All physicsfun toys

Self Propelled Homopolar Motor

Here are disk magnets I used for the "wheels": 
From eBay: BUY NOW Neodymium Disk Magnets 
From eBay: BUY NOW Neodymium Disk Magnet 

Wire that looks and works well is just 10 gauge ground wire. Inexpensive and available at any local hardware store-- or order a small quantity here: 
From eBay: BUY NOW 10 gauge Copper Wire 

Wikipedia has some good details on the physics of homopolar motors 

Self Propelled Homopolar Motor: cylindrical neodymium magnets supply the static magnetic field for this motor and become the wheels of a very simple vehicle with an AA battery as the energy source. As soon as both ends of the copper wire make contact, an electric current will flow which in turn induces a magnetic field around the wire. This induced field around the copper wire will then interact with the neodymium magnets on each end causing them to spin- a wonderful example of a motor with minimal components.

Lightning 2000 Plasma Lamp

This vintage device is often available on eBay: 
From eBay: BUY NOW 
Vintage Lightning Lamp 


A similar device is available here: 
From Amazon: BUY NOW 
Blue Lightning Lamp

Lightning 2000 Plasma Lamp: low pressure noble gasses glow due to discharge from high voltage. A small high frequency coil at center creates the high voltage potential between the center electrode dome and the outer glass dome which is coated with a thin transparent film of metal. Current flow through the thin gas produces the glowing zigzagged path like that of lightning but more rounded. Shown here in 480 fps slow motion. 


Spinning Liquid Paperweight

Many versions available here 
From Amazon: BUY NOW Liquid Wave Paperweight Toy 

Spinning Liquid Paperweight: two immiscible liquids (three if you count the air bubble) are sorted under gravity by density with the densest on the bottom and the lightest on top. If the container is rotated the boundary between the layers forms a parabola due to the added influence of centripetal acceleration. As seen here in 240 fps slow motion, symmetric waves travel and reflect along the curved surface for the first few rotations until damped out via viscosity and friction. The plastic fish have a density between that of the two liquids so they stay at the boundary layer. 

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.

3D Pentominoes

The set I used for this video is called Pocket Katamino and is available here
From Amazon: BUY NOW Pentominoes 

3D Pentominoes: the 12 possible arrangements of five identical squares, joined edge to edge, form the set of all pentominoes. Since 12x5=60, the pentominoes can tile a 6 x 10 rectangle with no gaps (2339 ways to do this- yet even finding one solution is a challenge). This set of colorful pentominoes is made so that the height of each piece is the same as the width of the constituent squares, such that 3D constructions can be made. Since 3x4x5=60 one can build a box with these dimensions (amazingly, 3940 ways to do this- but again, finding one is still a fun challenge). 


Equitorial Bulge Demostration 

Wikipedia has the details about the actual shape of the Earth: oblate spheroid planets 

Here is an inexpensive toy that shows similar physics: Rainbow Twirler

Equatorial Bulge Demo: two springy circular rings flatten along their axis of rotation in proportion to the rate of spin in this classic teaching demonstration. This device demonstrates that centripetal accelerations applied to an elastic sphere will cause it to bulge at the equator- becoming an oblate spheroid. Isaac Newton predicted that given the Earth’s rotation, the radius to the equator would be larger than the radius to the North Pole by 1 part in 230. He was correct! (although overestimated slightly- swipe for description) Modern measurements indicate 1 part in 294.7. Question: At what location on Earth could you stand on land and be furtherest from its center? Mt Everest is a good guess, but the correct answer is the top of Mt Chimborazo in Ecuador. (swipe twice for details) Although Everest is higher above sea level, the equatorial bulge puts the top of Chimborazo a 2.2 km further into space from the center of the Earth.


Eclipse Diamagnatic Sculpture

Click here to visit this amazing Etsy shop Element83 
Get a magnetic levitation sculpture here: 
From Etsy: BUY NOW Diamagnetic Levitation Sculptures 

Eclipse diamagnetic levitation sculpture. Cast from diamagnetic Bismuth, a golden spherical neodymium magnet levitates trapped in a tunnel within the metal. Diamagnetic substances only have magnetic fields of their own when placed in an external magnetic field from another source- here the sphere magnet supplies the field. Diamagnetic fields are pretty weak though so a powerful cube neodymium magnet sits above the tunnel and is adjusted to help lift the sphere magnet against gravity. Trapped in equilibrium by these fields, any other magnet brought near will change the balance. 

 

Dymaxion Map

Get one there:

From Art of Play: BUY NOW: Dymaxion Folding Globe

Dymaxion Map: today some math fun with this unique mapping of the Earth where the globe is projected onto an icosahedron and then unfolded onto two dimensions. Invented by the famous architect R. Buckminster Fuller, the Dymaxion projection map is designed such that it does not have a “right way up” and showing the continents as “one island Earth”. This mapping also produces less distortion of relative areas and shapes- note here that Greenland looks, correctly, much smaller than Africa- unlike what is seen on many world maps where they look the same size. This version, designed by Brendan Ravenhill, uses flat magnets to allow a very satisfying transformation between the flat 2D net and the 3D icosahedron “globe”.

Single Tube Nixie Clock

This single tube version is an affordable alternative to showcase the vintage aesthetic of the Nixie neon glow:
From eBay: BUY NOW: Single Tube Nixie Clock Base (buy the tube in the next link)
From eBay: BUY NOW: IN14 Nixie Tube

Get the diffraction grating here:
From Amazon: BUY NOW: Diffraction Grating 

Get a beautifully made full four digit clock here:
From Etsy: BUY NOW: Nixie Tube Clocks 

Single Tube Nixie Clock: This minimalist clock uses a standard 5V USB connection and modern electronics to power a single Russian made ИH-14A Nixie tube- here the display shows the time 12:36 flashed in sequence. Long before there were 7 segment LED displays there was the Nixie- cold cathode tubes with a wire mesh and 10 cathodes shaped in the form of numerals 0-9 that illuminate through neon glow discharge at 170Volts. A diffraction grating reveals the brightest emission lines of the neon spectrum including: violet, green, bright yellow, and a bunch of orange/red lines characteristic of this noble has. The “Numeric Indicator eXperimental 1” or NIX 1 was introduced in 1955 by Burroughs Corporation and manufactured until the 1990s.


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. 

The FluoroSphere

The kit includes the UV LED base, elegant glass sphere, and enough fluorescent gel for many repeat lights shows. 

From PyroFarms: BUY NOW: FluoroSphere

From Amazon: BUY NOW: FluoroSphere

The FluoroSphere: intricate and dynamic lights shows are produced within an elegant glass sphere as fluorescent dyes in mineral oil slowly mix into room temperature water. Ultraviolet LEDs (in the base on which the sphere rests) make the dyes glow brightly and reveal the initial nondiffusive mixing structure which includes the phenomena of drops, plumes, and other features of Rayleigh-Taylor instabilities. Shown here, slightly sped up, is the first 8 minutes or so of the process which takes up to half an hour to mix evenly. The green light is characteristic of the famous fluorescein dye.

 

Ernest Borel Watch

These vintage watches are not too hard to find: 

From Etsy: BUY NOW: Borel Cocktail Watches

From eBay: BUY NOW: Borel Cocktail Watches

Moire Kinetic Watch: this beautiful timepiece is an Ernest Borel Cocktail pendant watch made in 1958 featuring the trademark rotating disk (instead of a second hand) which creates a kinetic radiant Moiré pattern. This vintage 17 jewel Swiss watch is old school- powered by a spring that must be wound once a day (elastic potential energy to kinetic). 


Soma and Rhoma Puzzles

The Rhoma Cube is a vintage item and can sometimes be found on eBay:

From eBay: Search NOW: Rhoma and Soma Puzzles

Soma Cubes are available in a wide viariety: 

From Amazon: BUY NOW: Soma Cube

From Etsy: BUY NOW: Soma Cube

SOMA and RHOMA Puzzles: Replace every cube in the Soma puzzle with a rhombohedron to create the Rhoma puzzle- where the seven slanted pieces now make a larger rhombohedron. Here I’ve painted the corresponding Soma and Rhoma pieces to match on these sister puzzles that share identical edge lengths. While there are 240 ways to make the larger cube from the 7 Soma pieces, there is only one solution for the 7 Rhoma pieces. The original Soma Cube is a math toy has an interesting connection to physics- invented by Danish scientist and artist Piet Hein who claimed that this puzzle idea came to him as he was listening to a lecture on Quantum Mechanics by Werner Heisenberg in 1933. The seven pieces are all the ways 3 or 4 cubes can be joined, such that each piece has at least one inside corner.

Peridotite Xenoliths

samples available here: 
From eBay: BUY NOW Mantle Xenolith Peridotite sample

Peridotite Xenoliths: here before you are chunks of Earth's mantle material from 50 kilometers or deeper below the surface, far below the deepest hole ever drilled at 12.3 km (a great effort which didn't even break through to the mantle). However, green peridotite crystals of olivine and pyroxenes are sometimes brought to the surface by viscous lava in the form of xenoliths- inclusions in the volcanic basalt as seen in this sample. This piece was collected from Peridot Mesa in the San Carlos Volcanic Field of AZ. Amazing sample of the inaccessible Earth's interior.

Scale Model of Pluto–Charon Binary System

Get a beautifully detailed Pluto + Charon here: 
From Shapeways: BUY NOW Pluto Charon Set 

Scale Model of Pluto–Charon Binary System: shown here with each in orbit around their common center of mass. The orbit distance of Pluto’s primary moon Charon is only 8.2 Pluto diameters away (very close!), and because Charon is 1/2 the size (and 1/8 the mass) of its parent planet, their common center of mass is far outside Pluto’s surface. (For comparison our Moon is 30 Earth diameters away.) This model also correctly shows how both Pluto and Charon are in tidal lock with each other- one side of Pluto always faces one side of Charon, so the orbit period of Charon is equal to one Pluto rotation (6.4 Earth days). I constructed this model using a 3D printed Pluto and Charon set made by George Ioannidis (based on image data from the New Horizons spacecraft) Scale: Earth diameter = 12 inches.