Budget physics

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

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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.

LASER Pointers + Diffraction Grating

Need a laser pointer? Incredibly, you can get 3 (one of each color) for under $20 (including S&H): 
From Amazon: BUY NOW Red+Green+Purple Laser Pointer

Rainbow Symphony has a nice selection of diffraction gratings and sun catchers:
From Amazon: BUY NOW: Diffraction Grating Toys

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

LASER Pointers + Diffraction Grating: three frequencies of laser pointer- Red (635 nm), Green (532 nm), and Blue (450 nm). Note that the distance between the intensity maxima (bright spots) is greatest for the red (long wavelength) and closest for blue (shortest wavelength) with the green in between. The diffraction grating is the same form as one of those rainbow fireworks glasses- this one from has 13500 lines per inch. 

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

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

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.


Drinking Bird Engine Experiment

Get this famous physics toy from these sources: 
From Educational Innovations: BUY NOW: Drinking Bird Engine 
From Amazon: BUY NOW: Drinking Bird Engine 

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

Wikipedia has wonderful details about the rich history (and further descriptions of the operational principals) of the Drinking Bird. 

Drinking Bird Engine Experiment: what happens if you feed a drinking bird alcohol? This experiment compares the drinking rate (time per one full engine cycle) of two identical bird devices- but the glass on the left is filled with 70% isopropyl alcohol whereas the glass on the right contains tap water. After wetting the tops of both birds we count how many times each one “takes a drink” over a 5 minute duration (shown at x6 speed). This classic physics toy is a functional heat engine where cooling by evaporation at the head/beak provides the operating temperature difference. Isopropyl alcohol has a more rapid evaporation rate than water for room temperature and low humidity- so which bird will win? 

Glow Trace Chaotic Pendulum Kit

This kit (usually part of a subscription) often available here:
Get amazing quatilty science kits delievered to your home- this glow pendulum is part of the Tinker Crate subscription. 
From KiwiCo: LEARN MORE: Tinker Crate Subscription

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

Glow Trace Chaotic Pendulum: this fun and amazing DIY kit features a UV diode to trace the intricate path of this double pendulum system on to a phosphorescent screen, revealing the physics of chaotic motion. It’s amazing that such complex motion can arise from a simple assembly of two pendulums, one attached to the end of the other. Chaotic motion, such as that observed here, is characterized by extreme sensitivity to initial starting conditions, tiny differences in how the system is released leads to dramatically different outcomes each time. 

 

Centripetal Switch

Get a siimilar light up top here:

From Amazon: BUY NOW: light up spin top

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Centripetal Switch: a very simple design allows sustained power to the LED only when the top is spinning. A floppy spring is attached to one side of the LED and when the top is spinning centripetal acceleration bends the spring to touch the metal flange to complete the circuit. Note that in operation the LED is not on the whole time, but flashes on and off due to vibrations affecting the simple spring switch contact, and when coupled with the frame rate of the camera, creates the light patterns seen here. Simple design, but lots of physics! 


Scale Solar System Sticker Set

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

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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.

Static Spheres

Get this inexpensive device here:

From Educational Innovations: BUY NOW: Static Spheres

Click here for other static electricity devices

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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

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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!


Thermochromic Safety Sticker

These stickers transition back and forth and can be used on many surfaces. Get some here:

From Etsy: BUY NOW: Thermochromic Saftey Sticker

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

Thermochromic Safety Sticker: the liquid crystal ester dye in this reusable sticker is calibrated to change color when the surface temperature exceeds 50°C (122°F)- that at which prolonged contact (more than 0.5s) will burn skin. Here the safety sticker is attached to a slab of aluminum and heated with a simple candle- it took about 3.5 minutes for the heat to distribute and bring the aluminum to the threshold temperature. When the surface cools the sticker again appears blank and can transition over and over again


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 

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

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! 

Reverse Cartesian Diver

Glass divers available here: From Amazon: BUY NOW Glass Divers 

The reverse diver needs a bottle with a oval shaped cross section. I used the bottle from this product- it has the right shape and size and the label comes off easily: 
 
From Amazon: BUY NOW Oval Shaped Bottle Source 

Inexpensive and fun diver kits available here: 
From Educational Innovations: BUY NOW Cartesian Diver Kits 

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

Wikipedia has the details on the Cartesian diver (and reverse diver). 

Reverse Cartesian Diver: physics puzzle (swipe for hint). On the left is a Cartesian diver- pressing on the bottle forces water into the glass diver, which then compresses the bubble in diver’s head allowing it to sink. On the right is a reverse Cartesian diver- again the bottle is pinched but this time the diver ascends- why? 

In-Feed Google 5


Dudeney's Dissection 3D Print

Get this set here!

From Etsy: BUY NOW: Dudeney's Dissection 3D Print

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

Dudeney's Dissection: an equilateral triangle canbe cut (dissected) into four pieces that will then assemble into a square. This 3D printed version comes as a puzzle- fit the pieces in each of two containers- a square and a triangle, which also makes it clear the two supplied shapes are of equal area. Fun fact: It is not known if a similar three piece dissection is possible. Also called Haberdasher's problem and described in 1907 by Henry Dudeney it is the only 4 piece solution known.

Chain Fountain

The best effect (highest fountain) is obtained by using #10 size chain with a bead diameter of 3/16" (4.8mm). This spool has 100 feet of chain, the same length as used in the video. 
From Amazon: BUY NOW #10 ball chain 
Wikipedia has the details on the discovery of the chain fountain, and for those that want the physics here is the paper: Understanding the Chain Fountain from Proceedings of the Royal Society A, 2014 

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

Chain Fountain: as the chain flows out of the glass under the pull of gravity the beads don't simply roll over the edge but instead arc up upward like a fountain. As each link is pulled and tilted upward the adjacent link is tilted downward and pressed into the pile- by Newton's 3rd law the pile presses back pushing each bead upward into the air. A segment of the video is shown in slow motion where the fountain is at maximum height. This phenomena was recently discovered by Steve Mould (more to be seen at his YouTube channel) and the details of the physics is described in the Proceedings of the Royal Society by Biggins & Warner (2014). 

Balance Pteranodon

Get one here! 
From Amazon: BUY NOW Balance Pteranodon 

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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.