All physicsfun toys

Rolling Ball Fountain

Find this and similar fountains here:

From Amazon: BUY NOW: Rolling Ball Fountain

Rolling Ball Fountain: this miniature kugel fountain features a glass sphere that sits on a socket of precisely similar shape, and is suspended on a very thin (less than half a mm) film of moving water which greatly reduces friction. The velocity of the water in the thin layer slows as it spreads out via a hole in the socket, and this hole is offset from the center so that the interaction with the water stream sets the ball spinning. A small pump provides the flow rate, and colorful LEDs illuminate the glass sphere to show off the rotation. Perhaps you’ve seen public art installations featuring giant granite spheres weighing tons and yet similarly suspended on a thin layer of flowing water. Physics principles involved here include viscosity and Reynold’s number, the Navier-Stokes equation, Bernoulli’s principle and the study of thin layer lubricants.

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Top Secret

This physics toy top is available here: 
From Amazon: BUY NOW Mystery Spinning Top 

Here is the 1974 patent showing the very simple circuit of this device. The spinning dipole (the top itself) induces a current in one of the coils, and this current is fed to the base of the transistor turning the electromagnet on when the top is near. 
 

"Top Secret": this top will stay spinning for more than a week- because it is actually a motor! The top is a dipole magnet (as revealed by Magneview film) and the base has an electromagnet that gives the dipole a push when the top comes near the center. An ingeniously simple circuit consisting of only a battery, a coil, and a transistor, is activated when the spinning magnet nears the coil turning on the electromagnet to give a boost to the spin of the magnetic top.

Acrylic Rattleback

These acrylic versions work great and are inexpensive: 

From Amazon: BUY NOW: Rattlebacks 

Acrylic Rattleback: a favorite from my collection- 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 the asymmetric shape of the bottom of this kind of rattleback, it's somewhat propeller shaped with an "S" curve along the bottom ridge

The Lollipopter

Four styles to choose from: 
From Amazon: BUY NOW: Lollipopter Kinetic Art 

The Lollipopter (The Helicone): one of my favorite interactive kinetic sculpture designs. With a bit of practice one can master the transformation in both directions: A snap of the wrist imparts angular momentum to the "petals" which then rotate until an internal mechanism stops their motion with predetermined spacing- a helix transforms to an abstract pine cone. A second snap of the wrist in the opposite direction returns the helix. A creation by artist John Edmark. 


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Spinning Liquid Paperweight

Many versions available here 
From Amazon: BUY NOW Liquid Wave Paperweight Toy 

Spinning Liquid Paperweight: two immiscible liquids (three if you count the air bubble) are sorted under gravity by density with the densest on the bottom and the lightest on top. If the container is rotated the boundary between the layers forms a parabola due to the added influence of centripetal acceleration. As seen here in 240 fps slow motion, symmetric waves travel and reflect along the curved surface for the first few rotations until damped out via viscosity and friction. The plastic fish have a density between that of the two liquids so they stay at the boundary layer. 

Well Balanced Cabernet

Similar wine racks available here: 
From Amazon: BUY NOW 
Balance Wine Rack 

Well Balanced Cabernet: a carefully engineered acrylic version of this famous demonstration- the center of mass of the rack/wine bottle system is directly over the base providing unstable equilibrium for this balancing act. Suspended here is Hypothesis by Roots Run Deep, an excellent Napa cabernet sauvignon. 


Slinky Treadmill

From AMAZON : Scientific Slinky

Learn more about the physics of the slinky here: Exploratorium Science Snack 
The slinky has been a popular toy since 1945! Read about the history and physics of the slinky, and the naval mechanical engineer that invented it on Wikipedia
Visit the Exploratorium 

Slinky Treadmill by @exploratorium: kinetic motion energy transfers to elastic potential energy and then back to kinetic energy in a cycling process as a slinky spring "walks" down an incline. Put the system on a treadmill, such as this one at the Exploratorium in San Francisco, and the walking behavior can be explored for many minutes. Note that after a while the slinky's walking becomes erratic.? With special thanks to the Exploratorium!

TrueBalance

From Amazon: BUY NOW TrueBalance Coordination Puzzle 

TrueBalance: coordination challenge puzzle- get the six disks, connected by bearing swivels, into a vertical stack by only tilting the handle. Harder than it looks to get each disk’s center of mass above the one below at the same time into the unstable equilibrium final state. The swivels constrain the system, limiting the degrees of freedom, and allowing strange and interesting motion. Kinetic art as a toy! 


Disappearing Spoon

Gallimum metal and a silicone mold to produce the spoon- available here:

From Amazon: BUY NOW: Gallium Mold Spoon Kit 

Disappearing Spoon: the metal gallium has a melting point of 30°C (86°F) and will melt quickly when exposed to tea temperature hot water- or melt in one’s hand if handled too long. This spoon was made with a silicone mold (swipe to see process), and feels and sounds just like a regular spoon, except solid gallium is brittle and the spoon can shatter like glass if dropped. An amazing parlor trick as well as a classic and historical class demonstration.

Euler's Disk

Get one here: 
From Amazon: BUY NOW Euler's Disk 

Wikipedia has an excellent introduction to the physics of Euler's Disk 

Eulers Disk: (best with sound on) this toy exhibits the motion of a “sprolling” coin, a motion that combines spinning and rolling. Designed with a large mass and very smooth edge, this device takes close to 3 minutes to come to rest- and amazingly, the contact point between the disk and the mirror can reach a speed of more that 200 mph! This video catches the first and last parts of this 2 minute and 42 second run, with two cuts to 240fps slow motion to show the curious motion. Watch the end with the sound on! 


Zoetrope

Get this inexpensive version here- comes with many animations and balnk strips tomake your own:

From Amazon: BUY NOW: Zoetrope 

Zoetrope: the physics and psychophysics of motion animation- still images flashed in rapid succession produces the illusion of motion through persistence of vision. The slits are crucial to creating the illusion by blacking out the visual stimulus for a short duration- without these pauses only a blur is perceived. When the image flash rate is above the flicker fusion frequency (approximately 16Hz) we perceive fluid motion- the basis for all movies and TV. 

Hyperbolic Holes

This inexpensive kit available here: From Amazon : BUY NOW
Hyperbolic Holes Kit

Hyperbolic Holes: a straight rod, in this case a pencil, glides through a symmetrical pair of curved holes. The design is based on the hyperboloid, the 3D ruled surface traced by an offset rotating diagonal line. This device is sold as an inexpensive kit to assemble yourself, and includes a motor with geared drive and pre-cut pieces. The pencil is my addition- just the right size to clear the curved openings.