Budget physics


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.

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.


Crushmetric Pen

Available here:

From Crushmetric: BUY NOW: Crushmetric Pen

Crushmetric Switch Pen: functional kinetic art based on materials science and tessellation origami techniques. The crushed state can be reversed over and over in this incredible design by artist/inventor Noah Deledda, also known for his similar sculptures created from aluminum cans. New wonderful and affordable physics art that is also a practical ballpoint pen.

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. 

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.


Sp!n Top

Get a Sp!n Top here:

From Art of Play: BUY NOW:  Sp!n Top

Sp!n Top: once set into motion the eye only perceives the punctuation mark ! in the center of a ring, with the vertical line seemingly suspended in space above the dot. The rate of spin is above the flicker fusion threshold of human vision, and the crossbars become blurred out and invisible- the effect is even more pronounced in person (hard to capture on video). Physics and psychophysics combine to produce this wonderful illusion!

In-Feed Google

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. 


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. 

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!

Micro Racer in a Glass

These micro racer cars are sold under many brand names, and most come with a clear sphere to demonstrate this centripetal acceleration phenomenon. 

From Amazon: BUY NOW: Micro Racer + Sphere

From eBay: BUY NOW: Micro Racer + Sphere

Micro Racer in a Glass: This tiny battery powered car overcomes gravity through centripetal acceleration and slight friction with the glass surface. With sufficient velocity the surface normal force supplies the centripetal acceleration. The car’s battery last for many minutes and is USB rechargeable.

Tensegrity for the Desk

Get similar tensegrity sculptures 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.


Mini Acoustic Levitator

Get this inexpensive device here:

From EngineDIY: BUY NOW: Mini Acoustic Levitator

Mini Acoustic Levitator: small pieces of styrofoam become trapped between areas of higher pressure induced by high frequency sound waves. Ultrasonic transducers placed at the top and bottom are basically speakers that emit sound waves at a frequency of 43,000 Hz, which corresponds to a wavelength of 8mm for dry air. If the transducers are positioned just right standing waves are produce with nodes of low pressure at half wavelength intervals- and low mass objects like these foam pellets will be suspended against gravity when placed near one of these nodes. Here we see a stack of three pellets with a spacing of about 4mm which is the expected distribution of the nodes. To place the pellets into the sound stream without disrupting the standing waves this device comes with a small screen with a handle which allows the sound waves to flow through the holes in the mesh and trap piece of foam. Although the device uses sound it appears silent as the frequency used is way above that which humans can hear (20Hz to 20kHz).

 

Mini Waving Tube Guy

Get this inexpensive and silly toy here:

From Amazon: BUY NOW: Wacky Waving Inflatable Tube Guy

This power supply reccomended: BUY NOW: 9V power supply

Mini Waving Tube Guy: the physics of fluid dynamics describes the flopping behavior of the famous dancing tube guy. Bernoulli’s principle tells us that when air is moving with a velocity, the pressure in the region of the moving airmass is reduced. When the tube guy stands strait, air escapes through his head and arms allowing a temporary steady velocity of flow which reduces pressure inside and he collapses and bends. When the tube is bent, airflow is cut off, and the tube inflates like a balloon building pressure until air can again escape through the top- and the process cycles back and forth between these two states creating the iconic dance moves. This desktop version uses a 9V battery to power the fan.

Mini-Drinking Bird Heat Engine

Small and large drinking birds available here:

From Amazon: BUY NOW: Mini-Drinking Bird Heat Engine

See more drinking birds in my collection

Mini-Drinking Bird Heat Engine: this hummingbird sized heat engine is the latest species added to my drinking bird collection. This little guy comes with the traditional top hat and his own plastic goblet- which is the perfect height for a standard drinking bird to share. Cooling by evaporation at the head leads to lower pressure in the top bulb, the pressure in the bottom bulb pushes the dichloromethane fluid 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 process repeats, and as long as the top stays wet and cooler than the bottom this heat engine will continue to cycle.