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4-Dimensional Tape Measure

Start your own physics toy collection with a subscrition to the Curiosity Box

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4-Dimensional Tape Measure: a unique measuring device that came in my latest @thecuriositybox subscription. In relativity, time is incorporated as a special 4th dimension with the 3 dimensional space coordinates, and indeed this tape measure transforms into a pendulum which can produce swings of precise time intervals allowing comparison and measurement of this special dimension. Even better- this tape measure is calibrated such that when extended to a length of 1 meter one swing takes 1 second (period, back and forth, T=2s), which seems like a challenging engineering problem to solve! The tape measure includes markings for a number of periods from 0.5s to 3.5s. As is taught in first semester physics classes, the period for swings of small amplitude is well approximated by T=2π√(L/g) where L is the length of the pendulum and g the acceleration of gravity. If we want a period of 0.5s which is 4 times smaller than the 2.0s, this formula tells us the length should be 16 times shorter and indeed the tape is marked at 6.2cm for this period taking into consideration the center of mass of the pendulum. Galileo first noted the mathematical regularity of such systems and Christopher Huygens created the first pendulum clocks in 1656 revolutionizing time keeping. Another amazing creation in time and space from VSauce and the @thecuriositybox team. 

Tesla’s Egg of Columbus

PhiTOPs are available in Aluminum and Brass: 
From Etsy: BUY NOW PhiTOP in Brass 
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: a copper 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 copper PhiTOP- these currents then create their own magnetic field which oppose the initial fields underneath and pushes the PhiTOP to spin. This version 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. 

HeNe LASER

Inexpensive lasers available here: 
From Amazon: BUY NOW: Red+Green+Purple Laser Pointer

Vintage HeNe lasers often found here: Search Now: HeNe Laser

The only available source I know of for projection holograms at this high resolution is this supplier of industrial samples 
From MaterialSampleShop.com: Diffractive Optical Element Sample 

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HeNe Laser: before there were diode based laser pointers, laser beams were produced by exciting mixtures of gases with high voltage and placing a mirror at each end. This vintage laser is based on the original laser design from Bell Labs in 1962 and has just such a configuration and uses a mixture of helium and neon. The red 632.8nm coherent beam comes from Light Amplification through Stimulated Emission of Radiation (LASER), and photons of this wavelength are one of the spontaneous emission lines of Neon. However, if these photos are reflected back into the excited gas they can produce stimulated emission where a photon is emitted of the same frequency- and in the same direction- as the reflected photon. This happens over and over producing a beam between the two mirrors, and one mirror is only a partial mirror allowing the photons to leak out one end forming the beam. A diffraction grating reveals the many emission lines of the excited gasses, but only the one red frequency participates in the LASER process in this design. This vintage educational model (with transparent housing) is a lucky recent find on eBay. 


Halloween Neon Glow Bulb 

Similar neon discharge glow bulbs can still be found:
From Amazon: BUY NOW: Neon Glow Bulbs
From Etsy: BUY NOW: Neon Glow Bulbs

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Halloween Neon Glow Bulb: the pumpkins, with a high voltage between them, glow orange with light from the emission spectrum of the excited neon atoms of the low pressure gas within the bulb. The ghost glows from a coating of phosphor which is stimulated to emit green light by ultraviolet (and invisible) photons. Excited neon atoms emit photons both in the visible (mostly orange and yellow wavelengths), and also in the UV wavelengths, and these ultraviolet photons are absorbed by the phosphorescent coating on the ghost plate which then emit the absorbed energy as green light. Amazing physics in a light bulb! 

Ghost in the Mirror

Get this halloween decoration here (plastic and not well made, but does work!) 

From eBay: BUY NOW: Ghost in Mirror 

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Ghost in the Mirror: the mirror pane is only partially silvered, so it reflects light well but still allows light to shine through (sometimes called a “two-way” mirror). If the room is well lighted the ghost behind is hidden- until it is lit up from behind via a motion sensor making its presence known! This physics trick was used by Disney for the Haunted Mansion ride where hitchhiking ghosts join the passengers as they move past mirrors.

Neon Flicker Flame Campfire

Get this night light here:

From Amazon: BUY NOW: Ghosts at Campfire

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Neon Flicker Flame Campfire: a night light for the Halloween season with two cute ghosts roasting marshmallows- however there is no flame, but instead the light is due to emission spectra from excited neon gas as a result of a discharge electric current from the 120V house mains. The flickering effect comes about because the glowing current flow will increase the temperature near it, which raises the local pressure and affects/raises the breakdown voltage- so the glow from one area can only last as long as it takes to heat up and raise the breakdown voltage which then briefly kills the current in that area. In other physics, a diffraction grating shows that the gas is indeed neon, which only emits light at specific emission wavelengths, here mostly reds with some bright yellow lines at AC house voltages. 


Vintage Bulb Spectra

Get this diffraction grating here: explore light source spectra! 

From Amazon: BUY NOW: 500 line/mm diffraction grating

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Vintage Bulb Spectra: emission line spectra identify the gas within these two vintage discharge glow bulbs- revealed here by a 500 line/mm diffraction grating. The color of each gas is due to a mix of the colors emitted from electron energy transitions specific to each element, the basis of spectroscopy.

Spooky Flourescent Mineral Sculpture

Find the sodalite bright orange fluorescent syenite here (some carved):
From Etsy: BUY NOW: Orange Glow Stones

365 nm UV flashlights available here:
From Amazon: BUY NOW: Convoy UB Flashlight

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Spooky Natural Mineral Fluorescence: this mini jack-o-lantern is carved from a rock-specifically grey syenite, which includes grains of the mineral sodalite. When exposed to long wavelength UV light, the carving lights up due to these sodalite crystals which fluoresce emitting the bright orange wavelengths. 🎃

Spooky Specs Holograms

Get these holospec glasses here (bats, jack-o-lanterns, skulls):
From Amazon: BUY NOW: Spooky Specs
The LEDs are available here: BUY NOW: Holloween Fairy Lights

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Holographic Halloween: put on these spooky specs and bats will suddenly appear around every point source of light! The “lenses” in these glasses are actually transmission holograms but with the image located at the farthest point in the depth of field. Holograms involve the physics of diffraction- notice the bats from the purple lights are smaller, and that there is a bit of orange light in the spectrum of the purple LEDs. Made by @americanpaperoptics3d with many more images available for Halloween and for other holidays as well. 


Animation Floating Pen

I got mine here:

From pinkoi.com: BUY NOW: Walking Man Pen

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Animation Floating Pen: this pen creates motion animation using the barrier-grid technique as the floating slider glides against a striped background. “A Man in a Pen, Walking” is a creation of artist Satoshi Endo. Fun kinetic art moiré pattern motion. 

Franklinite UV Phosphorescence 

Many nice specimens can be found here:
From Etsy: BUY NOW: Fluorescent Mineral Specimens

Need a UV laser pointer? Get 3 lasers (one of each color) for about $10): 
From Amazon: BUY NOW red+green+blue(UV) laser pointers

The UVC lamp used in this video is available here (see here the "Trtiple" and other well made and reasonably priced professional tools):
From WayTooCool LLC: BUY NOW: UV Lamps

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Mineral Fluorescence and Phosphorescence: a 405nm laser pointer excites the natural mineral Franklin calcite in the rock to briefly flash a red glow via “brief intense phosphorescence”(BIP) seen here as a trail of light following the violet laser dot on this spectacular specimen from the Sterling Hill zinc mine out of New Jersey. Next, shortwave UV reveals brilliant colors of fluorescence- Willemite fluoresces bright green and Calcite (with trace percent Manganese activator) glows pink/orange- and a green phosphorescence is activated at this wavelength which slowly fades after the lamp is switched off.

 

Tension Integrity Icosohedron: Tensegrity

A nice version of this tensegrity icosohedron is sold as a toy for tiny tots: 
From Amazon: BUY NOW Tensegrity Toy 

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I constructed this version by referring to the images and descriptions of tensegity on Wikipedia 

Tension Integrity Icosohedron: Six brass struts float isolated from each other but held in a stable configuration by a net of 24 connecting cables. I made this sculpture using hollow brass tubes and weaving through them a single strand of fishing line, which is connected after passing through each tube exactly four times. This configuration of three sets of parallel struts forms a Jessen’s icosahedron under tension, and was invented by the famous architect Buckminster Fuller in 1949.


BagleGen: Toroidal Plasma Generator 

More info here:
From TeslaCoilPro: Learn More: BagleGen and other Plasma Art

Variations available here:
From Amazon: BUY NOW: Plasma Toroid Lamps

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Toroidal Plasma Generator: an intricate dance of high intensity/high frequency electric and magnetic fields produce a ring of glowing plasma within a glass sphere containing noble gasses at low pressure. This BagleGen device is the latest in high tech kinetic art by creator Zerg Dragonymous of @teslacoilpro. What most amazes me here is how these very complex fields can be produced by circuit of only a few components- the main structure in the base is a cooling fan with a huge heat sink attached to a MOSFET transistor that sits centered below the induction coil. An amazing device for the serious hobbyist!

 

Fiber Optic Cactus Lamp

Vintage fiber optic lamps like this one are available on eBay or Etsy most of the time: 
From Etsy: BUY NOW Vintage Fiber Optic Flower
From eBay: BUY NOW Vintage Fiber Optic Flower
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Fiber Optic Cactus Lamp: a vintage fiber optic lamp from the 1980s in excellent working condition. The fiber bundle is illuminated by a halogen lamp in the base and the color shifting patterns are generated by a rotating color wheel placed between the light source and the fiber optic bundle. The label on the bottom reports: Model YS-800 from the Yirng Shehng Company 1988. 


TV Rock: Satin Spar

Get samples of Satin Spar here 
From Etsy: BUY NOW: TV Rock: Satin Spar

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Natural Fiber Optic Conduit: a special crystalline form of the mineral gypsum acts as a natural fiber optic image conduit in this square cut specimen with polished ends. Morocco seems to be the main source of this fibrous form, called satin spar gypsum, which exhibits pearl like luster and chatoyancy along two axes and transparency along the direction of the fibers. Each natural crystal microfiber extends the length of the rod and acts like a man made glass fiber where the index of refraction is just right to allow internal reflection to propagate light from one end to the other.

CMY Platonic Solids

Available from these sources:
From CMY Cubes: All 5 Platonic Solids
From Amazon: BUY NOW: CMY Cubes and More

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CMY Platonic Solids: The five famous convex regular polyhedra with thin film coatings, Cyan, Magenta, and Yellow, that allow filtering of the light that enters or leaves particular facets of each acrylic prism. I was struck by the intricate patterns produced in each object’s shadow by the refracted light- especially as the objects rotate. 

Electric Motor Build

Get an easy to assemble kit here: 
From Amazon: BUY NOW Simplest Motor Kit 

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Electric Motor Build: One of the most important inventions consists of only three basic components as shown here: coil, magnet, and a battery with lead wire posts. The wire of the spinning coil has an insulating coating on it- and this coating is carefully scrapped off one side of the thin wire on each end. When current passes through the coil it becomes an electromagnet and the permanent magnet repels it making it spin- as it turns the current goes on and off depending on if the copper wire posts are in contact with the bare wire side (current on) or the part of the wire with the insulating coating intact (current off). When the current is off momentum keeps the rotation going until the next push. The physics of converting electric energy to rotational kinetic energy- and a fun DIY project!