Budget physics

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!

Switch Pitch Ball

Get one here: 

From Edicational Innovations: BUY NOW: Switch Pitch Ball

Switch Pitch Ball: this spherical assembly changes color by turning inside out when tossed into the air. A favorite of my mechanical toys with surprising physics. Interestingly the advertisements for this toy incorrectly claim air drag is involved in the transformation. To understand why the ball inverts first note that the ball is made of multiple components hinged together. In launching the ball from the hand an upward acceleration results in a torque that pivots each component around its center of mass, causing the rotation of these components in an organized way leading to the transformation. Imagine tossing a stick straight up. If the stick is perfectly vertical upon launch it will move straight up- but if it is initially slanted at all it will also begin to rotate upon launch. Similar physics underlies the motion of each component of the ball- shown here in 240 fps slow motion. The Switch Pitch is produced by the makers of the Hoberman Sphere. 


Newtons Yo-Yo

Get a set here: 
From Educational Innovations: BUY NOW Newton's Yoyo 
 

Newton Yo Yo: Newton's 3rd Law states that action force equals opposite reaction force- the the green and yellow spheres have equal mass, so the forces of the collision provide accelerations that are equal and opposite such that the spheres trade places.

Thermochromic Liquid Crystal Mood Necklace

Similar mood jewelry available here: 
From Etsy: BUY NOW Liquid crystal jewelry 

Thermochromic Liquid Crystal “Mood” Necklace: heat from a hand brings out the temperature dependent color change of the liquid crystal. The molecules of the liquid crystal change orientation and spacing during the phase transition from liquid (warm) to crystal (cool). The molecular configuration shift allows for different diffraction effects producing the color shift. 

Acrylic Rattleback

These acrylic versions work great and are inexpensive: 

From STEMCell Science: 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


Pop Pop Boat

Get one here: 
From Educational Innovations: BUY NOW Pop-Pop Boat 
From Amazon: BUY NOW Pop-Pop Boats 

Wikipedia has the details on the physics and history of this little steamboat toy 

Pop-Pop Boat: birthday candle powered, super simple steam engine named after the sound it makes when operating. The engine is just a metal box, heated by the candle, with two pipes coming out of it. Steam builds up pushing water out with an explosive pop- which then creates a vacuum sucking more water in to repeat the process. Patented in 1915 these were very popular in the 1940's.

Top Secret

This physics toy top is available here: 

From Amazon: BUY NOW Mystery Spinning Top

From eBay: BUY NOW Mystery Spinning Top 


The amazing green magnetic viewing film is also available: 
From Educational Innovations: BUY NOW Magnetic Field Viewing Film 

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.


Mini-Lollipopter

Available here:

From Amazon: BUY NOW: Lollipopter Kinetics

From eBay: BUY NOW: Lollipopter Kinetics

Mini-Lollipopter: new smaller cousin of one of my favorite interactive kinetic sculpture designs. A snap of the wrist imparts angular momentum to the "petals" which then rotate until an internal mechanism stops their motion with predetermined spacing- clockwise rotation transforms a helix to an abstract pine cone, counterclockwise returns the helix. Created by @john.edmark.

Scale Solar System Sticker Set

Get this fantastic set here:
From TheCuriosityBox: BUY NOW: Scale Solar System

This set came in my Curiosity Box subscrition. A great way to start collecting your own physics toys (and other brain food):
From the Vsauce team: BUY NOW: The Curiosity Box

Scale Solar System Sticker Set: one of the most amazing facts about the planets in our solar system is their relative sizes. Finally! a set of stickers- made to scale- using images from NASA, brought to you by the Vsauce team @thecuriositybox. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and dwarf planet Pluto included for comparison- all in their current order (sometimes Pluto is closer than Neptune), and mounted here on a sheet of polycarbonate.

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.


Reaction Rocket

The essence of a great physics toy: simple inexpensive design showing complex physics 
From Educational Innovations: BUY NOW Reaction Rocket 

Reaction Rocket: projectile launch via momentum transfer in slow motion. The superball/straw base bounces off the table top and then immediately collides with the bottom of the rocket sending it off with a velocity slightly less than 3 times the velocity of the rising ball (true if the ball is more than three times the mass of the rocket). Newton's third law in action! Note that the rocket rises much higher than the drop height (up to 9 times higher).

Photochromic Frisbee

Get this quality flying disk here:

From Amazon: BUY NOW: UV Chameleon by Discraft

You may also want a powerful UV flashlight:
From Amazon: BUY NOW: High Power UV Light

Photochromic Frisbee: the plastic of the UV Chameleon by Discraft contains photochromic pigment molecules that actually change shape when struck by photons of UV light, and the new shape alters their absorption properties such that they reflect a deep purple color. The color is temporary- room temperature thermal energy bumps the molecules back into their original configuration, and the color fades back to white in about 3 minutes (shown here sped up x7). A long wave UV flashlight is used to “paint” the disk purple, and sunlight will do the same very quickly.

Mini Wind Turbine

Nice little unit for the price! 
From eBay: BUY NOW Mini Wind Turbine 
From Amazon: BUY NOW Mini Wind Turbine 

Mini Wind Turbine: self-contained miniature horizontal axis wind turbine generates enough power to light three LEDs. A small turbine blade is attached to the rotor of a tiny generator that powers the LEDs. Conversion of energy- wind kinetic energy to rotational kinetic energy to electrical energy to light energy. I like how the wind vane and tower are also designed from acrylic as light pipes for the LED light. A fun little toy that demonstrates the physics of renewable energy!


Poly acrylamide Polymer Vanishing Act

Get some of these grow-spheres here: 
From Educational Innovations: BUY NOW Growing Spheres 

Poly-acrylamide Polymer Vanishing Act: these spheres of hydrophilic polymer have an almost identical index of refraction as that of water- thus when submersed they become invisible. Note the elasticity of these spheres from the way they bounce, while at the same time they refract their surroundings as a spherical lens. The super absorbent spheres start as hard crystals with a radius of 2mm and grow to 11mm when immersed in water. So much physics going on here! 

Drinking Bird Heat Engine

Get this famous physics toy 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
Drinking Bird Heat Engine: time lapse of 15 minutes into 15 seconds (4 cycles). Cooling by evaporation at the head leads to lower pressure in the top bulb, the dichloromethane fluid rises 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 time lapse allows a clearer picture of how the fluid rises, shifting the center of mass, and how tipping makes the glass column lift out of the fluid in the bottom allowing the pressure to equalize and letting gravity pull the fluid to return to the base. Process repeats as long as the top stays wet. So much physics in one hypnotic toy!