Budget physics

Pop Pop Boat

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

Note: this site contains affiliate links for which I may be compensated

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.

Strandbeest Mini

Get one here! Make sure to get the Jr. Scientist version of this kit for best results. 
From Amazon: BUY NOW Strandbeest Model Kit 

Read about Theo Jansen and his novel leg linkage mechanism for the Strandbeests via these Wiki pages.

Note: this site contains affiliate links for which I may be compensated 

Strandbeest Mini: A fully working model of artist Theo Jansen's Strandbeest kinetic sculpture which features Jansen's linkage- a unique leg mechanism which converts rotary motion of a crackshaft into smooth walking motion. Jansen's creations are usually a couple meters high and walk the beaches of the Netherlands powered by the wind. This version comes as a model kit that snaps together with no glue- a really fun project!


Poly acrylamide Polymer Vanishing Act

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

Note: this site contains affiliate links for which I may be compensated

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! 

Precession of a Gyroscope

Get one here: 
From Amazon: BUY NOW Gyroscopes 

Note: this site contains affiliate links for which I may be compensated

Precession of a Gyroscope: in defiance of gravity this gyroscope is supported only at one end. The physics and vector nature of angular momentum! Note that as friction slows the rotor of the gyroscope down, the precession rotation rate gets faster and faster. After some energy loss the gyroscope contacts the table and vibrations move the unit around while the angular momentum maintains its orientation. 

Thermochromic Liquid Crystal Mood Necklace

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

Note: this site contains affiliate links for which I may be compensated

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. 


Top Secret

This physics toy top is available here: 

From Amazon: BUY NOW Mystery Spinning Top

Note: this site contains affiliate links for which I may be compensated 


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.

Acrylic Rattleback

These acrylic versions work great and are inexpensive: 
From Educational Innovations: BUY NOW Rattlebacks 
From Amazon: BUY NOW Rattlebacks 

Note: this site contains affiliate links for which I may be compensated

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


Magnetic Levitation in 1D

Get one from these fine sources: 
From Educational Innovations: BUY NOW Floating Ring Magnet Set 
From Amazon: BUY NOW Floating Ring Magnet Set 

Note: this site contains affiliate links for which I may be compensated

Magnetic Levitation in 1D: a stack of dipole magnets. Note how the spacing between any two magnets is proportional to weight of how many magnets there are above the gap. Gravity vs Magnetism. 

Reaction Rocket

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

Note: this site contains affiliate links for which I may be compensated

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).

Magnetic Sand Hourglass

Get one from these fine sources: 
From Amazon: BUY NOW Magnetic Hourglass 

Note: this site contains affiliate links for which I may be compensated

Magnetic Sand Hourglass: ferromagnetic sand collects above a neodymium magnet in the wood base. Each particulate of ferromagnetic iron becomes a temporary dipole magnet in the presence of the magnetic field in the base. The tiny dipoles link up north ends to south ends, creating interesting patterns that reveal the magnetic field lines. 


Oil Drop Timer

Get one here: 
From Amazon: BUY NOW Dolphin Timer 

Note: this site contains affiliate links for which I may be compensated

Oil Drop Timer with Dolphins: immiscible fluids of different densities stay separate under gravity with the lightest density on top. The density of the plastic dolphins is greater than the density of the top fluid but less than the density of the bottom fluid, so they stay at the boundary in equilibrium. The dolphins have a metal weight in their tails so that the buoyant force will keep them upright even as the liquids trade places (2 minutes shown in time-lapse). Archimedes' Principal at work here at multiple levels. 

Self-Propelled Homopolar Motor on Aluminum Foil Racetrack

I used neodymium disk magnets, small end = 1/2" diameter, Large end = 3/4" diameter. 
From Amazon: BUY NOW Disk Magnets for Simple Motor

Note: this site contains affiliate links for which I may be compensated

Foil Runner Motor assembly diagram: 
Self-Propelled Homopolar Motor on Aluminum Foil Racetrack: A favorite DIY physics toy where disk shaped neodymium magnets supply the static magnetic field for this motor and become the wheels of a very simple vehicle with an AAA battery as the energy source. As soon as both ends make contact with the conducting aluminium foil an electric current will flow which in turn induces a magnetic field underneath the battery assembly. This induced field will then interact with the neodymium magnets on each end causing them to spin- a wonderful example of a motor with minimal components. The racetrack is a cardboard circle from a pizza box covered in kitchen foil.


Oil Drop Cascade

Avilable here: 
From Amazon: BUY NOW Oil Drop Cascade Timer

Note: this site contains affiliate links for which I may be compensated

Oil Drop Cascade: interplay of surface tension and gravity bend oil drops into strange shapes as they move through a grid of obstacles in this kinetic art toy. Like other oil drop timer toys, the colored oil will not mix with the clear kerosene liquid. 

TrueBalance

Get the full version (8 disks made of wood) or the mini (6 disks, blue or red plastic): 
From Amazon: BUY NOW TrueBalance Coordination Puzzle 

Note: this site contains affiliate links for which I may be compensated

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! 

Pixelated Playing Cards

Available from these fine sources: 
From Amazon: BUY NOW Pixel Cards 

Note: this site contains affiliate links for which I may be compensated

Pixelated Playing Cards: what one sees is all about the lighting with this transparent deck of cards. When backlit these poker sized cards become simply a grid of dots- reminding us that what we see not only concerns the physical properties of the perceived object, but also the location of the light source and the frequency and intensity of its emissions.