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.

Magentic Dandelion 

Here is a very powerful NdFeB neodymium magnet that will work withlarger nails: 

From Amazon: BUY NOW: Neodymium Disk Magnet

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

Magnetic Dandelion: through ferromagnetic interaction these iron rich nails temporarily become dipole magnets in the presence of an intense magnetic field from a 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 becomes 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. 

Electric Motor

Get this easy to assemble kit here: 
From Educational Innovations: BUY NOW Simplest Motor Kit 

Electric Motor: in its simplest form!- coil, magnet, and battery. The wire of the coil has an insulating coating- and this coating is carefully scrapped off one side on each end. When current passes through the coil it becomes an electromagnet and the permanent magnet repels it making it spin- as it turns the currents goes on and off depending if the copper posts are in contact with the bare wire (current on) or the still insulated wire (current off). I have motors with fewer parts- but they operate on more complex principles.

Magnetic Influence on Aluminum

For this demonstration stronger magnets work best:
From Amazon: BUY NOW: Neodymium Magnets

Here is a good small turntable with bearings: 
From Amazon: BUY NOW: Spinning Base

Magnetic Influence on Aluminum: physics puzzler- spin a magnet under a beer can suspended by a thread, and the can will turn. Why? Aluminum is not ferromagnetic, and as shown, magnets are not attracted to the can.  So how does a spinning magnet influence the can to spin? 




Answer: the can spins due to eddy currents induced in the conducting aluminum due to the moving magnetic fields underneath. The eddy currents make the can into a temporary electromagnet that then interacts with the magnets below according to the famous law by Lenz.

Self-Propelled Homopolar Motor on Aluminum Foil Racetrack

I used neodymium disk magnets, small end = 1/2" diameter, Large end = 3/4" diameter. 
From Amazon: BUY NOW Disk Magnets for Simple Motor 

Foil Runner Motor assembly diagram: 
Self-Propelled Homopolar Motor on Aluminum Foil Racetrack: A favorite DIY physics toy where disk shaped neodymium magnets supply the static magnetic field for this motor and become the wheels of a very simple vehicle with an AAA battery as the energy source. As soon as both ends make contact with the conducting aluminium foil an electric current will flow which in turn induces a magnetic field underneath the battery assembly. This induced field will then interact with the neodymium magnets on each end causing them to spin- a wonderful example of a motor with minimal components. The racetrack is a cardboard circle from a pizza box covered in kitchen foil.

PDLC Electric Field Induced Transparancy

Get this device here:

From Amazon: BUY NOW: PDLC Smartwindow Sample

and click here for the balancing dragon toy

PDLC Electric Field Induced Transparency: when a voltage is placed across Polymer-Dispersed Liquid-Crystal film, long skinny molecules align with the electric field allowing light to pass through without scattering- with the field off the molecules thermally randomize and then do scatter the light passing through, producing a milky white translucent appearance. This sample of a “smart window” is powered by a 1.5 Volt AA battery and has very thin metallic coating on the front and back. A fun demonstration of electrochromic materials. 

"Magic Octagon" Challenge

Make your own with these nice wooden octagons:

From Etsy: BUY NOW: Laser Cut Octagons 

“Magic Octagon” Challenge: a puzzle of successive rotations. Which way will the orange arrow point after left and right rotations of the blue arrow? No trickery here- just the math of geometry, symmetry, rotations, and reflections and how our intuitions often fail us upon first attempts. Swipe twice for second challenge. From the mind of David Masunaga by way of Dan Meyer.

Simple Polarimeter

This DIY device is part of the polarization kit that you will get from a MEL Physics subscription:

Subscribe to: MEL Physics

Simple Polarimeter: Two linear polarizing sheets oriented at 90 degrees creates this device that reveals rainbows hidden within the patterns of polarization in the light transmitted by some common plastic objects. Just one of many amazing experiments from the MEL Physics science kit collection. Polypropylene is a clear transparent plastic comprised on long chain like molecules which interact with light wave orientation- when this plastic substance is heated to form things like utensils or containers, these long strand molecules lock in pattens of stress from the cooling, which are revealed as changes in color/frequency of the transmitted light.

Toy Themed Marble Run

Out of production but still available on eBay:

From eBay: BUY NOW: FAO Schwarz Marble Run

Toy Themed Rolling Marble Sculpture: marbles perform gymnastics as potential energy of gravity is converted to kinetic energy. This festive FAO Schwarz branded marble run features two powered conveyers including an Archimedean screw inside the toy rocket (one AAA battery and a small motor for each). 

Spirograph Animator

Get this amazing and inexpensive toy here:

From Amazon: BUY NOW: Spirograph Animator

Spirograph Animator: a turntable adds an ingenious embellishment to this classic math toy. When the centerpiece is put into rotation a strobe light turns on and the cyclic designs spring into a complex dance. Spirographs produce mathematical roulette curves called hypotrochoids, cyclical designs that repeat at varying integer multiples. When the strobe light frequency, and rotation frequency, match up with an integer multiple of one of the patterns, that roulette curve appears stationary while the other patterns stay in motion. Shown here is but one combination of many possible overlapping patterns that can be produced by the supplied set of gears and colored pens. 

Camphor Propulsion Boat

These vintage toys often available here:

From Etsy: BUY NOW: Camphor Craft Boats

From eBay: Search NOW: Champhor Craft Boats

Camphor Craft Miniature Self Propelling Toy Sailing Ship: this vintage toy boat is propelled by a difference in surface tension. Fluids will flow away from regions of lower surface tension (Marangoni Effect) and as the camphor mixes with the water at the stern of the boat a gradient of surface tension is created pushing the boat forward. Made in Cornwall England-swipe to see this 1960’s vintage toy in its original packaging. 

Light Pipe Sculpture

Get an affordable pre-bent light pipe demo here:
From Amazon: BUY NOW: Light Pipe Demo

Blue laser pointers (445nm) available here:
From eBay: BUY NOW: Blue Laser
but any color laser will work. 

Make your own abstract light pipe sculpture, an inexpesive heat gun is the only needed tool:
Materials from eBay: BUY NOW: Acrylic Rod
Tool from Amazon: BUY NOW: Heat Gun

Light Pipe Sculpture: internal reflection constrains most of the laser light to propagate along the bent acrylic rod- the physics of fiber optics. This abstract sculpture was created by applying a heat gun to a 3/8” diameter acrylic rod. The laser pointer used here is blue at a wavelength of 445nm.

Simple Polarimeter and Polarization Art

This DIY device is part of the polarization kit that you will get from a MEL Physics subscription:

Subscribe to: MEL Physics (click to see the contents of this great kit). 

Simple Polarimeter and Polarization Art: another amazing experiment from the MEL Physics polarization science kit. Geometric patterns of overlapping cellophane tape with color revealed when viewed with linear polarizing filters- create your own polarization art! This kit provides two linear polarizing sheets that when oriented at 90 degrees creates this device that reveals rainbows hidden within the patterns of polarization in the light transmitted by various objects. In the first video the layers of cellophane rotate the polarization of some light frequencies more than others. In the second video the polarimeter colorfully reveals the trapped internal stresses created in many plastics from their formation process (typically cooling of a liquid in a mold). All items shown included in this kit (plus much more). 

Invisible Ink and UV LED Pen

This item came to me in my Winter 2022 Curiosity Box subsciption:
Get (or give!) a Curiosity Box subscription here: JOIN NOW: The Curiosity Box

Get this amazing and inexpensive version of the Spirograph here:
From Amazon: BUY NOW: Spirograph Animator

Get a similar pen and UV light here: 
From Educational Innovations: BUY NOW UV Pen

Invisible Ink and UV Pen: this pen utilizes a clear ink that when dry is barely noticeable, but contains fluorescent compounds that reveals its presence under long wave ultraviolet light. This cool pen with UV LED light came in my @thecuriositybox yesterday where I applied it to make some hypotrochoid roulette curves with this pocket Spirograph set. 



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 eBay: 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. 

Impossible Braid 

Get this nice example of mystery braid here:

From Art of Play: BUY NOW: Impossible Braid Key Fob

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

See other Impossible Objects in my collection. 

Mystery Braid: challenge- how can three strands be braided if both sets of ends are connected? (swipe for reveal) A new addition to 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 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!



In-Feed Google 4

Wringing Guage Blocks

Guage block sets can be a bit pricy, but some fairly inexpensive pieces and small sets can be found for demonstrations and such:

From Amazon: BUY NOW: Gauge Blocks

Wikipedia has a nice description of Gauge Blocks and the Phenomenon of Wringing

Wringing Gauge Blocks: two blocks of metal (not magnets!) will stick together by a process called wringing if their surfaces are flat to high precision- such as these gauge blocks found in most machine shops. Here two blocks are forced apart with a snap, and then wrung back together with the characteristic sliding motion technique. Gauge blocks are flat to less that one millionth of a meter and are used by machinists for precision length measurements and calibration. The science of the wring force remains somewhat a mystery and no one has yet found a fully excepted physics description- but we do know that blocks will wring in a vacuum and that the force can be up to 30 times that of weight of the blocks. Fun physics from the shop!