Recent Posts

Labradorescence

Get a smaple of labbradorite here:

From Etsy: BUY NOW: Polished Labradorite 

Labradorescence: the unique luster given off by the mineral labradorite that appears as a glow emanating from below the surface of the polished rock. This iridescence is due to the Schiller effect, crystals that grow in very thin layers producing colors from the diffraction of reflected light. Labradorite is a feldspar mineral first identified in Labrador Canada.

Advanced Gyro: Hybrid Spinning Top

Get one from David Fowler's shop: 
From PhysicsHack: BUY NOW: Advanced Gyro
Made with extraordinary craftsmanship and high quality materials, and sold at a very reasonable price! 

Hybrid Gyroscope Top: the Advanced Gyro is a new design by @physicshack and in defiance of gravity this gyroscope can hang from a string attached only at one end. No pull cord needed, this unique design spins up via friction with a working surface (thin cardboard works well) and applying a circular motion to bring the rotor up to 1000s of RPM. Machined from solid stainless steel this top weighs in at about half a kilo, providing inertia that produces long spin times. 

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. For this 3D print, the maker Travis Quesenberry 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! 

 


Hero's Engine

This live steam engine is available here:

From EngineDIY: BUY NOW: Hero's Engine

Hero’s Engine: the very first steam engine ever devised, the Aeolipile is a radial steam jet reaction turbine, an a invention attributed to Hero of Alexandria in the year 1 AD. Water within the spherical container is heated to produce steam which exits through nozzles directed at right angles to the radial direction, and by Newton’s third law these jets produce a torque about the rotation axis. There is no historical record of this engine being put to practical use in ancient times- except perhaps as the world’s first physics toy!

Emission Spectra Gases on Radial Mount

I made the display holder and I got this set of gas tubes here (about $9 per tube): 
From Luciteria: BUY NOW: Gas Pure Element Samples 

From engineDIY: BUY NOW: Mini Tesla Coil
For the price, this is the best one on the market- and beautiful to look at in copper- and it comes with three accessories for the top. Please be sure to employ all appropriate safety precautions when utilizing any electrical circuity!

The mount is made by driling holes in this acrylic tube: 4" Acrylic Tube

The breakdown voltages of the elements featured in this post are described by Paschen's Law: 
 
Here is a excellent article with an overview of the physics of glow discharge and its application in lighting and other technologies. 

Click this link to see the mini Tesla coil in action

Emission Spectra Gas Samples: pure samples of hydrogen, nitrogen and five noble gasses are subjected to the high frequency pulsed field of a miniature Tesla coil. Each gas has a characteristic breakdown voltage and emission spectrum- note that Nitrogen has the highest breakdown voltage and begins to glow after the presence of my hand temporarily lowers the resistance to current flow for that tube. The color of each gas is due to a mix of the colors emitted from electron energy transitions specific to each element- the basis of spectroscopy. Notice also that the purple color of the brush discharge at the top of the Tesla coil matches closely to the color of the nitrogen sample, which makes sense as air is 78% nitrogen. 

The iTOP

Well engineered brass spinning toys by SiriusEnigmas:

From Etsy: BUY NOW: The iTOP 

From Etsy: BUY NOW: The PhiTOP

From Etsy: BUY NOW: The eTOP

From Etsy: BUY NOW: The PiTOP

The iTOP: inverting spinning disk- the equilibrium state for a spinning thing is often different from that of the same object when stationary. When spun, the iTOP almost instantly inverts to raise its center of mass (shown in slow motion because it happens so fast). However, when the rotation speed decreases to a certain rate the system becomes unstable (shown again in slow motion) and flips again before going into a rolling/spinning motion like a coin. This top completes the set of four spin tops by astrophysicist Kenneth Brecher, all made of polished brass and themed on a mathematical constant. Swipe to see a demonstration of each: iTOP (square-root of -1), PhiTOP (golden ratio, φ), eTOP (base of the natural log), and the PiTOP (C/D of a circle, π). 

 


Electromagnetic Levitation Module

Get this kit here (comes complete as shown in my video):
From engineDIY: BUY NOW: Magnetic Levitation Module

The featured sculture is by Bathsheba Grossman, affordable and beautiful math art available here:
From Etsy: BUY NOW: Soliton Sculpture

Electromagnetic Levitation Module: this engineered control system uses adjustable electromagnets (four copper coils) and and two Hall effect magnetic field sensors (held firm embedded in white silicone) to levitate an 5cm diameter neodymium magnet platform about 3 cm in mid-air. A feedback loop informed by the Hall effect sensors allows fine tuning of the magnetic field to exactly balance the pull of gravity, and is powered by a standard USB connection. The platform also rotates, perfect for showcasing one of my metal 3D printed mathematical sculptures by Bathsheba Grossman.

In-Feed Google

Woodwork Rattleback

The amazing work of Emmanuel Péluchon can be purchased here:
From Boisselier.ca: BUY NOW: Fine Woodworked Rattleback

Inexpensive rattlebacks can be found here:
From STEMCell Science: BUY NOW: Rattlebacks 

Woodwork Rattleback: prefers to spin counter clockwise- If spun clockwise, a complicated combination of friction, precession, and instability induced vibrations transforms the rotational energy into into rattling (energy of oscillations) and then into rotational energy in the opposite direction. This behavior is related to an asymmetry in weight along the left/right symmetry axis- the dark wood is Apple which has twice the density of the light colored Basswood(Linden). This asymmetry in weight induces an instability, quite like the vibrations that arise from an unbalanced tire, that transfers the rotational energy to the intermediate rocking vibrations. This beautiful physics toy was produced by Emmanuel Péluchon.


Rheoscopic Sworld

Get a Sworld ball (choose a color) here:

From Amazon: BUY NOW: Sworld Rheoscopic Ball

Also- the best in rheoscopic kenitic art- see: the Vortex Dome

Rheoscopic Sworld: this nice example of fluid flow kinetic art uses rheoscopic fluid encased in flexible bubble of plastic to reveal the intricate motion of turbulence. A suspension of tiny flat mica crystals tend to align themselves at the boundaries where the fluid is moving comparatively faster or slower, making the typically invisible flow patterns visible. 

Sodalite Fluorescence 

Get sodalite-bearing syenite river stones here:

From Etsy: BUY NOW: Sodalite Glow Rocks

You will also want an awesome UV flashlight like this one:

From Amazon: BUY NOW: High Power UV Light

Sodalite Fluorescence: in daylight this rock looks like an ordinary river stone, but when illuminated with long wave ultraviolet light, patches of the mineral sodalite shine in bright orange glow. These stones are comprised of sodalite-bearing syenite, where syenite is a course grained igneous rock similar to granite but deficient in quartz. Found on the shores of Lake Superior- discovered in 2017 by Erik Rintamaki.

 

Square Dissection Puzzles

Get these and other well made disection puzzles here:

From Etsy: BUY NOW: Square Dissection Puzzles

These puzzles are expertly laser cut and sold by GamesEfce. I spray-painted the pieces of mine to better show the shapes and relationships for the video. 

Square Dissection Puzzles: a square can be cut (dissected) into polygons and then reassembled into other regular polygons. Shown here: an equilateral triangle, a pentagon, and a hexagon. These are the record holders for smallest number of pieces needed: triangle (4 pieces by Henry Dudeney 1902), hexagon (5 pieces Paul Busschop 1870s) and pentagon (6 pieces Robert Brodie 1891). Fun fact- It is not known if any of these records are the smallest possible, no mathematical proofs yet exist on this question.


Ferromagnetic Interaction

Here is the NdFeB neodymium magnet used in this video:

From Amazon: BUY NOW: Neodymium Disk Magnet

Please use cuation when handeling strong magnets like this one. Small nails, paperclips, staples and other houlshold object made with iron will interact interestingly with the magnetic feild. 

Ferromagnetic Interaction: iron rich nails temporarily become dipole magnets in the presence of an intense magnetic field from a large neodymium super magnet. Here the neodymium disk magnet is set with its north pole pointing up, so the point of each nail becomes a south pole (repelling each other) and the head of each a north pole. Imbued with these temporary induced fields, the nails will try to align themselves with the neodymium dipole’s field like compass needles, and the nails will interact with each other in interesting ways.

Corona Discharge Trajectories

Mini Tesla coil with wire end attachment- get one here: 
From engineDIY: BUY NOW: Mini Tesla Coil

Long exposure image captured using this Slow Shutter app: 
 
From App Store: BUY NOW: Slow Shutter Cam 

Corona Discharge Trajectories: the ejected electron stream propels the end of a thin wire connected to a miniature Tesla coil. The corona discharge creates a glowing plasma at the end of the wire, but also imparts momenta that pushes the wire’s end into a final state circular orbit. The more interesting behavior occurs during the initial transient orbits which seem to be hypotrochoid type curves beautifully captured here using the Slow Shutter app. Please see seven posts back for details about this mini Tesla coil. 

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! 


1790 Terrestrial Globe by Mova

Available for all the planets and several versions of Earth: 
From Amazon: BUY NOW 
Mova Globes: all types 

From Amazon: BUY NOW 
Mova Globes: 1790 Terrestrial

From eBay: BUY NOW 
Mova Globes: all types 

Octopus Stand available here:
From pyrofarms: BUY NOW
OctoStand in Metal

1790 Terrestrial Globe by Mova: rotating counterweighted globe sealed within a clear liquid filled acrylic sphere. The rotation in a Mova globe is powered by light that shines through the semi-transparent map image on to solar cells within the globe which drive a motor. But what does the motor push against to maintain the rotation? Believe it or not it uses magnets to push against the Earth's magnetic field like a compass needle. Wonderful physics of all kinds in the design of this clever device. The featured map is a faithful recreation of a globe famous for its accuracy at the time by Giovanni María Cassini and highlights the voyages of James Cook.

 

Salt Fractionation

All the ingredients are available from your local market/drugstore. The trick is to find a dye that works for acetone, but will not color water- believe it on not blue glitter will color the acetone nicely and not change the salt water. Follow this link for details: 
ChemEd X: Blog of Prof. Tom Kuntzleman 

Of course Amazon has what you will need:

From Amazon: BUY NOW 
acetoneblue glitterfood coloring, cool bottle 

Salt Fractionation: two liquids that won’t stay mixed! Acetone (dyed blue) floats on top of the higher density salt water (dyed orange). Acetone usually dissolves in water through hydrogen bonding interactions, but solubility can be altered. In a process called “salting out” a sufficient amount of salt is dissolved such that the water molecules, which are much more attracted to the resulting Na+ and Cl- ions (through ion-dipole bonds), will then ignore the weaker acetone hydrogen bonds. This results in the spontaneous separation (shown here in real time) of the liquids no matter how well shaken up. 

Fluorescent Corundum (Ruby) in Matrix

Get ruby in matrix stones and jewelry here:

From Etsy: BUY NOW: Ruby Glow Stones

You will also want an awesome UV flashlight like this one:

From Amazon: BUY NOW: High Power UV Light

Corundum (Ruby) in Matrix: the pink/red mineral inclusions in this polished sphere of fuchsite are ruby crystals. Ruby fluoresces in bright red light when exposed to long wave UV light (such as a black light), creating the illusion that the sphere is lit from within. The same fluorescent property of synthetic ruby allowed creation of the first lasers.