Physics on Etsy!

Perpetual Motion Simulator V2.0

This new demonstration transparent model is available here:
From Amazon: BUY NOW: Transparent Perpetual Simulator

Get the original here:
From Etsy: BUY NOW: Perpetual Marble Machine (reccomended seller: William Le of BackToNatureDecor)

Note: this site contains affiliate links for which I may be compensated

Perpetual Motion Simulator V2.0: a version with a transparent casing that reveals the sophisticated mechanism and electronics behind the newest “perpetual motion” toy that hit the internet a couple years ago. The original version was expertly crafted to make the base look like a block of wood (see post from November), but here we see a battery, a coil, a set of large capacitors, and a blue sensor unit along with circuit boards. The sensor detects the descending metal ball and then in an amazingly short amount of time the circuit discharges the capacitors through the coil to produce a magnetic pulse that accelerates the ball. Still looking into what kind of sensor is used- but this circuit is an excellent reminder that when someone claims a perpetual motion device the question to ask is “where’s the battery hidden?”

See Steve Mould's excellent video for details on the Perpetual Motion Simulator Circuirtry 

Trisected Sphere Puzzle

Get one here (color of your choice):

From Etsy: BUY NOW: Trisected Sphere Puzzle

Note: this site contains affiliate links for which I may be compensated

Trisected Sphere Puzzle: three identical pieces interlock to form a ball in this elegant 3D printed dissection puzzle. The sphere is sliced following a helical path from one pole to the opposite pole, creating a smooth disassembly and reassembly.

See other fun geometric puzzles here: dissection puzzles

South Pointing Chariot

An excellent and affordable 3D printed version available here:
From Etsy: BUY NOW: South Pointing Chariot

Or get the files to print one yourself: From Printables: South Pointing Chariot 

Note: this site contains affiliate links for which I may be compensated

South-Pointing Chariot: no matter the direction carriage moves, or how many times it turns, the arrow remains pointing south (or whatever direction it was placed initially). This amazing mechanism utilizes a differential gear train, the famous device used in cars to allow wheels to rotate at different rates when cornering. Differential gear trains have the following property, the rotation rate of one shaft is equal to the average rotations rates of the other two shafts. Each wheel of this device drives one of two input shafts, with one geared in reverse, so that if the carriage is moving in a straight line the two rates average out to zero, and the output shaft connected to the top arrow stays stationary. If, however, the carriage turns a corner, one wheel then rotates faster, and the average rate then turns the top arrow at exactly the right rate to stay pointing in the same direction. This design is the most likely basis for the ancient (about 200 CE) Chinese South-Pointing Chariot, described in historical manuscripts which describes a statue on the carriage with an arm extended pointing South. This version was designed by software engineer and tinkerer extraordinaire Matt Keveney, and expertly printed by my friend Alex Kling. 


Moon Globe with Raised Relief

Get this incredible globe here:

From Etsy: BUY NOW: Terrainian Space Globes

Moon Globe with Raised Relief: explore our Moon in your own hands with this incredibly detailed lunar globe where all surface features have been rendered in 3D topographic relief- where the mountains and craters actually cast shadows. Note how the selenography of the far side is radically different from the familiar near side- with no flat maria plains- and craters stacked upon more craters. Humanity has only known what the far side looks like since 1959 when the Soviet spacecraft Luna 3 took the first photos, and the Moon’s full map was completed via NASA’s Clementine orbiter in 1995- the data upon which this globe was made. Shown also are the six Apollo landing sites where humans have left footprints in the lunar regolith. This globe is made by Jeff Hobbs of Terrainian Space Globes by a process of precision CNC machining and cold casting techniques, complete with space-age look base stand. 

Chiral Aperiodic Monotile Puzzle

Get this amazing puzzle set here:
From Etsy: BUY NOW: Specter Tile Set by Nervous Syestem

Note: this site contains affiliate links for which I may be compensated

Read the published paper: A chiral aperiodic monotile

Chiral Aperiodic Monotile: these puzzle pieces are all identical in shape, based on special family of forms called “specters”, and are key to a major mathematical discovery in May of 2023. Specters will tessellate a plane to infinity, similar to how squares or hexagons can tile out with no gaps. However specters are identically shaped tiles which fill the plane aperiodically- if one tries to shift a part of a specter tiling, the shifted part will not align or match up with any other part of the same tiling- all the way out to infinity! The fact that aperiodic tessellations exist at all is pretty amazing, and Sir Roger Penrose (Nobel prize in physics 2020) is also famous for discovering a pair of regularly shaped polygons in the 1970s that tile in this aperiodic way. Specters were discovered by the same team of mathematicians (Smith, Myers, Kaplan, and Goodman-Strauss) who discovered “the hat” aperiodic monotile in March 2023, but the hat needs its mirror image to complete the tiling whereas the specter does not. An amazing development found only two months after the initial major breakthrough. Credit to the @nervous.system design team for modifying the specter into an interlocking puzzle piece form- and assembling these without gaps is a fair challenge! 

3D Phonotrope Spinner

Get this and other amazing phonotrope spinners here:

From Etsy: BUY NOW: Phototrope Animation Spinners 

Note: this site contains affiliate links for which I may be compensated

3D Phonotrope Spinner: spiders on a treadmill! When the rate of rotation matches the rate of the smartphone video process (wait for it) six animated 3D-printed spiders spring into motion. The laser cut acrylic, with precisely placed spiders, 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. Another fantastic design by Travis at aPyroDesign. 

 


Resin Art Dome Kalliiroscope

This item came from this Etsy shop:
From Etsy: SHOP NOW: Sensory Fidgets

A nice larger glass version is available from this trusted seller:
From PhysicsHack: BUY NOW: Vortex Dome Kalliroscope 

Note: this site contains affiliate links for which I may be compensated

Resin Art Dome Kalliroscope: visualizing fluid flow— rheoscopic fluid allows turbulent flow to be made visible with tiny flake crystals of mica catching the light. This fidget version of the kalliroscope is well constructed from poured resin that provides a tight seal- and note that great care was taken to prevent any air bubbles into the system. Rheoscopic fluids were developed by Paul Matisse in the 1970s to allow visualization of fluid motion. 

Bismuth Diamagnetic Trap Levitation

See more of Ernie's amazing creations here in his Etsy shop Element83 
From Etsy: BUY NOW Magnetic Levitation Sculptures

From Etsy: BUY NOW: Bismuth Maglev Rod

Note: this site contains affiliate links for which I may be compensated

Bismuth Diamagnetic Trap Levitation: neodymium cube magnet trapped between two pieces of strongly diamagnetic bismuth crystal. Diamagnetic substances only have magnetic fields of their own when placed in an external magnetic field from another source- here the cube shaped magnet supplies the field. Diamagnetic fields are pretty weak though so two large ceramic magnets are placed on each side and adjusted to help lift the cube magnet against gravity. Trapped in equilibrium by these magnetic fields, the slightest air currents can send the cube magnet dancing. Swipe to see a vertical trap based on the same physics. More amazing creations by Ernie McElhannon.

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 

Note: this site contains affiliate links for which I may be compensated

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!


Tenebrescence and Fluorescence 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

Note: this site contains affiliate links for which I may be compensated

Tenebrescence: a property of the mineral hackmanite which temporarily changes color when exposed to UV light- from pink/white to 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.

Tetrahedron Specular Hologram

Get this hologram brass spin top here:

From Etsy: BUY NOW: Tetrahedron Hologram Top

See other: specular holograms in my collection

Note: this site contains affiliate links for which I may be compensated

Learn more about (and how to make) specular holograms via this video by Steve Mould

Tetrahedron Specular Hologram: complex 3D images of rotating tetrahedrons arise from a surprisingly simple pattern of engraved circles. This brass disk has been machined with set of evenly spaced circles where the center of each circle falls on a triangle. The etched circular grooves 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. Two tetrahedrons appear for each point light source used. 

Cone of Apollonius 3D print

Get this inexpensive version here:

From Etsy: BUY NOW: Cone of Apollonius/ Conic Sections

Note: this site contains affiliate links for which I may be compensated

Cone of Apollonius 3D print: Slicing a cone with a plane will produce the famous curves known as the conic sections. Slicing at a right angle to the cone’s axis of symmetry produces a circle, and tilting the intersecting plane a bit produces an ellipse. When the plane is tilted parallel to the side of the cone the curve produced is a parabola, and tilting even further creates a hyperbola. The discovery of the mathematics demonstrated here are attributed to Apollonius of Perga from about 250 BC- thousands of years later Kepler, Newton, and others showed these conic sections to be intricately connected to many branches of physics such as planetary orbits and the optics of telescopes. 


Zulu Telephone Wire Bowl

Get similar weavings here:

From Etsy: BUY NOW: Zulu Wire Bowls

Note: this site contains affiliate links for which I may be compensated

Geometric Weaving: this Zulu telephone wire bowl, made in the traditions of South Africa, features a brilliant spiral pattern. The bright colors come from weaving strands of colored wires- the kind used to connect phones throughout buildings. This particular pattern inspired using a rotating base to display this bowl as kinetic sculpture.

Moire Kinetic Coasters

Get these well made illusions here:

from Etsy: BUY NOW: Laser Cut Wood Illusions 

Note: this site contains affiliate links for which I may be compensated

Moiré Kinetic Coasters: various patterns of overlaid curved spokes rotate and produce interesting illusions of motion via moiré interference effects. Each in this set of four coasters had a clear acrylic top upon which to place your drink, with intricate laser cut wood components underneath. The set includes a frame that couples each rotating center into cogs in a kinetic art gear train. Explore constructive and deconstructive interference patterns with this practical yet fun manipulable toy.

Map of the Universe: 2dFGRS

Get this laser etched scuplture here:

From Etsy: BUY NOW: 2dFGRS Crystal Sculpture

Note: this site contains affiliate links for which I may be compensated

Map of the Universe: actual astrophysical data with 221,000 laser etched dots, each dot representing a galaxy of stars and revealing the largest scale structures of our universe. This glass cube contains a 3D mapping of galaxies using the data from the 2dF Galaxy Redshift Survey completed in 2003 which revealed the large scale clumping and voids of galaxies, the true structure of our universe out to about 2.5 billion lightyears. The 3.9 meter wide telescope took about 5 years to collect the spectra of each galaxy in two thin slices of the sky, representing about 4% of the total. The Sloan Digital Sky Survey has since expanded on this to about 40% of the sky now mapped to 12 billion lightyears. Hold and explore this mapped chunk of the universe in your own hands! 


Steinmetz Solids

Get these as a 3D printed set here:

From Etsy: BUY NOW: Stienmetz Bi, Tri, and Quadcylinders

Note: this site contains affiliate links for which I may be compensated

Steinmetz Solids: 3D prints of the bicylinder- the space remaining from the intersection of two cylinders at right angles, and the tricylinder- the volume from the perpendicular intersection of three cylinders. Assemblies of acrylic rods illustrate the intersections that produce these shapes named after the mathematician Charles Steinmetz, who was also a physicist and electrical engineer with over 200 patents to his name from 1895-1915. Fun facts: The bicylinder casts a circular shadows along two orientations, and a square shadow perpendicular to those. The tricylinder casts a circular shadows along three orientations, and a hexagonal shadow along another three. 

The Alchemist

Bismuth levitation available here: 
From Etsy- Element 83: BUY NOW Magnetic Levitation Sculptures 
featuring amazing Bismuth Crystals, Jewelry, and Maglev Kinetic Art

Note: this site contains affiliate links for which I may be compensated

Circa 1981, Physicists transmute Bismuth to Gold: Particle accelerators make possible the ancient alchemist’s dream—but at a steep cost 

The Alchemist: cast from diamagnetic Bismuth, a neodymium cube magnet levitates trapped between the hands of the ancient scholar. Diamagnetic substances only have magnetic fields of their own when placed in an external magnetic field from another source- here the cube shaped magnet supplies the field. Diamagnetic fields are pretty weak though so a cylindrical neodymium magnet hangs above the figure and is adjusted to help lift the cube magnet against gravity. Trapped in equilibrium by these magnetic fields, the slightest air currents can send the cube magnet dancing. Although alchemists never succeeded in transmuting lead to gold, in 1981 physicists used the particle accelerator at Berkeley to shoot Carbon nuclei at thin foils of Bismuth- the resulting collisions did produced a tiny amount of Gold atoms! So modern nuclear physics, applied to the element Bismuth, finally accomplished the aspirations of the alchemists. ?Another amazing creation by Ernie McElhannon. 

Tunnelscope: Circular Mirror Kaleidoscope

Tunnelscope kaleidoscopes of many designs available here:

From Etsy: BUY NOW: Tunnelscopes

Note: this site contains affiliate links for which I may be compensated

Tunnelscope Circular Reflection Kaleidoscope: in this novel design a straight length of transparent acrylic rod provides the reflective surface, and two wheels filled with resin and interesting shapes of colored glass can each be turned separately to produce a flow of psychedelic patterns. The physics of refraction and total internal reflection allows for multiple reflections of the images down this light pipe “tunnel”, in essence providing a near perfect circular mirror design. A creation of kaleidoscope innovator and artist Roy Cohen, and made from polished brass, cast acrylic, and colored glass.