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Poly Density Puzzle

Get the kit here: 
From Educational Innovations: BUY NOW Polydensity Bottle Kit 

Folow the link above for details of the physics explanation. 

Poly Density Puzzle: my favorite science brain teaser- white beads and blue beads "float" oddly separated beneath the surface of a clear liquid. If the contents are mixed by shaking the container, the white beads gather at the top and the blue sink to bottom! Adding to the mystery; after about 30 seconds the two layers of beads will have slowly moved back to the middle. What is your guess as to the physics behind this behavior?

Mirascope

Similar devices available here:
From Educational Innovations: BUY NOW Mirascope 
From Amazon: BUY NOW Mirascope 
 

Mirascope: two parabolic mirrors create a 3D image above the actual object. A repost of one of my favorite physics toys ever. The image of the dice made here is not a hologram and is produced solely by reflection of light rays between special concave mirrors. Discovered circa 1969 by Landry and Elings at UC Santa Barbara.

Aristotle's Wheel Paradox 

Get this demonstration puzzle here:

From Etsy: BUY NOW: Aristotle's Wheel

WIkipedia has some details on the Wheel "Paradox"

Aristotle’s Wheel “Paradox”: How does the smaller attached disk travel the same length as the larger one if both disks only make one full rotation? Note the shorter path of the smaller disk, if rolled on its own. This beautifully made demonstration depicts an issue of geometry and motion that perplexed the best minds of humanity for 2000 years. The ancients knew the formula for circumference, and C=2πR for the large disk is clearly greater than C=2πr for the smaller- so how could the smaller disk, rotated once, still travel the distance of the larger one if attached? The great Galileo even offered a solution to the problem in his book Two New Sciences, where he approximated the situation as concentric hexagons and considered the limit as the number of sides increased. So what is the best answer to make sense of this situation?


In-Feed Google 3

Satisfying Hexagons

Get this 3D print here (your choice of colors):

From Etsy: BUY NOW: Satifying Hexagons

Satisfying Hexagons: this delightful kinetic art manipulation toy features 19 nested hexagons within a hexagonal frame. Embedded magnets allows one to move the central hexagon from behind creating interesting visual effects. A 3D print created by @i.am.the.lazy.engineer- indeed oddly satisfying!


Vibration Unthreading

Get inexpensive small motors and accesories for DIY projects here:
From Amazon: BUY NOW DC Motors Kit

A DIY project to see if just shaking a bolt at the right frequency could make a standard nut rotate and fall off. Similar physics to the phase locking propeller toy featured in my last post. Motivated by videos seen on Instagram where a brass bolt is placed in magnetic putty and the nut mysteriously rotates up and off- now convinced that vibration is how that effect is produced. Here a small DC motor spins an offset mass to produce the vibrations.

Impossible Arrow

One of many creative illusions and curiosities of Victoria Skye. See her work here:

Visit Now: Victoria's Illusion Art

Click here for to explore more "impossible objects" 

Impossible Arrow: an arrow made of wood through the center of standard steel hex nut. The arrow was carved and somehow placed through the nut- neither the wood nor the steel nut was cut or glued to produce this object. Not impossible, but creating this does depend on the use of some obscure physical properties of wood (similar to the impossible nail sculpture). 

Aquarius Fountain Lamp

These fountains are individually made by the artist hence they are priced as art reflecting the labor involved: 
From Etsy store of Stephen Co : BUY NOW 
Aquarius Fountain Lamp

Aquarius Fountain Lamp: an oscillating stream of water is illuminated by strobe lights to reveal underlying structures and forms typically hidden from our vision. With the help of programmable micro-controllers, strips of addressable RBG LEDs are made to flash in sequences that make the water stream appear to move upwards, change colors, and split into multiple braided streams. Art meets physics and clever technology in this wonderful creation by computer engineer Stephen Co. With sincere appreciation to Stephen @northerncircuits for sending me one of his hand crafted high tech fountains.


Time's Up

Similar timers available from these sources: 
From eBay: BUY NOW 
Inverted Timer 


From Amazon: BUY NOW 
Inverted Timer 


Time's Up: inverse of the sandglass- tiny plastic beads are less dense than the water and thus ascend to the top of the container under the influence of a buoyant force in accordance with Archimedes' principle. This timer takes almost exactly 6 minutes to complete shown here at normal speed for the first half of this video, and the second half is condensed to 24 seconds in time-lapse. 

The Swinging Sticks

The Swinging Sticks Desktop Toy version from their website: 
From GeelongShop.com: BUY NOW The Swinging Sticks
 

The Swinging Sticks: a driven coupled chaotic physical pendulum as kinetic art where the placement of the rods' axes of rotation are engineered to exhibit the widest range of interesting motion. Four AA batteries and a simple electromagnetic kicker circuit in the base gives a tiny push to a magnet in the end of the large rod, keeping the system in motion for over a year! Perhaps one of the most famous physics toys out there as it was featured in the movie Iron Man II (sitting on the desk of Pepper Potts).



Maxwell's Dynamical Top: Historical Replica

Get this accurate and beautiful 1/2 scale replica here:

From Machined Marvels: BUY NOW: Maxwell's Dynamical Top

Maxwell’s Dynamical Top: one of my favorite demonstrations of the strange properties of rotating bodies- shown here with a 1/2 scale but exacting replica (@machinedmarvels) of the famous “Dynamical Top” created and demonstrated by the great physicist James Clerk Maxwell in 1857. When this brass bell shaped top is spinning an interesting stability can occur- push on the pointed stem and the top will push back, forcing the stem against that object, and friction will cause the stem to roll along and trace the edge of the object. Note- magnets are NOT involved here. The key to this design is to make the contact point/tip of the top at its own center of mass, then any frictional force in contact with the stem will produce a torque about the contact point at a right angle to the direction of friction that creates the stabilizing force (students of physics may recognize application of the right hand rule here). This beautiful historical replica is now available from machinist and creator Jim Peever @machinedmarvels- and as far as I know the only other replicas of this device where made in the 1880’s!

Maxwell's Dynamical Top: with Color Wheel

Get this accurate and beautiful 1/2 scale replica here:

From Machined Marvels: BUY NOW: Maxwell's Dynamical Top

Maxwell’s Dynamical Top: A 1/2 scale precision replica of the famous “Dynamical Top” created and demonstrated by the great physicist James Clerk Maxwell in 1857. The four color disk allowed Maxwell to see and study the direction of the angular momentum vector when a spinning object is subjected to a jolt/impact. After the top gets a flick from my hand note that one can see a circle of evenly changing color- the angular momentum vector points outward through the center of that circle. Balanced such that the spin point was placed at its center of mass, this unique top was used by Maxwell to experimentally test many theories about how the Earth and planets wobble as they spin. Swipe to see another astonishing property of this top described in a previous post. This beautiful historical replica is now available from machinist and creator Jim Peever @machinedmarvels- and as far as I know the only other replicas of this device where made in the 1880’s!