Educational Innovations

Birefringence in Calcite

Get a sample here: 
From Amazon: BUY NOW Optical Calcite Crystal 
From eBay: BUY NOW Optical Calcite Crystal 

Get inexpensive polarizing filters here: 
From Educational Innovations: BUY NOW Polarizing Filter Sheets

Birefringence in Calcite: the speed of light in a calcite crystal depends on polarization- the refractive index is different depending on the polarization orientation of the light transmitted through it. As a polarizing filter is rotated 90 degrees, one image appears and the other vanishes, showing that the polarization orientation of the light of the two images is indeed perpendicular. In addition the elegant rhombohedral nature of calcite crystals is obvious in this sample. 

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.

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!

Harbottle Air Pressure Demonstration 

This item came to me in my Spring 2022 Curiosity Box subsciption:
Get (or give!) a Curiosity Box subscription here: JOIN NOW: The Curiosity Box

A nice glass version is available from this trusted seller:
From Educational Innovations: BUY NOW Harbottle Demonstration 

Harbottle Balloon Demo: a regular untied balloon remains inflated- one can even look down the neck of the balloon and see inside! Just blow up the balloon inside the bottle and then cork the hole in the opposite end- in so doing the inside of the balloon is experiencing the full force of air pressure, but the exterior of the balloon is protected from the crush of air pressure by the rigid wall of the bottle. Air pressure at sea level is 10.1 Newtons of force per each square centimeter of area (14.6 pounds per square inch). The bottle allows a pressure differential, pressure on the inside but much less on the outside of the balloon. The inside air pressure would lead to 12.5 pounds of force pushing outward on a 2 inch diameter balloon- more that enough to balance the elasticity of the rubber balloon material. Take the cork out and now both sides experience the same air pressure and the elastic force is no longer balanced. A fun demonstration reminding us that we live at the bottom of a deep sea of atmosphere! 

Repelling Marbles Puzzle

Get this affordable and fun kit here:

From Educational Innovations: BUY NOW Mystery Marbles Puzzle Kit 

Mystery Marbles Puzzle: a physics brain teaser (now available as a kit) what's going on here? Three glass marbles can move but stay separated in this liquid filled tube no matter the orientation- why do they not touch? Swipe for reveal of components. 

See also: Poly-acrylamide Polymer Vanishing Act


Fluorescence and Birefringence in Calcite

Get a sample here: 

From eBay: BUY NOW Optical Calcite Crystal 
From Amazon: BUY NOW Optical Calcite Crystal 

Get inexpensive polarizing filters here: 
From Educational Innovations: BUY NOW Polarizing Filter Sheets

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

Fluorescence and Birefringence in Calcite: two samples of calcite- each with different impurities that produce blue fluorescence for the small crystal and red fluorescence for the larger one under a 405nm violet laser. Also one can clearly see that the single laser beam takes two paths through the crystals- the speed of light in a calcite crystal depends on polarization because the refractive index is different depending on the polarization orientation of the light transmitted through it (swipe for demonstration). As a polarizing filter is rotated 90 degrees, one image appears and the other vanishes, showing that the polarization orientation of the light of the two images is indeed perpendicular. In addition the elegant rhombohedral nature of calcite crystals is obvious in this sample.

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.

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! 


Horizontal Hand Boiler

This device available here:

From Edicational Innovations: BUY NOW: Horizontal Hand Boiler

Horizontal Hand Boiler: liquid-gas phase transition. The boiling point of dichloromethane is slightly below body temperature and heat from a hand will induce vaporization of the liquid which increases pressure in one bulb pushing the red (dyed) liquid through the glass pipe to the other bulb. The process can repeat by switching the hand to the other side, but as both sides heat up the transfer is less vigorous. An inexpensive toy demonstrating phase changes and other thermodynamic physics.