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From eBay: Search NOW: Kalliroscopes 

Click this link for the best Kalliroscope currently in production and available.

Kalliroscope: rheoscopic fluid reveals the convection currents generated by the heat emanating from fingertips. Invented and produced by Paul Matisse in the 1970s, suspended microscopic flat crystals of guanine reflect light and allow visualization of the fluid's motion. This rheoscopic fluid is special in that the guanine crystals are the same density as the tetrachloroethylene liquid so the crystals never settle to the bottom making the fluid reactive to showing the slightest movement.

1 mole Carbon Block

Avialable exclusively from:

STEMCell Science Shop: BUY NOW: 1 mole Carbon Block

1 mole Carbon Block: by Avogadro’s famous number there are 6.022×10^23 atoms contained within a mole of substance- a very large number because atoms are very tiny. This chunk of graphite is precisely cut to weigh 12.011 grams, and hence when you pick it up you will have, in your hand, 6.022×10^23 Carbon atoms (to better than 1 part per thousand). That’s 602.2 billion, times a trillion, atoms! Such numbers are a challenge to conceptualize, so in collaboration with STEMCell Science Shop we introduce our specially cut and engraved “1 mole of Carbon Block”— to put an Avogadro’s Number of atoms on your shelf. 

Phenakistiscope Spinner Set

Get these amazing spinners from aPyroDesign;

From Etsy: BUY NOW: Animation Spinners

Phénakisticope Spinner Set: two spinners- one a laser cut and printed acrylic with a set of images similar to the animation design of a flip book (but in a repeating cycle)- and the second a black disk with thin slit openings. Spin them in opposite directions and then look through the black disk at the first to reveal an animated image, in this case a running stick person. The effect looks better in person in that the frame rate of the video capture process adds some artifacts. Using the second black disk like this turns the spinners into a phenakistiscope, the 1833 invention that started moving media animation that lead to the development of movies and video. Under very bright light the animation can also be seen using a smartphone camera in video mode, but the black disk allows one to see the animation without such technology.

Kinetic Wonder Rings

Assorted colors to choose from:

From Sling True: BUY NOW: Kinetic Wonder Rings

Kinetic Wonder Rings: a skill toy that features small rings that “roll” down a thicker steel ring while producing a distinctive ringing chatter sound as they go. Swiping the small rings gets them spinning and gives them angular momentum. Centripetal acceleration then keeps the inside of the small rings in contact with the steel ring so that they roll around as they descend (seen here in 240fps slow motion). The challenge is to rotate the large ring fast enough to keep the small rings in motion. A new take on the “Jitter Gyro Ring” 1990s skill toy craze, produced by Sling True toys.

Noble Gas Display and Tesla Coil

Get this display (Tesla Coil included!) here:
From Engineered Labs: BUY NOW: Noble Gas Display

Glowing Noble Gas Collection: five noble gasses are subjected to the high frequency electric field of a miniature Tesla coil. Encased in acrylic and carefully labeled, this spectacular display collection is the creative work of Tim and Cory Marriott of Engineered Labs Protoshop LLC- and each display comes with this Tesla coil! The high frequency/high voltage field of the coil transmits energy through the thick acrylic to excite the atoms of these gases, revealing the unique color of each gas, which is actually due to a mix of photon frequencies emitted from electron energy transitions specific to each element- the basis of spectroscopy.

Skybox Photopolymer 360 degree Hologram

These vintage holograms are available on eBay-- Batman, Superman, and others: 
From eBay: BUY NOW Skydisc Animated Hologram 

Skybox 360° Photopolymer Hologram: an amazing demonstration of holography- Batman from the Saga of the Dark Knight card series 1994. The 3D image by Skybox International comes to life by rotating the card to reveal an animated 360 degree view. Unlike photographs, holograms are recordings of the interference pattern of light waves, and this encoded information is stored in a layer thinner than a sheet of paper. Here the interference pattern encodes a moving 3D image which is then reanimated by illumination with a point source of light, and viewing from an appropriate angle. Looks even more stunning in person! 

Dancing Ferrofluid Device

Available here:
From Amazon: BUY NOW: Venom Sound Dancing Ferrofluid Display

Similar devices here:
From eBay: BUY NOW: Dancing Ferrofluid Display

Dancing Ferrofluid: a black magnetic fluid interacts with a variable strength electromagnet (like those found in speakers). A circuit supplies power to the electromagnet in proportion to the sound waves picked up by a microphone, the changing magnetic field- combined with the liquid surface tension of the colloidal ferromagnetic liquid- produces the captivating motion that keeps time with any music played. Featuring “12 String Thing”, composed and performed by my good friend T.D.Clark @tdclark67 

Caustic Projection Optical Element

This optical element is a component of this affordable Laser show device:
From Amazon: BUY NOW: Aurora Laser Show Projector

Get this beautiful new color of laser pointer here: 
From eBay: BUY NOW: 488nm Laser Pointer (Cyan)

Caustic Projection Optical Element: the intricate geometries of light due to refraction through various curved surfaces of transparent plastic. A 488 nm cyan laser pointer is refracted through an optical element with lumpy surface features which create this aurora/nebula effect. When light rays refract through a curved surface they concentrate into bright patches called caustics, often with cusp singularities (sharp points) and intricate threads of shadow. 

The PhoTOP

Get a PhoTOP from these fine vendors (comes with laser pointer!):

From Educational Innovations: BUY NOW PhoTOP 

Another amazing spinning device by Prof. Ken Brecher! Get his other spinning tops here:
From Etsy: BUY NOW: PhiTOP, PiTOP, eTOP, iTOP, DeltaCELT

The PhoTOP: phosphorescent glow illuminates the intricate path of a 405nm laser pointer beam on a balanced spinning disk. Let the disk set alone for a few minutes to allow the traces to fade- and repeat again and again to experiment making new patterns.

Kitty Cat Fireworks Lamp

Variations (bear, spaceman) avaialable from these sources: 
From Etsy: BUY NOW Fireworks Infinity Lamps
From Amazon: BUY NOW Fireworks Infinity Lamps

The Kitty Cat Lamp I found: here

Kitty Cat Fireworks Lamp: illusion of depth from multiple refections. This glass cat sculpture is partially coated inside and out with a thin metal layer. The metal layer is made thinner in a pattern of small circles and stars to produce iridescent colors through thin-film interference effects. When lit from within by white LEDs, multiple reflections on the curved contour of the glass creates the firework like spray of light and color.


The Physics of Tippe-Top Inversion

Get a nice tippe-top from this fine source: 

From Etsy: BUY NOW Flip Over Tops

Physics of Tippe-Top Inversion: spinning things often have surprising physics! In brief: friction with the surface 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. Inversion phase shown at 240fps- note the little hop the top takes as it goes on to its stem! 

Yellow Laser Pointer 

Amazing application of high resolution far field holograms. The only available source I know of for projection holograms at this high resolution is this supplier of industrial samples 
From Diffractive Optical Element Sample 

Get this yellow 591nm laser pointer here:
From eBay: BUY NOW: Yellow Laser Pointer
Need the main colors of laser pointer? Incredibly, you can get 3 (one of each) for under $20 (including S&H): 
From Amazon: BUY NOW: Red+Green+Purple Laser Pointer

Yellow Laser Pointer: diode lasers with wavelengths of 589 nm (golden yellow) have recently become less expensive, and will produce stunning far-field transmission holographic images as seen here. The production of yellow frequencies from diode lasers is very complicated and involves two separate infrared laser diodes (1,064 nm and 1,342 nm) which are directed through a nonlinear optical crystal that sums these two IR frequency photons, through a quantum conversion process, into the desired 589 nm photons. So amazing that such tech can fit within the length of a pen and be powered by AAA batteries! 


Half Seirpinski Octahedron Fractal

Get this amazing 3D print here:
From Etsy: BUY NOW: Seirpinski Pyramid

or print it yourself:
From Thingverse: Seirpinski Pyramid

Half Sierpinski Octahedron Fractal: this 3D printed math sculpture is one half of the sixth iteration of what is called “the octahedron flake” a 3D fractal based on the Sierpinski triangle. To make this fractal, on each iteration an inverted triangle is removed from the center of the previous triangle, and if this process is repeated indefinitely one gets the famous fractal. This 3D print used rainbow silk PLA to create the beautiful color gradient base on the .stl files by Rick Tu. Another example of math brought to life via 3D printing! 


Bouillant de Franklin (Hand Boiler)

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

Bouillant de Franklin (Hand Boiler): reversible liquid-gas phase transition device made famous by Benjamin Franklin who was one of the first to describe the physics of its operation. The boiling point of dichloromethane is slightly below body temperature - heat from a hand increases pressure in the bottom bulb pushing the green (dyed) liquid through the glass pipe to the top. A vintage handmade version from France.

Rolling Uphill Illusion

Availabel here:
From Etsy: BUY NOW: Uphill Ramp Illusion

or get the 3D print file here:
From Thingverse: Download Now: Uphill Illusion

Learn more: The amazing illusions of Kokichi Sugihara
See the many other Sugihara Illusions: in my collection

Rolling Uphill Illusion: the ball bearings seemingly roll uphill as if attracted by magnets of some kind. What’s going on? Swipe for reveal as it is truly a matter of perspective. A wonderful take on an illusion invented by Kokichi Sugihara of Meiji University. 3D printed by my good friend @zathras5 (Roger Key) from a file designed by Julian Hardy. 

Galton Boards: Small and Large

Available here: 
From Amazon: BUY NOW: Desk Galton Board 
From Amazon: BUY NOW: Display Galton Board (comes with an wonderful fact filled booklet). 

Galton Boards Large & Small: 6000 steel balls vs. 3000 in the compact version. Each ball has a 50/50 chance of going left or right at each branch such that the balls are distributed at the bottom by the mathematical binomial distribution (12 layers for the desk version, 14 layers for the deluxe). In addition the number of balls in each bin can be predicted by Pascal’s triangle, where the number on each hexagonal branch point represents the number of possible paths to reach that point from the top. Two extraordinary designs by Philip Poissant and the best version of the Galton Board since its invention by Sir Francis Galton(1894). An amazing demonstration of the Central Limit Theorem for the home or classroom! 

Triple Pendulum Chaotic Fidget 

Get this chaotic fidget spinner here:

From Amazon: BUY NOW: Triple Pendulum Spinner

Triple Pendulum Chaotic Fidget: This interesting spinner is made from stainless steel and features three physical pendulums each mounted with their own low friction bearing. In slow motion one can see the kinetic energy and angular momentum is transferred from one pendulum to another as the entire device rotates, with some spinning rapidly and others rotationally at rest- the intricacies chaotic motion, characterized by extreme sensitivity to initial starting conditions, tiny differences in how the system is released leads to dramatically different outcomes each time.

Specular Hologram Knot

Learn more about this art form here:
Zintaglio Arts: Holography by Matt Brand
Click here: to see other specular hologoraphy in my collectiuon.
The full details of the math in this process are described in this paper by Brand

Specular Hologram Knot: this complex 3D image is created by etched grooves that reflect a point source of light as glints, and each eye sees a slightly different pattern such that, via stereopsis, the shiny points appear to float above or below the surface. Complex mathematical equations must be solved to compute the shape of the thousands curves that are scratched into the surface of the metal plate. The artwork featured here is a creation of Matt Brand of Zintaglio Arts.