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From Educational Innovations: BUY NOW Floating Ring Magnet Set
From Amazon: BUY NOW Floating Ring Magnet Set
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Magnetic Levitation in 1D: a stack of dipole magnets. Note how the spacing between any two magnets is proportional to weight of how many magnets there are above the gap. Gravity vs Magnetism.
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From Educational Innovations: BUY NOW Fire Piston Demonstration
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Fire Piston: rapid adiabatic compression creates enough heat to ignite and incinerate a small ball of cotton. Similar physics to how Diesel engines ignite fuel without a sparkplug. Adiabatic processes are those in which heat does not flow from the system to the environment, achieved here by the short duration of the compression- to get a flame it has to be done quickly with some force!
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From Educational Innovations: BUY NOW Newton's Yoyo
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Newton Yo Yo: Newton's 3rd Law states that action force equals opposite reaction force- the the green and yellow spheres have equal mass, so the forces of the collision provide accelerations that are equal and opposite such that the spheres trade places.
A wide variety available here, including some nice blown glass displays:
From Amazon: BUY NOW Radiometers
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Radiometers: three “light mills” from my growing collection of radiometers (now at 23 so far), including a double with two spinning flys in the same partial vacuum volume. Here the initial light is from a LED, and then a halogen incandescent bulb is turned on which activates the motion. This device goes way back, invented in 1873 by the famous chemist Sir William Crookes when he was investigating partial vacuum environments. Light heats up the “vanes” which then heat up the very thin gas left in the partial vacuum within the bulb- the black side of the vane is hotter than the silver side and any gas molecule that comes into contact with it flies off at a faster speed imparting impulse to the rotor.
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From Educational Innovations: BUY NOW Mystery Marbles Puzzle Kit
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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
Available from these fine sources:
From Educational Innovations: BUY NOW Dropper Popper
From Amazon: BUY NOW Drop and Pop Toys
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Drop & Pop: stored elastic energy. The elastic potential energy of the inverted rubber is released upon impact sending the half-sphere to hit the ceiling. Upon impact the popper reconfigures back to its original shape in the blink of an eye, shown here recorded at approximately 480fps.
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!
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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.
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From Educational Innovations: BUY NOW Electrostatics Kit
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Electrostatic Interactions: a triboelectric effect toy from the 1990s. The styrofoam spheres are given an acquired net negative charge by shaking the PET plastic container, and the foam beads are then attracted to the container wall but repel each other. (The foam balls pick up electrons when they strike the container walls.) A segment of PVC pipe also acquires a negative charge when rubbed with a paper towel, and here the foam spheres jump a centimeter or more when the pipe segment is brought near. In contrast, a segment of acrylic tube can acquire a positive charge, and will instead attract the styrofoam pellets as it is brought near the container. A demonstration of the invisible electric fields that are part of our everyday world.
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From Amazon: BUY NOW Optical Calcite Crystal
Get inexpensive polarizing filters here:
From Educational Innovations: BUY NOW Polarizing Filter Sheets
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Birefringence in Calcite: elegant rhombohedral crystals like this one form naturally, and notice that two images are seen when looking through it. 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.
Get these charming jellyfist here:
From EI: BUY NOW: Jellyfish Divers
Cartesian Jellyfish: increasing pressure in the water compresses air bubbles inside the plastic capsules, filling them further with water making them sink in this cute version of the famous Cartesian Diver toy. In this whimsical version the jellyfish also spin when the pressure is released as the water is channeled out of the capsule/head in a sideways jet. Pascal’s principle states that any change in pressure on an enclosed fluid (such as squeezing the plastic bottle) is transmitted evenly to every part of the fluid- the physics of hydraulic brakes! Named after the physicist and philosopher Rene Descartes.
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From Etsy: BUY NOW Iolite Sample
Affordable polarization filters and other polarization physics available here:
From Educational Innovations: BUY NOW Polarizing Film Kit
Note: this site contains affiliate links for which I may be compensated
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!
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.
Get this affordable dichroscope here:
From Amazon: BUY NOW: Dichroscope
Get dichroic iolite samples here:
From Etsy: BUY NOW Iolite Sample
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Dichroscope: many gemstones show very strong pleochroism- their color depends on the polarization of light as transmitted through the crystal. This dichroscope consists of two linear polarization filters at right angles to each other, and allows the user to see maximum contrast in color variation in gemstones. Shown here: sample of rough iolite, a polished iolite cabochon, a natural pebble of root beer tourmaline, and some pink tourmaline.
Many colors (and two sizes) to choose from:
From Amazon: BUY NOW Ooze Tube 3 Colors
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Ooze Tube Viscosity Contrast: this set of ooze tube timers comes with 3 mixtures of polyisobutene fluid, each with a different viscosity where green always wins the race: green (thin), yellow (medium), and red (thickest). A curious periodicity in the rate of flow is related to the formation of non-spherical bubbles as the air and fluid trade places (an hour shown in time-lapse). The fluid also displays the “liquid rope-coil effect” where the fluid thread coils and stacks as it lands on the pooling surface.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