Physics on Etsy!

Spiderman Hologram

This vintage hologram still available here:
From Amazon: BUY NOW: Spiderman Hologram

Similar vintage holograms are currently available on Etsy in limited quantities: 
From Etsy: BUY NOW Photopolymer True Hologram

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Spiderman Hologram: amazing 3D depth in this vintage hologram from 1995 encoded on thin red plastic and sold as a sticker- the image only appears if a light source is placed above the top of the composition at the correct angle. 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. 

Arrow on Mobius Strip

Get this fun demostration printed here:
From Etsy: BUY NOW: Mobius Strip with Arrow

Get the 3D print stl files here:
From printables: download now: Mobius Strip with Arrow

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Arrow on Möbius Strip: on the geometry of a Möbius strip a right pointing arrow points left after one trip around, a second trip restores the original orientation. This mathematical property is called non-orientability, and is also true of Klein bottles which I’ve posted about. I love how this 3D printed model, designed and produced by Wes Pegden, allows one to physically manipulate and intuit this somewhat obscure mathematical property. 

Earth Mass Black Hole with Space Warping Display Stand

Precision machined tungsten alloy spheres available here:

From STEMCell Science: BUY NOW: Tungsten Black Hole Replica

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Earth Mass Black Hole: this sphere of tungsten alloy has a diameter of 17.7mm, a precision representation of the size of the event horizon of a black hole with a mass equal to that of the Earth! If the entire mass of the earth could somehow be compressed to the size of this sphere, it would indeed collapse to a black hole with an event horizon defined by a Schwarzschild radius of 8.87mm. For comparison a black hole with the mass of the sun would be 6km across. This black hole replica is made of one of the densest materials available, a tungsten alloy with ρ=18.5 g/cm³ which produces a strange sensation when you hold it, with a weight of twice that of a ball bearing of equal size.


Eclipse Diamagnatic Sculpture

Click here to visit this amazing Etsy shop Element83 
Get a magnetic levitation sculpture here: 
From Etsy: BUY NOW Diamagnetic Levitation Sculptures 

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Eclipse diamagnetic levitation sculpture. Cast from diamagnetic Bismuth, a golden spherical neodymium magnet levitates trapped in a tunnel within the metal. Diamagnetic substances only have magnetic fields of their own when placed in an external magnetic field from another source- here the sphere magnet supplies the field. Diamagnetic fields are pretty weak though so a powerful cube neodymium magnet sits above the tunnel and is adjusted to help lift the sphere magnet against gravity. Trapped in equilibrium by these fields, any other magnet brought near will change the balance. 

 

Slinky on an Escalator Phonotrope Spinner

Get this amazing spinner here:

From Etsy: BUY NOW: Animated Slinky Spinner

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3D Phonotrope Spinner: slinky on an escalator! When the rate of rotation matches the rate of the smartphone video process (wait for it) 12 animated 3D-printed slinkys “spring” into motion. The 3D printed and precisely placed depictions of the famous toy is specifically designed to interact with the video process, similar to the animation effect of a flip book, but in a repeating cycle like that of the phenakistiscope, the 1833 invention that started moving media animation that lead to the development of movies and video. 


Liquid Pythgorean Proof

Get this inexpensive demo here:

From Etsy: BUY NOW: Pythagorean Theorem Proof Wheel

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Liquid Demo of the Pythagorean Theorem: a proof, in physical form, of one of the most famous equations concerning the sides of any right triangle. The area of a square with side c of the hypotenuse is indeed equal to the sum of the areas of the squares of side a and b. An excellent print and design by Kiegan Brewer of Printed Teacher Crafts. 

Impossible Braid 

Get nice examples of mystery braids here:

From Etsy: BUY NOW: Impossible Braid Key Fob

Here is a great video on how to make the mystery braid

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See other Impossible Objects in my collection. 

Mystery Braid: challenge- how can three strands be braided if both sets of ends are connected? A favorite in my collection of “impossible objects”, this leather key fob is braided from a single piece of leather, constructed by making two parallel slits but not cutting the ends. The solution (demonstrated here with red felt) is well known to those in the field of leatherwork- due to a twist of topology it’s possible to make this braid if the number of left strand over right crossings equals the times the right strand crosses over the left. Four strands braided this way is not mathematically possible, but 3, 5, or any odd number can be done! 

 

 

 

Natural Mineral Fluorescence 

Get ruby in matrix stones and jewelry here:
From Etsy: BUY NOW: Ruby Glow Stones

and find the sodalite bright orange fluorescent syenite here:
From Etsy: BUY NOW: Orange Glow Stones

You will also want an awesome UV flashlight like this one:
From Amazon: BUY NOW: High Power UV Light

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Natural Mineral Fluorescence: Four mineral specimens that emit a surprising bright glow under long wave ultraviolet light (from left to right): a clear calcite crystal glows pink, a carved obelisk of grey syenite with grains of sodalite(bright orange), a carved piece of green fuchsite with red ruby inclusions(red glow) and veins of white calcite(bright white), and a polished slab of lapis lazuli with speckles of the mineral hauynite (yellow glow). The colorful glow comes from complex quantum mechanical behavior where high energy UV photons are absorbed and then lower energy photons are emitted- the physics of fluorescence.


Acasta Gneiss

Samples of the oldest know Earth rock available here: 
 
From Etsy: BUY NOW Acasta Gneiss Specimens 

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Wikipedia has the details on Acasta Gneiss and see the next video and links for more geophysics fun! 

Acasta Gneiss: this polished sphere is a sample from the oldest known rock formation on Earth- rocks from this area are dated as old as 4.03 billion years old based on multiple and mutually consistent radiometric dating techniques. This gneiss is only found in the Northwest Territories of Canada and was collected by Yellowknife resident Mark Brown. 

Dual Phosphorescence

The UVA and UVC lamps used in this video are available here (well made and reasonably priced professional tools):
From WayTooCool LLC: BUY NOW: UV Lamps

Similar bowls of Mexican onyx can be found here:
From Etsy: BUY NOW: Stone Onyx Bowls

Get amazing phosphorescent calcite crystal samples here (those with a slight pink color will exhibit the glow): 
From Etsy: BUY NOW Optical Calcite Crystal
From Amazon: BUY NOW Optical Calcite Crystal 

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Dual Phosphorescence: this stunning “Mexican onyx” bowl is carved out of natural rock that contains phosphorescent calcite that glows in the dark after exposure to ultraviolet light. If exposed to longwave (lower energy) UV-A it glows green, but if exposed to shortwave (higher energy) UV-C it glows a ghostly blue. Phosphorescence is a quantum mechanical phenomenon where high energy UV photons are absorbed by electrons which are then boosted to higher energy levels. The glow comes from these electrons emitting lower energy photons (green or blue in this case) as they jump down through a series of energy levels back towards their ground state. These minerals also fluoresce and look strikingly different under UV illumination. 

 

 

Squirclusion (Square Circle Illusion)

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From Etsy: BUY NOW: Squirclusion

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Squirclusion (Square Circle Illusion): from one particular point of view this sculpture looks like a circle inside a square, from another, a square inside a circle- a matter of perspective! From other viewing angles one can make out that the underlying curves for each circle/square component are four identical segments of a parabola conjoined. Another reminder of how a single perspective can be misleading. This math sculpture is available as a 3D print, expertly designed and produced by Pyrigan Puzzles. 


Tenebrescence of Hackmanite

Get a sample here:
From Etsy: BUY NOW: Hackmanite Samples

You will also want a powerful UV flashlight:
From Amazon: BUY NOW: High Power UV Light

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Tenebrescence: a property of the mineral hackmanite which temporarily changes color when exposed to UV light to a deep shade of violet- photochromism from a naturally occurring mineral! Similar physics to phosphorescence (glow in the dark) the purple color fades back to normal over about half an hour, and the mineral can be put into this excited state over and over again by the UV rays of the sun, or this high intensity UV flashlight. Also- hackmanite has a bright orange fluorescent glow under UV.

TV Rock: Satin Spar

Get samples of Satin Spar here 
From Etsy: BUY NOW: TV Rock: Satin Spar

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Natural Fiber Optic Conduit: a special crystalline form of the mineral gypsum acts as a natural fiber optic image conduit in this square cut specimen with polished ends. Morocco seems to be the main source of this fibrous form, called satin spar gypsum, which exhibits pearl like luster and chatoyancy along two axes and transparency along the direction of the fibers. Each natural crystal microfiber extends the length of the rod and acts like a man made glass fiber where the index of refraction is just right to allow internal reflection to propagate light from one end to the other.

Iridescent Ferrofluid

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From Etsy: BUY NOW: Iridescent Ferrofluid 

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Iridescent Ferrofluid: the latest formulation of colloidal ferromagnetic liquid in a specially prepared water-alcohol suspension display cell. The interplay between magnetic force and surface tension allows for the strange shape shifting from rounded blobs to starfish like spikes. As with all ferrofluids on the market, the chemical formulation is kept a trade secret-- and the coloring on this version is spectacular!


Vintage Lenticular 3D Postcard: 2001

These vintage postcards are sometimes found here:

From Etsy: Search NOW: 2001 3D postcard

From eBay: Search NOW: 2001 3D postcard

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Lenticular Space Station V: an original 3D postcard from the year 1968 produced to promote the release of 2001: A Space Odyssey. The image features an orbiting transfer station that spins to produce a sense of gravity with spaceplanes seen en route. 3D cards such as these are comprised of an array of thin cylindrical lenses placed over interlaced multiple images so that each eye sees a different view creating the perception of depth. A vintage futuristic 3D card for perhaps the most futuristic movie of all time! 

Cosmic Window Kinetic Sculpture

Similar models often available here:

From Etsy: BUY NOW: Cosmic Window 

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Cosmic Window: mesmerizing kinetic art from 1996 featuring a rotating acrylic disk patterned such that illusions of radial motion are produced via moiré interference effects. Explore the math of constructive and deconstructive interference patterns with this vintage device manufactured by Rabbit Tanaka.

Harry Potter Mirror Shard

Get this lenticular cut-out here:

From Etsy: BUY NOW: HP MIrror Shard

The one in the video is modified: I covered the top in acrylic and backed it with aluminum tape to make it look more like silvered broken glass.

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Harry Potter’s Mirror Shard: A wonderfully creative implementation of the classic animation effect that uses an array of thin cylindrical lenses over interlaced multiple images. This lenticular image simulates the prop from the Deathly Hallows movies- and diehard HP fans will know the name of the other person in the mirror. The real magic of physics imitates Hogwarts magic!