Budget physics

Hydrophobic Water Maze

Wonderfully well crafted and available from this shop :
From Etsy store TheSmallestWorkshop:

BUY NOW Hydrophobic Water Maze

Hydrophobic Water Maze: a superhydrophobic coating allows this dynamic puzzle to use a drop of water as the "pinball", which can split into multiple smaller drops and recombine along the way. The wood surface is treated with silica nano-coating that makes water roll off- a condition sometimes referred to as the Lotus effect because leaves of the Lotus plant have this property.

Polarization Test Card

These inexpensive test cards are available here: 
From eBay: BUY NOW 
Polarization Test Cards 


Get some polarizing filter sheets here: 
From Amazon: BUY NOW Polarizing Sheets 

Explore many aspects of polarization with this kit: 
From Educational Innovations: BUY NOW Polarizing Filter Demo Kit 

See this short introduction to linear polarizing filters on Hyperphysics, and many more details on polarization from Wikipedia

Polarization Test Card: light has features that are invisible to the human eye, such as the orientation of its electric field (denoted as polarization), but can be revealed to us by a polarizing filter, used to block light with specific polarization orientations. Inexpensive test cards like this are often found in shops selling polarized sunglasses. The molecular structure of plastics can rotate the polarization of any light that passes through, and this card has such thin layers added to the top of the photo to create the hidden silhouettes seen here. 

 

MaBoRun Minis

Many styles to choose from- get a MaBoRun here: 

From eBay: BUY NOW: MaBoRun Mini

Similar devices here:
From Amazon: BUY NOW MaBoRun Marble Run 

MaBoRun Minis: rolling marbles doing tricks as gravitational potential energy is converted to kinetic energy. Three mini marble runs each with a battery powered means of lifting the marbles: 1) a belt driven gear, 2) a scissor linkage that translates the rotation of the motor into linear motion to lift the marbles to the top and 3) an Archimedean Screw conveyer. Two of these runs incorporate a simulation of decaying orbits with conservation of angular momentum as the marbles whirl down funnel shaped tracks.


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.

Floating Yen

These aluminium 1 Yen coins are the perfect denisty to float as shown in the video:

From Etsy: BUY NOW: 1-Yen Coins (20)

Floating Yen: the surface tension of water is strong enough to suspend the aluminum coin, and a trapped column of air in a second glass can submerge a portion of the surface with the coin. The 1-Yen coin has just the right mass and density for this demonstration. One of my favorite DIY physics demonstrations.

Van de Graaff Generator

This device is sold as the "Static Shocker" hands on lab. Get one here for $8.95! : 
From Educational Innovations: BUY NOW Static Shocker Mini Van de Graaff 

The device can use an empty aluminum can for the top electrode which works- but this $9 hollow steel sphere looks and works even better- I used the 80mm sphere: 
From eBay: BUY NOW Hollow Steel Sphere 

Van de Graaff Generator: this miniature electrostatic generator can create potentials of more than 50,000 volts allowing sparks to jump a couple centimeters through dry air. Similar physics to the sparks created when shoes scuff on carpet, a moving rubber dielectric belt carries electrons away from the top sphere leaving it positive charged- as can be seen by the electrostatic repulsion of some Mylar strands. A small battery powered 3V motor drives the belt via the bottom pulley in this unit that costs less than $10 US.?With appreciation to @educational_innovations for sending me this device! 


Magnetic Suspsension Sculpture

This DIY magneits sculpture can be assemebled with these parts.  Bring a magnet into a craft shop to find some necklace chain that is non-magnetic. 

From Amazon/eBay: BUY NOW: Quilting HoopNeodyumium Sphere Magnets

Magnetic Suspension Sculpture: two neodymium magnets on chains suspended by their mutual magnetic attraction in this prototype kinetic sculpture. These powerful magnets hold the chains taut with about a 2cm gap. Made from a quilting hoop where the magnets connect under their own force to steel nails soldered on to non-magnetic chain.

Magnetic Sand Hourglass

Get one from these fine sources: 
From Educational Innovations: BUY NOW Magnetic Sand Timer 
From Amazon: BUY NOW Magnetic Hourglass 

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. 

Tensegrity for the Desk

Get this affordable physics tensegrity sculpture here:

From Etsy: BUY NOW: Tensegrity Sculpture

Tensegrity for the Desk: an elegant, and stackable, desk toy version of this popular tensegrity configuration by maker/designer Micah Murdoch. Constructed from poplar wood, the design assembles easily with clever ball and socket connectors at the ends of the nylon support lines (3 long, 1 short). Stacking them seems to only increase the illusion of floating with the subtle way these structures defy gravity. Another fun configuration of tensegrity concept, invented by Kenneth Snelson and made famous by the architect Buckminster Fuller in 1949.


Triple Pendulum Chaotic Fidget 

Get this chaotic fidget spinner here:

From Amazon: BUY NOW: Triple Pendulum Spinner

Triple Pendulum Chaotic Fidget: This interesting spinner is made from stainless steel and features three physical pendulums each mounted with their own low friction bearing. In slow motion one can see the kinetic energy and angular momentum is transferred from one pendulum to another as the entire device rotates, with some spinning rapidly and others rotationally at rest- the intricacies chaotic motion, characterized by extreme sensitivity to initial starting conditions, tiny differences in how the system is released leads to dramatically different outcomes each time.

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 

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! 


Moiré Kinetic Wheel

Get this device (and other variations) here:

From Amazon: BUY NOW: Moiré Fidget Device

Moiré Kinetic Wheel: sold as a fidget toy this device has two plastic disks and each has a pattern of curved spokes that can rotate independently and produce interesting illusions of motion via moiré interference effects. Explore constructive and deconstructive interference patterns with this minimalist toy.

Balance Pteranodon

Get one here! 
From Amazon: BUY NOW Balance Pteranodon 
From eBay: BUY NOW Balancing Pteranodon

Balance Pteranodon: weights in the forward wing tips create a center of mass below this pterosaur's beak- making a system that can rotate and oscillate about a stable equilibrium condition. No magnets used or needed for this physics! Usually this toy is found in the form of a bird (direct dinosaur descendent). Pterosaurs are not dinosaurs, but are the largest animals to ever fly, and powered flight has only evolved four times: bats, birds, pterosaurs, and insects- in reverse order. 

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!

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.

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".