All physicsfun toys

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.

Kostick Stars

Two versions available here: 
From Art of Play: BUY NOW 
Kostick's Stars 


Here is the detail of the connections of the 6 star from the patent document: 
 
Learn more about John Kostick here: John and Jane Kostick handcrafted mathematical constructions

Kostick Stars: The geometric forms of these kinetic sculptures snap into place due only to the balanced tension forces between thear slightly bent bronze wires. The large star is comprised of six struts, each made of 5 wires, which are made to intersect and weave though each other with beautiful geometric regularity. Similarly the small star has 4 struts each made of 3 wires. The ends of the 6 struts of the large star become the 12 vertices of an icosahedron, and the ends of the 4 struts of the small star point to the 8 corners of a cube. Both stars can be collapsed along many of the symmetry axes. Invented and patented in 1970, these stars are still produced and sold by artist and designer John Kostick. 

Salt Fractionation

All the ingredients are available from your local market/drugstore. The trick is to find a dye that works for acetone, but will not color water- believe it on not blue glitter will color the acetone nicely and not change the salt water. Follow this link for details: 
ChemEd X: Blog of Prof. Tom Kuntzleman 

Of course Amazon has what you will need:

From Amazon: BUY NOW 
acetoneblue glitterfood coloring, cool bottle 

Salt Fractionation: two liquids that won’t stay mixed! Acetone (dyed blue) floats on top of the higher density salt water (dyed orange). Acetone usually dissolves in water through hydrogen bonding interactions, but solubility can be altered. In a process called “salting out” a sufficient amount of salt is dissolved such that the water molecules, which are much more attracted to the resulting Na+ and Cl- ions (through ion-dipole bonds), will then ignore the weaker acetone hydrogen bonds. This results in the spontaneous separation (shown here in real time) of the liquids no matter how well shaken up. 


Poly acrylamide Polymer Vanishing Act

Get some of these grow-spheres here: 
From Educational Innovations: BUY NOW Growing Spheres 

Poly-acrylamide Polymer Vanishing Act: these spheres of hydrophilic polymer have an almost identical index of refraction as that of water- thus when submersed they become invisible. Note the elasticity of these spheres from the way they bounce, while at the same time they refract their surroundings as a spherical lens. The super absorbent spheres start as hard crystals with a radius of 2mm and grow to 11mm when immersed in water. So much physics going on here! 

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.

Dudeney's Dissection

Get this version here: 
From Grand Illusions Ltd: Dudeney's Dissection 

A nice wood version is available here: 
From Etsy: BUY NOW Dudeney's Dissection 

See both Wikipedia and Wolfram MathWorld for more details on the history and math of this geometrical oddity. 

Dudeney's Dissection: an equilateral triangle can be cut (dissected) into four pieces that will then assemble into a square. Interestingly the four parts are all different in shape (the green and yellow pieces are similar but not the same). This hinged model is comprised of precision machined and anodized aluminum, and can be folded back and forth between the two simplest regular polygons. It is not known if a similar three piece dissection is possible. Also called the haberdasher's problem and described in 1907 by Henry Dudeney it is the only 4 piece solution known.


Oscilating Cylinder Steam Engine

Get this tiny working engine here: (brass and stainless steel) 

From engineDIY: BUY NOW: Tiny Steam Engine

Two other similar mini-engines to consider: BUY NOW: Mini-Steam 1, Mini-Steam 2 

Oscillating Cylinder Steam Engine: a functional “wobbler” type piston steam engine complete with boiler and flywheel. In this design the cylinder and piston both rock back and forth, acting as the valve mechanism to allow the hot steam to enter through a small hole, and then exit on the next stroke out through the tiny exhaust port in the top. Takes about 4 minutes to get going after the lamp is lit. A tiny version of the invention that powered the industrial revolution.

Curie Point Heat Engine

This DIY project is pretty easy to build. One half of one of these inexpensive magnetic necklace clasps will work well for the heated magnet. 

From Amazon: BUYNOW: magnet for curie point engine

Curie Point Heat Engine: when the magnet on the end of the wire heats up to a particular temperature (the Curie point) its magnetic field is temporarily lost until it cools. This engine design uses a second magnet to pull the swinging magnet back into the heat source once the magnetic field is reestablished. Repetition of this process creates mechanical motion as long as the heat source is fueled.

Vintage Wilesco Steam Engine

Available here: 
From Amazon: BUY NOW Wilesco Model Steam Engines 

Wikipedia has a very nice description of the history and inner workings of steam engines 

Vintage Wilesco Steam Engine: a working model reciprocating piston steam engine complete with boiler, flywheel, governor, and whistle. The invention that powered the industrial revolution on a desktop! My father bought this model D16 in 1970- with just a little cleaning and oiling it fired right up. Wilesco has been producing model steam engines since 1960 and still manufactures and sells the D16.


Tea Candle Steam Engine

Get one from these fine sources: 
From Educational Innovations: BUY NOW Tea Candle Steam Engine 
From Amazon: BUY NOW Tea Candle Steam Engine 

Tea Candle Steam Engine: a functional piston steam engine complete with boiler and flywheel. Takes about 2 minutes to get going after the candle is lit. The invention that powered the industrial revolution on a desktop! Made by Wilesco. 

Tea-Light Floating Engine

Get one from my friends at Grand Illusions! 
From Grand Illusions Ltd.: BUY NOW Floating Steam Engine 

Tea-Light Floating Engine: a candle powered super simple steam engine. The engine is just a coil of copper tubing filled with water. Steam builds up pushing water out with an explosive jet- which then results in a vacuum in the coil which pulls more water in to repeat the process. The water expulsion is in the form of jet directed out the end of the tube whereas the refill comes back in to the tube from a larger range of angles- so on balance the engine moves opposite to the direction of the jets. 

Thermobile: Nitinol Engine

Get one here: 
From eBay: BUY NOW  Nitinol Loop Heat Engine

Thermobile: Nitinol wire loop heat engine- the memory wire straightens out when heated (contact with heat conducting brass wheel) causing the wheels to spin, providing mechanical kinetic energy from a cup of warm tea water. See previous post for a demonstration of Nitinol wire.


Drinking Bird Heat Engine

Get this famous physics toy from these sources: 
From Educational Innovations: BUY NOW 
Drinking Bird Engine 

From Amazon: BUY NOW 
Drinking Bird Engine 


Wikipedia has wonderful details about the rich history (and further descriptions of the operational principals) of the Drinking Bird
Drinking Bird Heat Engine: time lapse of 15 minutes into 15 seconds (4 cycles). Cooling by evaporation at the head leads to lower pressure in the top bulb, the dichloromethane fluid rises up the neck making the bird top heavy and the bird tips over dipping its beak and letting the fluid return to the bottom bulb. The time lapse allows a clearer picture of how the fluid rises, shifting the center of mass, and how tipping makes the glass column lift out of the fluid in the bottom allowing the pressure to equalize and letting gravity pull the fluid to return to the base. Process repeats as long as the top stays wet. So much physics in one hypnotic toy!

Rocking Stork Drinking Bird

This artisitic version of the Drinking Bird available here:
From drinkingbird.eu: BUY NOW: Rocking Stork

Get a standard Drinking Bird from these sources: 
From Educational Innovations: BUY NOW 
Drinking Bird Engine 

From Amazon: BUY NOW 
Drinking Bird Engine 


Wikipedia has wonderful details about the rich history (and further descriptions of the operational principals) of the Drinking Bird
Rocking Stork: this species of drinking bird toy comes from the Czech Republic where each is crafted in blown glass by an artisan. This classic physics toy is a functional heat engine- cooling by evaporation at the head/beak leads to lower pressure in the top bulb, the pressure in the bottom bulb pushes the dichloromethane fluid (here dyed red) up the neck making the bird top heavy and the bird tips over dipping its beak and letting the fluid return to the bottom bulb. The process repeats, and as long as the top bulb stays wet and cooler than the bottom this heat engine will continue to cycle.

Stirling Engine

Get one here: 
From Amazon: BUY NOW Low Temp Stirling Engine 
From eBay: BUY NOW Stirling Engines 

Stirling Engine: low temperature difference engine turns a fraction of the heat of hot tap water into mechanical motion. For this engine the heat source is the hot tap water, and the heat sink is the room temperature air. Really nice model and super inexpensive for a display engine of this type.


Turbine Convection Color Candle

Available here: 
From MOMA: BUY NOW Convection Color Candle 

Turbine Convection Color Candle: a simple heat engine by designer Achille Castiglioni- rotational motion resulting from the convection of hot air due to the candle flame of a tea light. All moving parts of thin stainless steel with semitransparent colored panels. Energy transfer: chemical bonds to heat to kinetic energy of the rising air to rotational kinetic energy of the turbine. 

Dresden Glass Bead Star Tea Light

These gometirc candle holders are available from the artist's store here:

From glasperlenstern.de: BUY NOW: Glass Bead Star Tea Light

Dresden Glass Bead Star: concentric designs of spherical glass beads produce geometric symmetries of shadow and refracted light from a tea light candle which serves as a point source of illumination. This “Glasperlen Stern” candle holder is one of many configurations offered from Dresden artist Andreas Schildhauer, each with glass set into porcelain from Freiberg.