### Newton's Spindle

This unique toy only available here:

From safetynailer.com:** BUY NOW: Newton's Spindle**

Follow this link for a regular **Newton's Yo-Yo**

Newton's Spindle: the latest innovation- a quite clacker (lol!) which uses neodymium magnets as the swinging weights. The weights still collide but without making physical contact via magnetic repulsion, yet the exchange of momentum is just like that of a regular Newton’s yo-yo. Newton's 3rd Law states that action force equals opposite reaction force- here the red and blue weights (embedded magnets) are equal in mass, so the forces of each collision provide accelerations that are equal and opposite such that the deceleration of the incoming sphere is equal to the acceleration of the outgoing sphere and the spheres trade places leaving one always at rest.

### Nixie Tube Clock

The Nixie Tube Clock in the video is of amazing craftsmanship- real hardwood with brass accents and solid construction. Get one from this excellent shop:

From Etsy:** BUY NOW **

Nixie Tube Clocks

Nixie Tube Clock: long before there were 7 segment LED displays there was the Nixie- cold cathode tubes with a wire mesh and 10 cathodes shaped in the form of numerals 0-9 that illuminate through neon glow discharge. The “Numeric Indicator eXperimental 1” or NIX 1 was introduced in 1955 by Burroughs Corporation and manufactured until the 1990s. This clock uses modern electronics to power Russian versions called the ИH-19A where the numbers are stacked so the front symbols obscure each lighted cathode minimally: from back to front 1320984756.

### Andrew's Space Wheel

This vintage 1970s item available now on eBay

From eBay:** BUY NOW Andrews Space Wheel **

Andrew's Space Wheel: kinetic art desk toy from the 70s- the rotor will stay in motion for weeks, until the hidden 9V battery is depleted. The rotor has a magnet at the end of each spoke- a coil and circuit identical to that of the "Top Secret" mystery top that I've posted about gives these magnets a push as the rotor passes through the middle- conservation of energy and angular momentum does the rest!

### RPSLK Dice

These dice are available here:

From Amazon: **BUY NOW: Rock Paper Scissors Lizard Spock Dice**

RPSLK Dice: the famous Lizard Spock extension to the Rock, Paper, Scissors game expressed on 10 sided dice allowing the study of the non-associative nature of the game (Rock wins Scissors, and Scissors wins Paper, but Rock does not win Paper, etc.), and other interesting math. The original RPS game had three “weapons” and only three rules are needed to play the game. Adding Lizard-Spock makes for 5 gestures, but now 10 rules must be used, including “Spock vaporizes Rock”, “Lizard poisons Spock”, and my favorite “Paper disproves Spock” (swipe to see famous graphic). Interestingly, mathematical analysis shows a similar four weapon game with equal odds of winning is not possible. It was also found that the next possible game with 7 gestures would require 21 rules to play. The Lizard-Spock extension was invented by Sam Kass and Karen Bryla in 2005 and made famous on the sitcom Big Bang Theory.

### Holiday Pyramid

Many types and themes available:

From Amazon: **BUY NOW Christmas Pyramids **

From eBay: **BUY NOW Christmas Pyramid**

Holiday Pyramid: a simple heat engine- rotational motion resulting from the convection of hot air due to the candle flames of two tea lights. These holiday decorations come from a German Christmas tradition, Weihnachtspyramide, that dates back more than 200 years! Energy transfer: chemical bonds to heat to kinetic energy of the rising air to rotational kinetic energy of the turbine and reindeer.

### The Lollipopter

Many styles/colors 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.

### Spinning Snowflakes Convection Candle

Get this convection candle here:

From Amazon: **BUY NOW Spinning Kinetic Candles **

Other convection turbines here on eBay:

From eBay: **BUY NOW Spinning Convection Candles **

Spinning Snowflakes Convection Candle: with chimney effect! This holiday candle is a simple turbine heat engine where rotational motion results from the convection of hot air from the candle flame of a tea light, which is also surrounded by a glass cylinder which enhances the convective flow via the chimney effect. A quick investigation finds the rotor spins twice as fast with the glass cylinder in place. All moving parts of thin stainless steel with some assembly required. Energy transfer: chemical bonds- to heat- to kinetic energy of the rising air- to rotational kinetic energy of the turbine and snowflakes.

### Glass Spirals Kinetic Ornament

Sometime available from these sources:

From Etsy: **BUY NOW: Glass Spiral Ornaments **

Glass Spirals Kinetic Ornament: a thread of glass is shaped into connected helixes in this holiday decoration- one clockwise the other counterclockwise. When spinning the rotational motion creates translational motion both upwards and downwards along the vertical direction. Mesmerizing holiday decor!

### Oscilating Cylinder Steam Engine

Get this tiny working engine here: (brass and stainless steel)

From engineDIY: **BUY NOW: Tiny Steam Engine**

Two other similar mini-engines to consider: **BUY NOW: Mini-Steam 1, Mini-Steam 2 **

Oscillating Cylinder Steam Engine: a functional “wobbler” type piston steam engine complete with boiler and flywheel. In this design the cylinder and piston both rock back and forth, acting as the valve mechanism to allow the hot steam to enter through a small hole, and then exit on the next stroke out through the tiny exhaust port in the top. Takes about 4 minutes to get going after the lamp is lit. A tiny version of the invention that powered the industrial revolution.

### Sphere Sticks Geometric Puzzle

Get this affordable and amazing puzzle here:

From Etsy: **BUY NOW: Sphere Sticks**

Sphere Sticks Puzzle: 30 identical wood pieces, each with two notches as shown, can create 12 interlocking pentagons in a perfect symmetry- look carefully and you can see that each rod is in an identical configuration with the 4 others that connect with it. Precision cut notches on the rods allow them to interlock with elastic tension such that vector sum of the 4 forces sum to zero in this tensegrity type equilibrium. The dodecahedron, with its 30 edges and 12 sides, is the basis of this puzzle sculpture.

### The Physics of Tippe-Top Inversion

Get a nice tippe-top from this fine source:

From Art of Play: **BUY NOW Flip Over Tops**

The Physics of Tippe-Top Inversion: spinning things often have surprising physics! From a talk I gave about this time last year at PhysicsCon 2020 held in Caltech’s Feynman Lecture Hall where I described the physics behind flip-over tops and other physics toys. In brief: friction with the surface provides a torque that acts on the existing angular momentum of the top to flip it over. The top will stay flipped until the spin rate slows down enough to where its center of mass pulls it back to the resting position. Inversion phase shown at 240fps- note the little hop the top takes as it goes on to its stem!

### Rhombic Blocks Mathematical Puzzle

This beautifully made puzzle available here::

From Etsy: **BUY NOW **

Rhombic Blocks

Rhombic Blocks Mathematical Puzzle: There are 9 possible ways three rhombuses can be joined together along a common edge, and similar to pentominoes, these 9 tri-rhombs can tile a polyhedron, in this case a hexagon. There are 14 solutions to this puzzle, and one where no same-colored pieces touch. A beautiful math discovery by puzzle master Stuart Coffin.

### Static Spheres

Get this inexpensive device here:

From Educational Innovations: **BUY NOW: Static Spheres**

Click here for other static electricity devices

Static Spheres: triboelectric effect toy. The red acetate spheres are given an acquired net negative charge, and their mutual repulsion allows them to jump a centimeter or more as charge is manipulated on the PET plastic container. Bringing an object near the container momentarily moves electrons (charge) around creating repulsive forces (sphere v. sphere) and attractive forces (spheres and container) resulting in the observed motions. The red spheres interact with each other without coming into physical contact (as shown in 240 fps slow motion) as like charges repel. Shaking the system a bit allows the red spheres to pick up charge in the first place by colliding with the container.

### 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.

### Arch Balance Toy

Get this elegant toy here:

From Ludu Ludi in Spain: **Nivana Balance Toy**

Arch Balance Toy: this elegant sculpture toy seemingly defies gravity- a careful placement of the pendulum will locate the center of mass of the arch + pendulum system directly above the 1cm wide foot of the arch, creating a state of unstable equilibrium. No magnets used or needed for this physics! Hang and balance your favorite object from this arch. Made in Spain by Pico Pao, the Nirvana balance toy come with an old fashioned throwing top as the pendulum bob.

### Centripetal Kinetic Toy

This "iBall" desk toy is no longer in producltion. Howerver, a similar version of this toy can be made from these components:

From Amazon: **BUY NOW: two piece acrylic shell**

From Amazon: **BUY NOW: 1/4 inch ball bearings**

Centripetal Kinetic Toy: seven rolling steel balls hug to the inside of the acrylic sphere given sufficient velocity. Here the balls are launched such that their orbits are in the same plane, and due to their angular momentum (and a torque due to gravity) the plane of rotation precesses like the axis of a spinning top until friction slows them down. This toy was made in 2007 (sadly no longer in production) and marketed under the name "iBall".

### Reuleaux Rotor

This toy is availble from Amazon Japan and will ship to the US:

From Amazon.jp: **BUY NOW: Reuleaux Rotor Wodden Toy**

Reuleaux Rotor: this famous curve of constant width, the Reuleaux triangle, can rotate such that at all times it remains in contact with all four sides of a square. As demonstrated by this wooden toy from Japan, the rotor covers approximately 98.77% of the area of the square, missing only the sharp corners. The curves in the corners are in the shape of an elliptical arc. Fun fact: a Reuleaux triangle has a perimeter equal to pi times its width- just like a circle!

### 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 **

Other interesting engines available here:** Simple Heat Engines**

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.