Recent Posts

Slow Dance

This finally crated kinetic art piece avaiable here: 

From Wonder Machines: BUY NOW: Slow Dance

From Art of Play: BUY NOW: Slow Dance

Slow Dance: a kinetic sculpture via induced vibration and high speed strobe lighting in which objects exhibit subtle and beautiful motion when mounted within this special frame. I love how the electromagnet, with its beautiful copper windings, is prominently featured at the bottom of the frame. Electronics within the frame send AC currents to the electromagnet which then pushes and pulls magnets on each side. These magnets are affixed to leaf springs to which feathers, flowers, and other objects are attached with elastic bands. The arrangement is then illuminated by LEDs set to strobe at just the right frequency to produce the slow dance illusion.

Impossible Wallet

Available here: 
From Amazon: BUY NOW Magic Wallet 

From eBay: BUY NOW Magic Wallet

Impossible Wallet: this pocketbook has a special double hinge that allows the wallet to be opened from either side, and leads to some rather nonintuitive consequences. Note that once inserted, the bill shows the same face independent of which way the wallet is opened. The construction of this magic (or flip) wallet is similar to the famous Jacob's Ladder toy.

Pocket Scintillator Kinetic Art

Logan sometimes has items for sale here:

From Etsy: BUY NOW: PocketScintillators

Pocket Scintillator Card: three sheets of seemingly random arrays of translucent colored pixels produce words and images when stacked- shift the stack of sheets and a second images appears! Innovative kinetic optical art by inventor, artist, software developer Logan Kerby @thanksplease who kindly sent me these cards encoded with @physicsfun themes.


Rocking Stork Drinking Bird

This artisitic version of the Drinking Bird available here:
From drinkingbird.eu: BUY NOW: Rocking Stork

Get a standard Drinking Bird from these sources: 
From Educational Innovations: BUY NOW 
Drinking Bird Engine 

From Amazon: BUY NOW 
Drinking Bird Engine 


Wikipedia has wonderful details about the rich history (and further descriptions of the operational principals) of the Drinking Bird
Rocking Stork: this species of drinking bird toy comes from the Czech Republic where each is crafted in blown glass by an artisan. This classic physics toy is a functional heat engine- cooling by evaporation at the head/beak leads to lower pressure in the top bulb, the pressure in the bottom bulb pushes the dichloromethane fluid (here dyed red) up the neck making the bird top heavy and the bird tips over dipping its beak and letting the fluid return to the bottom bulb. The process repeats, and as long as the top bulb stays wet and cooler than the bottom this heat engine will continue to cycle.

Balance Stacking Sculpture

Another wonderful desing by BinDesign- get one here in black or natural wood:

From Etsy: BUY NOW: Bin Design Balancer Puzzle

Balance Stacking Sculpture: a series of torques in unstable equilibrium complete this Calder-esque structure. As each component is added its weighted end balances all the others before it, with the initial small piece weighing about a gram or so. Remove the end piece and the whole structure comes down. Another wonderful design by artist Bin Xu.

The FluoroSphere

The kit includes the UV LED base, elegant glass sphere, and enough fluorescent gel for many repeat lights shows. 

From PyroFarms: BUY NOW: FluoroSphere

From Amazon: BUY NOW: FluoroSphere

The FluoroSphere: intricate and dynamic lights shows are produced within an elegant glass sphere as fluorescent dyes in mineral oil slowly mix into room temperature water. Ultraviolet LEDs (in the base on which the sphere rests) make the dyes glow brightly and reveal the initial nondiffusive mixing structure which includes the phenomena of drops, plumes, and other features of Rayleigh-Taylor instabilities. Shown here, slightly sped up, is the first 8 minutes or so of the process which takes up to half an hour to mix evenly. The green light is characteristic of the famous fluorescein dye.

 


Brief Intense Phosphorescence in Franklin Calcite

Nice specimens can be found here:
From eBay: BUY NOW: Fluorescent Mineral Specimens

Need a UV laser pointer? Get 3 lasers (one of each color) for under $10 (including S&H): 
From eBay: BUY NOW red+green+blue(UV) laser pointers

The flourescence can only be achived using short wave UV lamps whace can be expensive. Less expensive used devices are often found here:
From eBay: BUY NOW: Short Wave UV Lamps

Brief Intense Phosphorescence: a 405nm laser pointer excites the natural mineral Franklin calcite to briefly flash a red glow via brief intense phosphorescence(BIP) seen here as a trail of light following the violet laser dot on this spectacular specimen from the Sterling Hill zinc mine out of New Jersey. The second video shows the brilliant colors of fluorescence- Willemite fluoresces bright green and Calcite (with trace percent Manganese activator) glows pink/orange- seen from exposing the rock to short wave UV (less than 280nm) using a vintage Mineralight brand light.

 

Tension Integrity Icosohedron: Tensegrity

A nice version of this tensegrity icosohedron is sold as a toy for tiny tots: 
From Amazon: BUY NOW Tensegrity Toy 

 
I constructed this version by referring to the images and descriptions of tensegity on Wikipedia 

Tension Integrity Icosohedron: Six brass struts float isolated from each other but held in a stable configuration by a net of 24 connecting cables. I made this sculpture using hollow brass tubes and weaving through them a single strand of fishing line, which is connected after passing through each tube exactly four times. This configuration of three sets of parallel struts forms a Jessen’s icosahedron under tension, and was invented by the famous architect Buckminster Fuller in 1949.

Chaotic magnetic Pendulum

These chaotic pendula are still available on eBay!

From eBay: BUY NOW: Krazy Leg Pendulum

Chaotic Magnet Pendulum: adding magnetic forces to gravity gives this pendulum chaotic motion- not random, but very sensitive to slight differences in initial launch conditions. Swipe to see a particular launch path that begins with a semi-stable orbit but then goes chaotic, captured with an attached LED and recorded with a slow shutter app. Arranging the dipoles magnets on the base leads to different patterns of motion- here white attracts and black repels. This vintage device is from the 1970s and was sold by the name “Krazy Leg” by Rathcon Inc.


Dipole Magnet and Iron Filings

Get this set here: 
From Amazon: BUY NOW 
Magnetic Viewing Cylinder

Dipole Magnet and Iron Filings: visualizing the invisible- the magnetic field lines around a dipole magnet. In the presence of a magnetic field, ferromagnetic materials (such as iron) temporarily become magnets. Here the iron filings become dipole magnets and link end to end to follow and reveal the magnetic field lines associated with the permanent magnet within the hollow tube. 

Gravity Defying Nail and Magnet

Neodymium magnets will produce the largest gap when suspending a nail.
Please use exterme caution when handling these magnets. 

From Amazon: BUY NOW: Neodymium Super Magnet

Magnetic Defiance of Gravity: a nail suspended between a chain and a powerful neodymium magnet. Ferromagnetic attraction over a distance of many millimeters, and a reminder of the presence of the typically invisible electromagnetic forces all around us. Make your own with a paperclip, string, and a refrigerator magnet- or get a neodymium magnet and see how massive an object you can suspend in air. 

Tesla's Plasma Mug

This plasma mug was sold in the 1990s but can be found on eBay often:
From eBay: BUY NOW: Plasma Mug

An improved and beautiful version sold here:
From Etsy: BUY NOW: Plasma Mug

Tesla’s Plasma Mug: this double walled glass mug glows orange from the excitation spectrum of neon gas at low pressure. The base contains a high frequency transformer that generates high voltage electric fields (but at very low current) from 8 AA batteries- which excites the neon to glow, and also serves as a coaster. This crazy item was produced by Can You Imagine Toys in the 1990s- perhaps Tesla himself would have served a good beer in this mug! 


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.

Ambiguous Object Illusion Mug

From Etsy: BUY NOW Squirkle Mug Ambiguous Object Illusion 

These type of objects were invented by mathematician Kokichi Sugihara, and you can buy his books here: 
From Amazon: BUY NOW Ambiguous Objects by Kokichi Sugihara 

From Amazon (Japan): BUY NOW set of four ambiguous objects with booklet 
This kit contains four white plastic illusion objects (including the arrow) and a booklet. I used the translate feature in the Chrome browser to place my order and it shipped to California in a few days. 

The math and physics are described here in this technical journal article by Prof. Sugihara

Ambiguous Object Illusion Mug: circle or a square? It’s all a matter of perspective and viewing angle. The complex shape allows for both to be perceived and is based on the work of mathematician Kokichi Sugihara of Meiji University in Japan, the inventor of this illusion and art form. 

Centripetal Egg

This bird-in-egg and similar vintage style tin toys avalable here:

From eBay: BUY NOW: Centripetal Egg Tin Toy

From Etsy: BUY NOW: Centripetal Egg Tin Toy

Centripetal Egg: a simple rack and pinion mechanism spins up the tin egg shell to reveal a duckling in this vintage style tin toy. The four pieces of the egg shell are held in place with a rubber band. With sufficient centripetal acceleration the elastic force of the rubber band is temporarily overcome until the spinning assembly slows down and the egg snaps shut again. 


Split Sphere Spin Top

Available here:

From Grand Illusions LTD: BUY NOW: Naef Spin

Split Sphere Spin Top: this finely crafted wooden top spins in a stable fashion as long as it does not tilt from the vertical more than a few degrees. If the top does lean over centripetal acceleration will pull the halves apart which then roll in a circle due to conservation of angular momentum. The second video shows the process in slow motion. A simple and elegant design by Keira Seto sold by Swiss toy manufacturer Naef.

Magneview Flim

Get some magnetic viewing film here: 
From Educational Innovations: BUY NOW Magnetic Viewing Film 

Magneview Flim: making the invisible visible and revealing the hidden physics of our everyday world. Microscopic cavities in this green film are filled with oil and tiny flakes of Nickel metal- like compass needles, the flakes align with the magnetic fields revealing the complexity of the north and south pole domains of these magnets. Two of the disk magnets have multiple north and south poles and look like gears with teeth- these are rotors from small motors. 

Homopolar Motor

Fairly simple to make- here are the inexpensive supplies needed to make a few of these motors. 
AA batteries have a diameter of 14.5 mm, so a bottom magnet with a diameter of 15 mm is just right: 
From eBay: BUY NOW Neodymium Disk Magnet 

Wire that looks and works well is just 10 gauge ground wire. Inexpensive and available at any local hardware store-- or order a small quantity here: 
From eBay: BUY NOW 10 gauge Copper Wire 

Wikipedia has some good details on the physics of homopolar motors 

Homopolar Motor: a minimalist electric motor- battery, wire, and magnet. This type of motor does not need a commutator- the polarity of the electromagnetic coil does not need to reverse. The challenge with this design is balancing the coil to center on the battery as it rotates. A favorite DIY physics toy!