Budget physics

Rattlesnake Eggs

Get a set here! 
From Amazon: BUY NOW Buzzing Magnet Set 

Rattlesnake Eggs: polished barium- strontium ferrite ceramic magnets influence each other when many centimeters apart. Turn sound on--Wait for it! Sold as "buzzers" these magnets come together with multiple bounces creating a characteristic zipper sound. Most shops and online vendors incorrectly label these as hematite- a completely different substance that does not magnetize well. 

Sphericon Frame Roller

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From Etsy: BUY NOW: Quantum Sphericon

Sphericon Frame Roller: beautiful 3D printed version of a developable roller (an object that rolls where every point on the roller’s surface comes into contact with the plane upon which it rolls). The sphericon (based on a square) rolls in a straight line with a peculiar wobble motion and was discovered in 1980 by David Hirsch and is but one of a family of such rollers called polycons. 

Impossible Braid 

Get this nice example of mystery braid here:

From Art of Play: BUY NOW: Impossible Braid Key Fob

Here is a great video on how to make the mystery braid

See other Impossible Objects in my collection. 

Mystery Braid: challenge- how can three strands be braided if both sets of ends are connected? (swipe for reveal) A new addition to my collection of “impossible objects”, this leather key fob is braided from a single piece of leather, constructed by making two parallel slits but not cutting the ends. The solution is well known to those in the field of leatherwork- due to a twist of topology it’s possible to make this braid if the number of left strand over right crossings equals the times the right strand crosses over the left. Four strands braided this way is not mathematically possible, but 3, 5, or any odd number can be done!

 

 


The Physics of Tippe-Top Inversion

Get a nice tippe-top from this fine source: 

From Etsy: 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!

Fine Wood Tippe-Top

Handmade flip over tops available here: 
From Etsy: BUY NOW Flip Over Tops

From Educational Innovations: BUY NOW Tippe-Tops 

Fine Wood Tippe-Top: spinning things often have surprising physics! This lathe worked version of the famous flip-over top is made of ebony and wood from the pink ivory tree. Friction with the mirror 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. 

Fine Wood Tippe-Top

Handmade flip over tops available here: 
From Etsy: BUY NOW Flip Over Tops

From Educational Innovations: BUY NOW Tippe-Tops 

Fine Wood Tippe-Top: spinning things often have surprising physics! This lathe worked version of the famous flip-over top is made of ebony and wood from the pink ivory tree. Friction with the mirror 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. 


Color Flame Candle Spectrum

Color Flame candles available here:
From Amazon: BUY NOW: Color Flame Birthday Candles

Get the diffraction grating used in the video here:
From Amazon: BUY NOW: Diffraction Grating

or paper glasses version as party favors!
From Amazon: BUY NOW: Diffraction Glasses

Color Flame Birthday Candle Physics: the colored parts of these candle flames are due to excitation of specific chemical elements mixed into the wax. When viewed through a diffraction grating some of the prominent emission frequencies (electrons jumping between quantum energy levels) can be seen as “ghost” images to the side as the grating separates the light into the spectrum emitted by each flame. Most notably the yellow candle has a strong yellow/orange emission line from sodium, the red candle has similarly strong red and orange lines from strontium, and the blue and green candles have a bunch of overlapping violet/blue/green lines from copper and probably potassium. Note that glowing tip of the wick creates a thin line of the full continuous spectrum. 

Precession of a Gyroscope

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From Amazon: BUY NOW Gyroscopes 
From eBay: BUY NOW Gyroscopes 

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. 

Magnetic Sand Hourglass

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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. 


Well Balanced Cabernet

Similar wine racks available here: 
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Balance Wine Rack 

Many well crafted versions avaulable here:
From Etsy: BUY NOW 
Wine Bottle Balance

Acrylic Wine Bottle Balance

Well Balanced Cabernet: a carefully engineered acrylic version of this famous demonstration- the center of mass of the rack/wine bottle system is directly over the base providing unstable equilibrium for this balancing act. Suspended here is Hypothesis by Roots Run Deep, an excellent Napa cabernet sauvignon. 

Animallusions Zebra

Get this illusion here: 

from eBay: BUY NOW: Animallusions Zebra

The original DIY dragon from G4G 3: Dragon.pdf

Animallusions Zebra: an amazing version of the hollow face illusion where the zebra’s head appears animated, and gives the impression that it’s always looking in the direction of the viewer. This zebra seems inspired by the dragon illusion created for the 1998 Gathering for Gardner by the Binary Arts Corporation of Bill Ritchie et al. Some fun physics of perspective and psychophysics for your shelf.


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 

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.

Phonotrope Fluidity

Get these and other amazing phonotrope spinners here:

From Etsy: BUY NOW: Phototrope Animation Spinners 

Phonotrope Fluidity: more amazing phonotropes from apyrodesign. When the rate of rotation matches the rate of the smartphone video process the six spokes appear to become fluid with waves rippling outward. The precision fabrication of these spinners is specifically designed to interact with the video process, similar to the animation effect of a flip book, but in a repeating cycle like that of the phenakistiscope, the 1833 invention that started moving media animation that lead to the development of movies and video. Swipe to see another design with an illusion of rotating meshed gears.


Glow Trace Chaotic Pendulum Kit

This kit (usually part of a subscription) often available here:
From eBay: BUY NOW: Glow Pendulum Kit

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

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. 

 

PDLC Electric Field Induced Transparancy

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From Amazon: BUY NOW: PDLC Smartwindow Sample

and click here for the balancing dragon toy

PDLC Electric Field Induced Transparency: when a voltage is placed across Polymer-Dispersed Liquid-Crystal film, long skinny molecules align with the electric field allowing light to pass through without scattering- with the field off the molecules thermally randomize and then do scatter the light passing through, producing a milky white translucent appearance. This sample of a “smart window” is powered by a 1.5 Volt AA battery and has very thin metallic coating on the front and back. A fun demonstration of electrochromic materials.