Educational Innovations

Stainless Steel Rattleback

This metal version is available here: 
From KJ Beckett: Metal Rattleback 

These acrylic versions work great and are inexpensive: 
From Educational Innovations: BUY NOW Rattlebacks 
From Amazon: BUY NOW Rattlebacks 

Stainless Steel Rattleback: prefers to spin counter clockwise. If spun clockwise, a complicated combination of friction, precession, and instability induced vibrations transforms the rotational energy into into rattling (energy of oscillations) and then into rotational energy in the opposite direction! This behavior is related to the asymmetric shape of the bottom of this kind of rattleback, it's somewhat propeller shaped with an "S" curve along the bottom ridge.

The PhiTOP

Get one here! 
From Educational Innovations: BUY NOW PhiTOP 
From Amazon: BUY NOW PhiTOP

The PhiTOP: spinning things often have surprising physics! This unique top is made of solid aluminum in the shape of a prolate elIipsoid- and the name of the top is derived from the following design requirement: the ratio of the semi minor (short) axis to the semi major (long) axis is made equal to the mathematical constant the golden ratio φ (phi). Invented by astrophysicist Kenneth Brecher, this top stands up vertically (when spun with sufficient rotational velocity) due to physics similar to that of the tippy-top. 

US Patriotic Radiometer

Radiometers are available from these sources: 
From Educational Innovations: BUY NOW Radiometer 

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

Hundreds of options on eBay: 
From eBay: BUY NOW Radiometers 

US Patriotic Radiometer: 4th of July physics toy on this 242th year since the the Declaration of Independence. Produced in the 1970s by Kyp-go (maker of Balafire bulbs) the images spin with kinetic energy converted from light. Light heats up the "vanes" which then heat up the very thin gas left in the bulb- the black side of the vane is hotter and any gas molecules that come into contact with it fly off at a faster speed imparting impulse to the rotor. Radiometers with special vanes like this are no longer in production but sometimes pop up for sale online as antiques.


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!

Magnetic Poles of Refrigerator Magnets

Get some magnetic viewing film here: 
From Educational Innovations: BUY NOW Magnetic Viewing Film 

From Amazon: BUY NOW Magnetic Viewing Film 

Magnetic Poles of Refrigerator Magnets: visualizing the invisible with Magnaview film- the secrets of refrigerator magnets revealed. A special orientation of the magnetic poles called a Halbach array allows for a strong magnetic field on one side and a very weak one on the other- refrigerator magnets only stick on one side by design!

Balance Pteranodon

Get this fun and unique balance toy here: 
From Amazon: BUY NOW Balancing Pteranodon 

Get the classic balancing bird here: 
From Educational Innovations: BUY NOW : Balancing Bird 

Balance Pteranodon: weights in the forward wing tips create a center of mass below this pterosaur's beak- making a system that can rotate and oscillate about a stable equilibrium condition. No magnets used or needed for this physics! Usually this toy is found in the form of a bird (direct dinosaur descendent). Pterosaurs are not dinosaurs, but are the largest animals to ever fly, and powered flight has only evolved four times: bats, birds, pterosaurs, and insects- in reverse order. 


Tiny Tippe Top

Available from this shop in Germany: 
From experimentis-shop.de: BUY NOW Tiny Tippie-Top 

Educational Innovations has reasonably priced, regular sized, wood tippe-tops in their shop: 
From Educational Innovations: BUY NOW Tippe-Tops 

From Amazon: BUY NOW Tippe-Tops 

Tiny Tippe-Top: spinning things often have surprising physics! The smallest functioning version of the famous flip-over top I've ever seen. Friction with the mirror provides a torque that acts on the existing angular momentum of the top to flip it over. The top will stay flipped until the spin rate slows down enough to where its center of mass pulls it back to the resting position. 

Diamagnetic Trap Sculpture

This particular sculpture is no longer available, however, Educational Innovations has this nice and affordable starter kit: 
From Educational Innovations: BUY NOW Diamagnetic Levitation Kit 

Dramatic diamagnetic levitation kits are available here: the racetrack magnets are a bit pricey though! 
From eBay: BUY NOW Diamagnetic Levitation Kit 

Diamagnetic Trap Sculpture: a thin disk of pyrolytic graphite hovers and spins in stable equilibrium over a bullseye configuration of magnetic poles. Diamagnetic substances become temporary magnets while immersed in an external magnetic field, and the created diamagnetic field always opposes the external field (in contrast to ferromagnetic substances like iron which attract). Graphite of this type is one of the strongest diamagnets known, and will levitate over a powerful array of neodymium magnets. ‚ú®With sincere appreciation to Tim Rowett for this kind gift. 

Plasma Globe

Plasma globes are now available in many sizes and levels of quality. Here is a source for reasonably priced quality globes: 
From Educational Innovations: BUY NOW Plasma Globe 

From Amazon: BUY NOW Plasma Globes 

Plasma Globe: low pressure noble gasses exhibit glow discharge from high voltage, creating plasma filaments that rise upward due to heating- shown here in slow motion. A small high frequency coil at center creates the high voltage potential between the center electrode and the metal coated glass globe. Current flow through the thin gas produces the colorful emission spectra from the gasses


Hand Boiler

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

From Amazon: BUY NOW 
Hand Boilers 

Hand Boiler: liquid-gas phase transition. The boiling point of dichloromethane is slightly below body temperature - heat from a hand increases pressure in the bottom bulb pushing the purple (dyed) liquid through the glass pipe to the top.

Ooze Tube

Many colors (and two sizes) to choose from: 
From Educational Innovations: BUY NOW 
Ooze Tube 

From Amazon: BUY NOW 
Ooze Tube 


The physics of the liquid rope-coil effect is pretty complex. Here is a recent scientific paper on the topic with nice illustrations. 
Journal of Fluid Mechanics: Multiple coexisting states of liquid rope coiling 

Ooze Tube: viscous polyisobutene fluid timer toy. Some interesting physics phenomena are found in this kinetic art novelty item: the "liquid rope-coil effect" where the fluid thread coils and stacks as it lands on the pooling surface, and a curious periodicity in the rate of flow that is related to the formation of non-spherical bubbles as the air and fluid trade places (shown in time-lapse). The physics of the coiling effect is complex (see the link in my blog). Broadly speaking the coiling is due to the bottom of the fluid rope widening at the contact point with the surface, and as it widens the fluid slows down but not evenly. This uneven rate of flow produces a bend and the elasticity of the stream constrains the rope to a limited radius- hence a stack of coils.

How a Slinky Falls

Get the classic here: 
From Amazon: BUY NOW Mini Slinky 

Get a giant version of the slinky here! 
From Educational Innovations: BUY NOW Giant Slinky: Super Wave Spring 

How a Slinky Falls: amazing physics demonstration with this classic toy. The center of mass of the slinky spring falls with an acceleration of g- note in this slow motion video that the bottom of the slinky does not move until the spring is fully collapsed. Hooke's law plus gravity! 


Radiometer in Arylic

Similar vintage items can often be found on eBay (a bit pricey though): 
From eBay: BUY NOW Radiometer in Acrylic 

Regular radiometers are available from these sources: 
From Educational Innovations: BUY NOW Radiometer 

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

Hundreds of options on eBay: 
From eBay: BUY NOW Radiometers

Radiometer in Arylic: kinetic energy from light in this Eames era vintage Lucite block sculpture with encased radiometer. Light heats up the "vanes" which then heat up the very thin gas left in the bulb- the black side of the vane is hotter than the colored side and any gas molecule that comes into contact with it flies off at a faster speed imparting impulse to the rotor.

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.

Spring/Latch Polymagnets

Avilable here: 
From Polymagnet.com: BUY NOW 
Spring/Latch Pair Demo 


Get some magnetic viewing film here: 
From Educational Innovations: BUY NOW 
Magnetic Viewing Film 

From Amazon: BUY NOW 
Magnetic Viewing Film 

Spring Latch Polymagnets: this pair of coded magnets attract but don’t touch in a state of stable equilibrium at a distance of 1/2 cm- but if one magnet is turned a half twist they latch together. Magnetic viewing film reveals the specific and complex arrangement of N and S poles that allow for this set to act like a spring or a latch (although only if constrained to an axis along their centers). 


Magnetic Sandglass

Get one here: 
From Educational Innovations: BUY NOW Magnetic Sand Timer 

Magnetic Sandglass: ferromagnetic sand collects above a neodymium magnet in the wood base. Each particulate of ferromagnetic iron becomes a temporary dipole magnet in the presence of the magnetic field in the base. The tiny dipoles link up north ends to south ends as they attempt to align with the magnetic field lines. These stacks topple over due to gravity creating interesting patterns.

Magic Sun Stone

Get a magic sun stone (rough gem quality iolite) here: 
From Amazon: BUY NOW Iolite Sample 

Affordable polarization filters and other polarization physics available here: 
From Educational Innovations: BUY NOW Polarizing Film Kit 

The kit also includes a birefringent crystal, colorful optically active mica sheets, and a polarimetry demo that reveals when structures are under stress. A great value for so much physics fun! 
Get the nice display stand here: 
From eBay: BUY NOW Caliper Display Stand 

Magic Sun Stone: gem quality iolite shows very strong pleochroism- its color depends on the polarization of light as it is transmitted through the crystal. The color of this rough iolite gemstone changes dramatically from clear to opaque purple as the orientation of a linear polarizing filter is rotated through 90 degrees. Also known as a "Viking sky compass" since it can detect the polarization of sunlight in the sky and thereby locate the sun for navigation even on cloudy days or when the sun is below the horizon- useful for this time of year far north. 

Polarization Test Card

These inexpensive test cards are available here: 
From eBay: BUY NOW 
Polarization Test Cards 


Get some polarizing filter sheets here: 
From Amazon: BUY NOW Polarizing Sheets 

Explore many aspects of polarization with this kit: 
From Educational Innovations: BUY NOW Polarizing Filter Demo Kit 

See this short introduction to linear polarizing filters on Hyperphysics, and many more details on polarization from Wikipedia

Polarization Test Card: light has features that are invisible to the human eye, such as the orientation of its electric field (denoted as polarization), but can be revealed to us by a polarizing filter, used to block light with specific polarization orientations. Inexpensive test cards like this are often found in shops selling polarized sunglasses. The molecular structure of plastics can rotate the polarization of any light that passes through, and this card has such thin layers added to the top of the photo to create the hidden silhouettes seen here.