Get one here::
From pinkoi.com: BUY NOW: Walking Cat Pen
Animated Cat Floating Pen: motion animation via the barrier-grid technique as a floating slider glides against a striped background. “A Cat in a Pen, Walking” is a sublime creation of artist Satoshi Endo. Wonderful kinetic art moiré pattern motion that fits in a pocket.
I found this beautiful model on eBay and I'm not sure of its age or origin.
Grant Sanderson describes the elegant geometry behind this curious arrangement.
On YouTube: 3Blue1Brown descibes the Dandelin Spheres
Wikipedia also has a good description: the Dandelin Spheres
Here are some 3D print models of conic sections:
From Etsy: BUY NOW: Conic Section Models
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Dandelin Spheres: Slicing a cone with a plane can produce an ellipse, and two spheres encapsulated by the same cone will always have the small sphere touching one focus and the large sphere contacting the plane at the other focus. This beautiful acrylic model shows this geometry for one choice of cone width and dissecting plane angle- but it always true. This geometric construction is named for its inventor, French mathematician Germinal Pierre Dandelin back in 1822, and with it he proved theorems concerning properties of ellipses and other conic sections- mathematical entities that play a roll in much physics- including the orbits of planets. Fun math that I wish someone would have showed me back in high school!
Get this sculpture here:
From Etsy: BUY NOW: Squirclusion
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Squirclusion (Square Circle Illusion): from one particular point of view this sculpture looks like a circle inside a square, from another, a square inside a circle- a matter of perspective! From other viewing angles one can make out that the underlying curves for each circle/square component are four identical segments of a parabola conjoined. Another reminder of how a single perspective can be misleading. This math sculpture is available as a 3D print, expertly designed and produced by Pyrigan Puzzles.
I made this display as part of my set of class demonstrations.
Wikipeadia has a great article on Plank Units
Planck Mass Display: mₚ = 22 micrograms displayed using a flake of low density aerogel. Three main physics constants of the universe can be arranged into fundamental expressions for length, time, and mass. The constants c, the speed of light in vacuum, G, the gravitational constant, and ħ, the Planck constant can be combined as follows: Planck mass: mₚ = √(ℏc/G) ≈ 2.18×10⁻⁸ kg, Planck length: ℓₚ = √(ℏG/c³) ≈ 1.62×10⁻³⁵ m, Planck time: tₚ = √(ℏG/c⁵) ≈ 5.39×10⁻⁴⁴ s
While the Planck length and time are tiny in the extreme, the Planck mass can be macroscopic- if the mass is of very low density such as the flake of aerogel!
Get the classic here:
From Amazon: BUY NOW Mini Slinky
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How a Slinky Falls: amazing physics demonstration with this classic toy. The center of mass of the slinky spring falls with an acceleration of g- note in this slow motion video that the bottom of the slinky does not move until the spring is fully collapsed. Hooke's law plus gravity!
Out of production but often available here:
From Etsy: BUY NOW: Sydney Cash Glass
From eBay: BUY NOW: Sydney Cash Glass
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Moiré Op Art Vase: alternating squares of vertical and horizontal thin lines create morphing and intricate moiré interference patterns as the viewer moves their point of view. The constructive and deconstructive interference illustrated in this kinetic art piece is described by math that is found in many areas of physics. Printed on the bottom of this elegant design: “Sydney Cash MoMA The Museum of Modern Art Net York”
Get a standard Drinking Bird here:
From Amazon: BUY NOW: Drinking Bird Engine
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Wikipedia has wonderful details about the rich history (and further descriptions of the operational principals) of the Drinking Bird.
Rocking Stork: this species of drinking bird toy comes from the Czech Republic where each is crafted in blown glass by an artisan. This classic physics toy is a functional heat engine- cooling by evaporation at the head/beak leads to lower pressure in the top bulb, the pressure in the bottom bulb pushes the dichloromethane fluid (here dyed red) 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 bulb stays wet and cooler than the bottom this heat engine will continue to cycle.
Get a nice 3D print made here:
From Etsy: BUY NOW: Heart Gears
Or print it yourself:
From Thingverse: Download Free: Heart Gears Print Files
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Heart Gears: This 3D print is guaranteed to put your heart in a twist- comprised of eight bevel gears attached to an octahedron center block, with the axis of each gear oriented to the center of each face of the octahedron. Rotate any one gear 360 degrees and the heart shape will reform. Another amazing design by Emmett Lalish, first printed in 2014.
Get this amazing clock here:
From EngineDIY: BUY NOW: Nixie Tube Clock
Includes countdown and stopwatch functions too!
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Nixie Tube Clock: a timepiece featuring a blend of modern LEDs and the retro orange glow of neon excitation via vintage Nixie cold cathode tubes. The “Numeric Indicator eXperimental 1” or NIX 1 was introduced in 1955 by Burroughs Corporation and manufactured until the 1990s. The clock shown here uses modern electronics to power Russian versions called the ИH-12 where the numbers are stacked so the front symbols obscure each lighted cathode minimally: from back to front 1320984756.
Get an amazing reproduction here:
From engineDIY: BUY NOW: Tesla's Egg of Columbus
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Get an aluminum phiTOP "egg" here: BUY NOW phiTOP
Tesla’s Egg of Columbus Replica: an egg of brass mysteriously spins and stands upright in this museum quality replica of Tesla’s famous demonstration from the 1893 World’s Fair in Chicago that first showcased the principles behind wireless power transfer and his AC induction motor. The base has no moving parts- instead special copper windings (very similar to Tesla’s original design) form four electromagnet coils on a circular steel core, and a special circuit supplies each with AC currents in such a way that a rotating magnetic field is created. This rotating magnetic field from the coils under the concave glass induces electric eddy currents to flow in the metallic brass egg. These currents within the conducting metal of the egg then create their own magnetic field, which by Lenz’s law oppose the initial fields underneath and pushes the egg to spin. Finally, the oblong egg stands up vertically (when spun with sufficient rotational velocity) due to physics similar to that of the tippe-top. Flipping the switch reverses the rotation direction induced by the coils.
This vintage toy still has versions in production: Get one here:
From Amazon: BUY NOW: Dolphin Kinetic Desk Toy
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Kinetic Dolphin Desk Toy: a vintage kinetic sculpture based on the regular periodic motion exhibited by a physical pendulum system. Two weighted dolphins are connected to an armature with a pivot axis that can roll with minimal friction on a support. The inertia of the dolphin assembly allows for many minutes of back and forth motion as the minimal friction slowly damps away the energy and the amplitude of each swing. The physics of harmonic motion as seen in desk toys.
Need a UV laser pointer? Get 3 lasers (one of each color) for under $10:
From Amazon: BUY NOW red+green+blue(UV) laser pointers
LEDs are really inexpensive these days- for $10 get this assortment of 350 LEDs to experiiment with:
From Amazon: BUY NOW: LED assortment
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For well explained details of the physics see this amazing video by Steve Mould
LEDs as PV Cells: the physics of solar cells (photovoltaic cells) is the reverse process of LEDs (light emitting diodes). Shown here is a very simple circuit I soldered together- a blue LED and red LED connected. When a stream of energetic photons (from a 405nm violet laser pointer) is directed onto the blue diode it produces enough current to power and light the red diode! I saw this demo from fellow physicist @richardvandewege and had to reproduce it for my collection- check out his profile for more fantastic physics via creative demonstrations.
Get this Urainum sample here:
From Luciteria: BUY NOW: 1 gram U238 sample in glass
Check out these: complete periodic element collections
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Uranium Metal: at Z=92 protons, uranium is the largest naturally occurring atom one can extract from the Earth. This one gram sample of depleted uranium (U238 with majority of U235 removed) is sealed in glass with pure nitrogen to prevent oxidation and keep its metal surface shiny. It is also radioactive and each U238 turns into lead (Pb206) through a complicated decay path, emitting alpha, beta, and gamma rays. Thousands of these energetic particles fly out of this small lump each second even though U238 has a half life of 4.47 billion years. A vintage Civil Defense Geiger counter counts hundreds of ionizing tracks per second at close range (but hardly any a few centimeters away- so not dangerous if handled appropriately).
The team at MetMo release these cubes for sale periodically:
From MetMo.co.uk: BUY NOW: MetMo Cube
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MetMo Cube: art from precision metalworking technology- a wire EDM (electrical discharge machine) can cut out two ovals from a 0.5 kg cube of solid stainless steel, and leave a gap of less than 0.05mm around the cutouts! The EDM process, sometimes called spark machining, removes material from the work piece by a series of rapid current pulses, that when bathed in dielectric liquid creates electric arcs that “vaporize” a precise bit of metal with every pulse. A 3D printed base is mounted to the bottom to create a tight seal and connect the two chambers so air can transfer between allowing pneumatic manipulation, and the satisfying slow descent (video in real time). From machinist/artist Paegan Ward and the MetMo (Metal in Motion) team.
Get this display here:
From Etsy: BUY NOW: Noble Gas Display
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Glowing Noble Gas Collection: five noble gasses are subjected to the high frequency electric field of a miniature Tesla coil. Encased in acrylic and carefully labeled, this spectacular display collection is the creative work of Tim and Cory Marriott of Engineered Labs Protoshop LLC- and each display comes with this Tesla coil! The high frequency/high voltage field of the coil transmits energy through the thick acrylic to excite the atoms of these gases, revealing the unique color of each gas, which is actually due to a mix of photon frequencies emitted from electron energy transitions specific to each element- the basis of spectroscopy.
Get this high quality balancing bird here:
From Amazon: BUY NOW: Tipsy Metal Balance Bird
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Brass Balance Bird: weighted wing tips create a center of mass below the bird's beak- making a system in stable equilibrium. No magnets! This bird and stand are made of steel with a polished brass finish- a work of art- and useful too.
Get this replica here:
From Amazon: BUY NOW: Tesla's Egg demo
I reccomened a separate purchase to get this nicer "egg":
From EI: BUY NOW PhiTOP in Aluminum
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Click here for more on the PhiTOP and using magnetic induction to spin it up.
Tesla’s Egg of Columbus: an aluminum ellipsoid egg (PhiTOP) mysteriously spins and stands upright in this modern version of Tesla’s famous demonstration from the 1893 World’s Fair in Chicago that first showcased the principles behind wireless power transfer and his AC induction motor. Rotating magnetic fields from under the wooden platform induce electric eddy currents to flow in the conducting PhiTOP- these currents then create their own magnetic field which oppose the initial fields underneath and pushes the PhiTOP to spin. This version featured here differs from Tesla’s in that the rotating magnetic fields are created by, well, a pair of rotating neodymium magnets (revealed by lifting the top platform in this model). Credit to astrophysicist Kenneth Brecher, the creator of the PhiTOP, and this unique means of using a common lab magnetic stirrer to create the induced currents. Finally, the ellipsoid top stands up vertically (when spun with sufficient rotational velocity) due to physics similar to that of the tippe-top.
Get one here:
From Amazon: BUY NOW Vortex II Coin Bank
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Vortex II Coin Bank: interplay of potential energy of gravity and conservation of angular momentum- a simulation of a decaying orbit. Fun with every coin saved!