All physicsfun toys

Liquid Xenon Ampule

Available here:

From Luciteria Science: BUY NOW: Liquid Xenon Ampule

Liquid Xenon Rapid Phase Change: this small sealed vial contains pure xenon gas at very high pressure- 65 atmospheres! When cooled to 16C (61F) the xenon gas undergoes a rapid phase change to liquid as seen here when the ampule is immersed in an ice water bath. The video is shown in real time and the liquid xenon returns to gas within a few seconds and the process can be repeated indefinitely. The vial is made of fused quartz and kept small (3cm long) to be able to contain the high pressure environment which allows for such a high condensation temp (usually much colder at -108C).

 

Dudeney's Dissection

A nice wood version is available here: 
From Etsy: BUY NOW Dudeney's Dissection 

Click here for other intresting versions of this puzzle

See both Wikipedia and Wolfram MathWorld for more details on the history and math of this geometrical oddity. 

Dudeney's Dissection: an equilateral triangle can be cut (dissected) into four pieces that will then assemble into a square. Interestingly the four parts are all different in shape (the green and yellow pieces are similar but not the same). This hinged model is comprised of precision machined and anodized aluminum, and can be folded back and forth between the two simplest regular polygons. It is not known if a similar three piece dissection is possible. Also called the haberdasher's problem and described in 1907 by Henry Dudeney it is the only 4 piece solution known.

Dodecahedron Infinity Mirror

This lamp is interesting, but the fabrication is low quality. Still, it is fun to see the internal reflections and it would make for a great party light. Definitely read the reviews before purchasing! ($30-$45 USD) 

From Amazon: Dodecahedron Infinty Lamp

Dodecahedron Infinity Lamp: lit from within by strips of LEDs the 12 plastic mirrored faces create a universe of interesting internal reflections. While the manufacturing quality of this item is pretty low, when the lights are off it looks pretty amazing.

 


Self-Propelled Homopolar Motor on Aluminum Foil Racetrack

I used neodymium disk magnets, small end = 1/2" diameter, Large end = 3/4" diameter. 
From eBay: 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.

Element 10: Neon 

Luciteria (highly recommended) sells this cube and 80 other elements in many formats- start your collection today! 

From Luciteria: BUY NOW: Lucite Cube Element 10 Neon

Need a mini Tesla Coil? Click here for details: Mini Tesla Coil 

Element 10, Neon: a pure sample of the famous noble gas in a glass ampule encased within a lucite cube. But how can we know that the glass tube is actually filled with neon gas? If the sample is brought near the 50,000 Volt high frequency electric field of a miniature Tesla coil, the gas will glow with the characteristic orange light from the electron energy transitions specific only to neon. Note that the glow deceases as the sample is moved away from the coil in proportion to the electric field intensity- and that there is an excitation threshold, the gas needs a higher intensity (closer to coil) to initiate the glow discharge but will still glow when moved further away. 


Andrew's Space Wheel

This vintage 1970s item available now on eBay 
From eBay: BUY NOW Andrews Space Wheel 

Andrew's Space Wheel: kinetic art desk toy from the 70s- the rotor will stay in motion for weeks, until the hidden 9V battery is depleted. The rotor has a magnet at the end of each spoke- a coil and circuit identical to that of the "Top Secret" mystery top that I've posted about gives these magnets a push as the rotor passes through the middle- conservation of energy and angular momentum does the rest! 

Lava Lightning Lamp

Similar itmes available here: 
From eBay: BUY NOW: Lighting Plasma Lamps

Lava Lightning Lamp: low pressure noble gasses glow due to discharge from high voltage and stimulate colored phosphors to emit yellow, blue, and red in this vintage device by Lava. A small high frequency coil at center creates the high voltage potential between the center electrode and the outer glass casing which is coated with a thin transparent film of metal. Current flow through the thin gas produces the glowing zigzagged path like that of lightning but more rounded. Shown here in 480 fps slow motion. Another of my vintage plasma lamps in my collection. 


Coin Escape Puzzle

Available here: 
From eBay: Search NOW: Coin Escape Puzzle 

From Amazon: BUY NOW: Coin Escape Puzzle

Another coin escape puzzle (fits US Dollar), the YOT: 
From Amazon: BUY NOW 
Silver Dollar Escape Puzzle

Coin Escape Puzzle: physics brain teaser- remove the coin without breaking the container or using any tools other than your hands. Of course you spin it to get the quarter out- but exactly how? The solution to this puzzle (like others featured here) relies on some fun basic physics of spinning things. Answer below and swipe to reveal solution. 

Thermochromic Safety Sticker

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

From StemCell Science: BUY NOW: Thermochromic Saftey Sticker

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


Tesla's Plasma Mug

This plasma mug was sold in the 1990s but can be found on eBay often:
From eBay: BUY NOW: Plasma Mug

An improved and beautiful version sold here:
From Etsy: BUY NOW: Plasma Mug

Tesla’s Plasma Mug: this double walled glass mug glows orange from the excitation spectrum of neon gas at low pressure. The base contains a high frequency transformer that generates high voltage electric fields (but at very low current) from 8 AA batteries- which excites the neon to glow, and also serves as a coaster. This crazy item was produced by Can You Imagine Toys in the 1990s- perhaps Tesla himself would have served a good beer in this mug! 

Four Marble Puzzle

Get this well crafted puzzle from Creative Crafthouse here: 
From Amazon: BUY NOW Crossroads Four Marble Puzzle 
From Etsy: BUY NOW Four Marble Puzzle 

Four Marble Puzzle: physics brain teaser- move all four marbles to their corner locations simultaneously. Each slot slopes down towards the center such that the marbles tend to stay at the center- so, how would one get them to roll outward at the same time? The solution to this puzzle (like others featured here) relies on some fun basic physics principles. Answer below and swipe to reveal solution. A beautiful and well-made puzzle from Creative Crafthouse. 


Raketti Puzzle

Versions of this puzzle avaioable fron these sources: 
From Etsy: BUY NOW Raketti Physics Puzzle 
From eBay: BUY NOW Raketti Physics Brain Teaser 

Raketti Puzzle: physics brain teaser- the challenge is to remove the cone topped cylinder from the hole without touching the bottom container (no fair using sticky tape or such). It can be done in a matter of seconds! The solution to this puzzle (like others featured here) relies on some fun physics principles. Answer below and swipe to reveal solution. 

Fluorescence and Birefringence in Calcite

Get a sample here: 

From eBay: BUY NOW Optical Calcite Crystal 
From Amazon: BUY NOW Optical Calcite Crystal 

Get inexpensive polarizing filters here: 
From Educational Innovations: BUY NOW Polarizing Filter Sheets

Need a UV laser pointer? Get 3 lasers (one of each color) for under $10 (including S&H): 
From eBay: BUY NOW red+green+blue(UV) laser pointers

Fluorescence and Birefringence in Calcite: two samples of calcite- each with different impurities that produce blue fluorescence for the small crystal and red fluorescence for the larger one under a 405nm violet laser. Also one can clearly see that the single laser beam takes two paths through the crystals- the speed of light in a calcite crystal depends on polarization because the refractive index is different depending on the polarization orientation of the light transmitted through it (swipe for demonstration). As a polarizing filter is rotated 90 degrees, one image appears and the other vanishes, showing that the polarization orientation of the light of the two images is indeed perpendicular. In addition the elegant rhombohedral nature of calcite crystals is obvious in this sample.

Popsicle Stick Bomb

Craft sticke work great:

From Amazon: BUY NOW: Stick Bomb Supplies

Amazingly: There is a Wikipedia entry on Stick Bombs and their physics

Popsicle Stick Bomb: a form of simple tensegrity, the elastic potential energy of the bent sticks is dramatically released under application of a slight concussive force such as an impact with a table top- shown here in forward and backward slow motion (swipe to see three more explosions). Shown here is one of the simplest constructions with 5 flat sticks woven into a spring-loaded configuration held in place by friction and tension induced by the bending of the wood. A nice demonstration of energy conversion- potential to kinetic.