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.

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 


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!

Mirascope

Similar devices available here:
From Educational Innovations: BUY NOW Mirascope 
From Amazon: BUY NOW Mirascope 
 

Mirascope: two parabolic mirrors create a 3D image above the actual object. A repost of one of my favorite physics toys ever. The image of the dice made here is not a hologram and is produced solely by reflection of light rays between special concave mirrors. Discovered circa 1969 by Landry and Elings at UC Santa Barbara.


Iron Filings in Silicone Oil Suspension

Available from these fine sources: 

From Amazon: BUY NOW Magnetic Field Viewer Set (get the demo set)

Similar device here:
From Educational Innovations: BUY NOW Magnetic Field Viewer with Magnet 

Iron Filings in Silicone Oil Suspension ( Iron filing field detector ): visualizing the invisible- the magnetic field lines around a horseshoe magnet. In the presence of a magnetic field, ferromagnetic materials (such as iron) temporarily become magnets. Here the iron filings become dipole magnets and link up and align like tiny compass needles to follow and reveal the magnetic field lines associated with the permanent magnet underneath. Viscous silicone oil temporarily keeps the iron particles suspended yet allows for rotation and repositioning under the influence of the magnetic field.

 

Polarizing Filter Black Wall Illusion

Amazon lists acrylic tubing at a reasonable price: get a 2 foot long tube with an inner diameter of 1.5 inches for about $17 US. This will accommodate a large marble for the demonstration. 
From Amazon: BUY NOW Acrylic Tubing 

For a 1.5 inch inner diameter (3.8 cm) tube you will need a 10 inch (25.4 cm) wide sheet to complete a cylinder inside the tube. 
From Educational Innovations: BUY NOW Polarizing Film

Polarizing Filter Black Wall Illusion: two sheets of polarizing film (with polarization axes oriented at 90 degrees to each other) create this illusion inside an acrylic tube. Physics magic!

Van de Graaff Generator

This device is sold as the "Static Shocker" hands on lab. Get one here for $8.95! : 
From Educational Innovations: BUY NOW Static Shocker Mini Van de Graaff 

The device can use an empty aluminum can for the top electrode which works- but this $9 hollow steel sphere looks and works even better- I used the 80mm sphere: 
From eBay: BUY NOW Hollow Steel Sphere 

Van de Graaff Generator: this miniature electrostatic generator can create potentials of more than 50,000 volts allowing sparks to jump a couple centimeters through dry air. Similar physics to the sparks created when shoes scuff on carpet, a moving rubber dielectric belt carries electrons away from the top sphere leaving it positive charged- as can be seen by the electrostatic repulsion of some Mylar strands. A small battery powered 3V motor drives the belt via the bottom pulley in this unit that costs less than $10 US.?With appreciation to @educational_innovations for sending me this device! 


Top Secret

This physics toy top is available here: 
From eBay: BUY NOW Mystery Spinning Top 

From Amazon: BUY NOW Mystery Spinning Top


The amazing green magnetic viewing film is also available: 
From Educational Innovations: BUY NOW Magnetic Field Viewing Film 

Here is the 1974 patent showing the very simple circuit of this device. The spinning dipole (the top itself) induces a current in one of the coils, and this current is fed to the base of the transistor turning the electromagnet on when the top is near. 
 

"Top Secret": this top will stay spinning for more than a week- because it is actually a motor! The top is a dipole magnet (as revealed by Magneview film) and the base has an electromagnet that gives the dipole a push when the top comes near the center. An ingeniously simple circuit consisting of only a battery, a coil, and a transistor, is activated when the spinning magnet nears the coil turning on the electromagnet to give a boost to the spin of the magnetic top.

Simple Polariscope

This kit has everything needed to make your own polariscope: 
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! 

Simple Polariscope: polarized light reveals the hidden rainbows due to internal stresses imposed on polymer materials such as these pieces of polystyrene flatware, a technique used to model stress distribution patterns in engineering. Place the polymer samples between two linear polarizer filters and the internal stresses created by the molding process during manufacturing produce colors through birefringence due to photoelasticity.

Magnetic Sand Hourglass

Get one from these fine sources: 
From Educational Innovations: BUY NOW Magnetic Sand Timer 
From Amazon: BUY NOW Magnetic Hourglass 

Magnetic Sand Hourglass: 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, creating interesting patterns that reveal the magnetic field lines. 


Revolution

This vintage toy can sometimes be found on eBay. 
Quality models of the modern version of this physics toy are still available 
From Educational Innovations: BUY NOW Magnetic Levitator 
From Amazon: BUY NOW Magnetic Levitator 

Revolution: vintage 2D magnetic levitation- permanent magnets can only produce static equilibrium along two dimensions- here a glass mirror constrains the third dimension, and makes for a nice bearing surface for rotation. This item was sold in the 1990s in mall shops such as Natural Wonders. 

Happy/Sad Spheres

Get a set here: 

From Educational Innovations: BUY NOW: Happy/Sad Balls

Happy/Sad Spheres: one ball bounces the other stops dead. The bouncy ball is made of neoprene rubber and exhibits high elasticity. The "sad" ball is made of polynorbornene and converts almost all kinetic energy into heat and sound- approximating/demonstrating the case of a completely inelastic collision. Polynorbrene is used in vehicle bumpers, for soundproofing, vibration damping, and other applications where recoil motion is unwanted.


Static Spheres

Get this inexpensive device here:

From Educational Innovations: BUY NOW: Static Spheres

Click here for other static electricity devices

Static Spheres: triboelectric effect toy. The red acetate spheres are given an acquired net negative charge, and their mutual repulsion allows them to jump a centimeter or more as charge is manipulated on the PET plastic container. Bringing an object near the container momentarily moves electrons (charge) around creating repulsive forces (sphere v. sphere) and attractive forces (spheres and container) resulting in the observed motions. The red spheres interact with each other without coming into physical contact (as shown in 240 fps slow motion) as like charges repel. Shaking the system a bit allows the red spheres to pick up charge in the first place by colliding with the container.

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 

Other interesting engines available here: Simple Heat Engines

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. 

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! 


Magneview Flim

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

Magneview Flim: making the invisible visible and revealing the hidden physics of our everyday world. Microscopic cavities in this green film are filled with oil and tiny flakes of Nickel metal- like compass needles, the flakes align with the magnetic fields revealing the complexity of the north and south pole domains of these magnets. Two of the disk magnets have multiple north and south poles and look like gears with teeth- these are rotors from small motors. 

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?