge Magnetic Structure

Get this new and fun technology here:

From Amazon: BUY NOW: Color Magnetic Viewing Film

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Magnetic Poles of Refrigerator Magnets: visualizing the invisible with color gradient magnetic viewing film- the secrets of refrigerator magnets revealed: strips of north and south poles. Compared to the two poles at the end of the horseshoe magnet 🧲 the collection of parallel strips seen in the fridge magnet is a special orientation of the magnetic poles called a Halbach array, which allows for the combination of poles to create a strong magnetic field on one side and a very weak one on the other- refrigerator magnets only stick on one side by design!