Recent Posts

The Levitron

Levitron Tops were produced in the 1990s and are out of production and getting harder to find. Some models are still available here: 
From eBay: BUY NOW 
Levitron Top 

The Levitron: spin stabilized magnetic levitation- will fly for about 3 minutes or more per launch. The spin rate of the magnetic top must be just right for flight, not too fast or too slow. Air resistance and dissipative interactions between the magnets gradually slow the spin rate and the top falls. Interestingly trapping the top requires precision - the weight of the top must be adjusted to within 1 gram to achieve equilibrium between the pull of gravity and the magnetic repulsion from the large donut shaped magnet in the wood base. Repost of my favorite physics toy in my collection.

Impossible Bolt

Only available from these aritist/craftsmen: 

From Etsy: BUY NOW: Impossible Bolt & Nuts

Impossible Bolt: one nut threads on clockwise as normal- the other threads on counterclockwise on the same bolt! Not impossible- but carefully engineered and machined. Swipe for partial hint on mechanism. This puzzling curiosity was inverted by Scott Eliott and machined in solid brass by puzzle crafters Steve Nicholls and Ali Morris of TwoBrassMonkeys.

Newtons Yo-Yo

Get a set here: 
From Educational Innovations: BUY NOW Newton's Yoyo 
 

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.


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. 

Corona Discharge Trajectories

Mini Tesla coil with wire end attachment: 
From Amazon: BUY NOW 
Mini Tesla Coil 


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

Click this link for more information and uses of this mini Tesla Coil 

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. 

Coupled Pendulums

This vintage device was produced in the 1970s but is not hard to build. Here are (somewhat hard to find) steel balls with holes that will work nicely to construct these pendulums: 
From Amazon: BUY NOW Drilled Spheres 

See my other physics toys featuring pendulums

Coupled Pendulums: kinetic energy transfers between the pendulums in a complicated but cyclic way due only to the connecting string. If the two on the left are set to swing, soon the middle sphere is at rest while the two outside swing, then the one on the far left comes to rest and it starts the pattern over on the right. The pattern repeats until the initial energy is dissipated by friction. This desk toy was manufactured in the 1970s with the somewhat unfortunate product name "Mystery Swinger". 


Kostick Stars

Two versions available here: 
From Art of Play: BUY NOW 
Kostick's Stars 


Here is the detail of the connections of the 6 star from the patent document: 
 
Learn more about John Kostick here: John and Jane Kostick handcrafted mathematical constructions

Kostick Stars: The geometric forms of these kinetic sculptures snap into place due only to the balanced tension forces between thear slightly bent bronze wires. The large star is comprised of six struts, each made of 5 wires, which are made to intersect and weave though each other with beautiful geometric regularity. Similarly the small star has 4 struts each made of 3 wires. The ends of the 6 struts of the large star become the 12 vertices of an icosahedron, and the ends of the 4 struts of the small star point to the 8 corners of a cube. Both stars can be collapsed along many of the symmetry axes. Invented and patented in 1970, these stars are still produced and sold by artist and designer John Kostick. 

Ambiguous Superhero Object 

Available now- 3D printed ambiguous object Illusion:

From Amazon: BUY NOW: Superhero Ambiguous Object Illusion

From eBay: BUY NOW: Superhero Ambiguous Object Illusion

More of this type hereAmbiguous Object Illusions on @physicsfun 

Ambiguous Superhero Object: A very fun fan art 3D print which makes use of the ambiguous object illusion invented by mathematician Kokichi Sugihara- a clever combination of reflection, perspective, and viewing angle. Printed and sold by 3DNY Design. 

Gifeez: Modern Phenakistiscope

This amazing toy for under $10: 

From Amazon: BUY NOW: Gifeez Animation Toy

Gifeez: a modern zoetrope type device with built in strobe light to explore the physics and psychophysics of motion animation- still images flashed in rapid succession produces the illusion of motion through persistence of vision. This inexpensive device has two modes: 1) the strobe frequency is set to various ratios of the spin frequency creating fascinating motion of abstract geometrical images, and 2) the strobe is set to animate simple cartoons. When the image flash rate is above the flicker fusion frequency (approximately 16Hz) we perceive fluid motion- the basis for all movies and TV. This device includes a centripetal switch that turns on the strobe and a motor that keeps the disk spinning for a couple minutes and comes with 15 printed double sided disks and a few blanks to allow for your own designs. 


Diamagnetic Racetrack

Diamagnetic levitation kits are available here: the racetrack magnets are a bit pricey though! 
From eBay: BUY NOW Diamagnetic Levitation Kit 

Educational Innovations has this affordable starter kit: 
From Educational Innovations: BUY NOW Diamagnetic Levitation Kit 

Diamagnetic Racetrack: thin pyrolytic graphite sheets levitate above powerful magnets. A set of five concentric neodymium magnets, alternating N-S-N-S-N comprise the racetrack and form the trapping field. Diamagnetic substances develop temporary repulsive magnetic fields only when they are in the presence of a magnetic field from some other source. Graphite of this sort is the most diamagnetic substance known.

In-Feed Google 3

Eclipse

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

Eclipse: A diamagnetic levitation sculpture by Element83. 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. ?Another amazing creation by Ernie McElhannon. 

 


Tea Candle Steam Engine

Get one from these fine sources: 
From Educational Innovations: BUY NOW Tea Candle Steam Engine 
From Amazon: BUY NOW Tea Candle Steam Engine 

Tea Candle Steam Engine: a functional piston steam engine complete with boiler and flywheel. Takes about 2 minutes to get going after the candle is lit. The invention that powered the industrial revolution on a desktop! Made by Wilesco. 

Impossible Jar with Golf Ball

Get this "impossible" jar and other amazing things from this shop:

From Etsy: BUY NOW: Impossible Jar & Golf Ball

Impossible Jar with Golf Ball: a regular off the shelf golf ball somehow trapped within a standard glass jar. Neither the ball nor the jar were cut or glued in the fabrication process. The puzzle aspect is to consider how this object was produced (again, I have some theories- but I do not know the secrets of this artist). This incredible piece was made by craftsman and artist Nathan Nickerson, and comes with the golf tee display stand (a nice touch!)

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.


Tesla’s Egg of Columbus

PhiTOPs are available in Aluminum, Brass, and Copper (most conductive!): 
From Etsy: BUY NOW PhiTOP in Copper 
From Etsy: BUY NOW PhiTOP in Brass 
From EI: BUY NOW PhiTOP in Aluminum 

Click here for more on the PhiTOP and using magnetic induction to spin it up. 

Tesla’s Egg of Columbus: a copper ellipsoid egg (PhiTOP) mysteriously spins and stands upright in this modern version of Tesla’s famous demonstration from the 1893 World’s Fair in Chicago that first showcased the principles behind wireless power transfer and his AC induction motor. Rotating magnetic fields from under the wooden platform induce electric eddy currents to flow in the copper PhiTOP- these currents then create their own magnetic field which oppose the initial fields underneath and pushes the PhiTOP to spin. This version differs from Tesla’s in that the rotating magnetic fields are created by, well, a pair of rotating neodymium magnets (revealed by lifting the top platform in this model). Credit to astrophysicist Kenneth Brecher, the creator of the PhiTOP, and this unique means of using a common lab magnetic stirrer to create the induced currents. Finally, the ellipsoid top stands up vertically (when spun with sufficient rotational velocity) due to physics similar to that of the tippe-top. 

Gas Collection for Emission Spectra

I made the display holder and I got this set of gas tubes here (about $7 per tube): 
From eBay: BUY NOW 
Gas Pure Element Samples 

Here is the miniture tesla coil used in the video:
From Amazon: BUY NOW: Tesla Coil

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

Gas Collection for Emission Spectra: 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 only glows when very near the coil where the field is most intense whereas Neon and Helium have the lowest breakdown voltage and begin to glow many centimeters away from the coil. 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. The Krypton tube also exhibits interesting oscillations with this particular Tesla coil.