All physicsfun toys

Reflection and Refraction of a Cyan Laser Pointer

Get this beautiful new color of laser pointer here: 
From eBay: BUY NOW: 488nm Laser Pointer (Cyan)

Blocks of polished acrylic available here:
From eBay: BUY NOW: clear acrylic block

Reflection and Refraction of a Cyan Laser Pointer: a new affordable wavelength laser pointer that just came on the market- 488nm producing a beautiful hue of blue. The beam is made brightly visible as internal reflection constrains most of the laser light to propagate along the interior of this block of acrylic (similar to the physics of fiber optics).

Moiré Kinetic Wheel

Get this device (and other variations) here:

From Amazon: BUY NOW: Moiré Fidget Device

Moiré Kinetic Wheel: sold as a fidget toy this device has two plastic disks and each has a pattern of curved spokes that can rotate independently and produce interesting illusions of motion via moiré interference effects. Explore constructive and deconstructive interference patterns with this minimalist toy.

Stirling Engine

Get this very nice working model engine here, choose a configuration:

From EngineDIY: BUY NOW: Stirling Engine 
From EngineDIY: BUY NOW: Stirling Engine with Generator
From EngineDIY: BUY NOW: Stirling Engine Simple Vehicle  

Stirling Engine: an elegant model of an external combustion heat engine with dual reciprocating pistons which operates by cyclic compression and expansion of air. Heat one cylinder with the cute little alcohol burner and this model gets up to speed quickly. Pyrex glass allows one to view the hot cylinder in operation (shown here in slow motion) and this version of the model includes a small generator to convert some of the mechanical energy into electrical energy which then powers some LED lamps. This design is attributed to Scottish engineer Robert Stirling back in 1816- a working piece of the industrial revolution for your desk top!

 


Wireframe Ambiguous Cube

Get the files (or order one printed) here:
From MakeAnything's MyMiniFactory: BUY NOW: Illusion Cube 3D Print Files
From Shapeways: BUY NOW: Ambiguous Cube Illusion

See the other illusions my collection: Ambiguous Objects

Wireframe Ambiguous Cube: another innovation of the ambiguous object illusion invented by mathematician Kokichi Sugihara of Meiji University- this time a 3D frame of a cube transforms to a cylinder! A new 3D print design from @make.anything

Poly acrylamide Polymer Vanishing Act

Get some of these grow-spheres here: 
From Educational Innovations: BUY NOW Growing Spheres 

Poly-acrylamide Polymer Vanishing Act: these spheres of hydrophilic polymer have an almost identical index of refraction as that of water- thus when submersed they become invisible. Note the elasticity of these spheres from the way they bounce, while at the same time they refract their surroundings as a spherical lens. The super absorbent spheres start as hard crystals with a radius of 2mm and grow to 11mm when immersed in water. So much physics going on here! 


Levitation Lamp 

Get this fun lamp here:

From Amazon: BUY NOW: Levitation Lamp

Levitation Lamp: tapping the floating spherical magnet turns this LED lamp off and on in this interesting design. The magnet floats a couple centimeters from the surface of the base when plugged in, and feels springy to the touch. Within the base is a control system with adjustable electromagnet coils in a feedback loop with Hall effect sensors which allow for fine tuning of a magnetic field to precisely balance the pull of gravity. 

Drinking Dino Heat Engine

This dinosaur themed heat engine available here:

From Amazon: BUY NOW: Drinking T-rex Desk Toy

Get also: the related Drinking Bird Heat Engine 

Drinking Dino Heat Engine: So what physics presents did you get this year? I got this Dippy Dino heat engine- where cooling by evaporation at the head leads to lower pressure in the top bulb such that the dichloromethane fluid (colored green) rises up the neck making the T-Rex top heavy and the dino tips over dipping its face in the water and letting the fluid return to the bottom bulb. The process repeats as long as the top stays wet. A fun and silly variation on the famous drinking bird physics toy- and the T-Rex was a closely related ancestor to the dinosaurs that live today- birds! 


Horizontal Hand Boiler

This device available here:

From Edicational Innovations: BUY NOW: Horizontal Hand Boiler

Horizontal Hand Boiler: liquid-gas phase transition. The boiling point of dichloromethane is slightly below body temperature and heat from a hand will induce vaporization of the liquid which increases pressure in one bulb pushing the red (dyed) liquid through the glass pipe to the other bulb. The process can repeat by switching the hand to the other side, but as both sides heat up the transfer is less vigorous. An inexpensive toy demonstrating phase changes and other thermodynamic physics. 

Tiny Leaf Blower Coanda Effect Toy

Get the "World's Smallest Leaf Blower" here:
From Amazon: BUY NOW: Smallest Leaf Blower

An inexpensive supply of styrofoam balls available here:
From Amazon: BUY NOW: Styrofoam Balls Assorted

Tiny Leaf Blower Toy: this little battery operated blower is great for experimenting with the Coandă effect. Here an air stream attaches and wraps around the styrofoam ball trapping it in the center of the stream. As the air changes direction to flow around the ball, momentum is imparted to push the ball against gravity and levitating it in equilibrium. A cylinder constrains the airflow and temporarily changes the dynamics which allows the airstream to push the ball up and out- and if one aims carefully the ball will fall back into the Coandă effect trap. 

Pythagorean Puzzle

Available here: 
From Creative Crafthouse: BUY NOW Pythagorean Puzzle

Pythagorean Puzzle: a proof, in physical form, of one of the most famous equations concerning the sides of any right triangle. The area of a square with side c of the hypotenuse is indeed equal to the sum of the areas of the squares of side a and b. This kit also allows at least two other ways to prove this theorem named after the famous Greek mathematician from 500 BC. One of the most used formulas when calculating vectors in physics classes ?


Thermochromic Eclipse Postage Stamps

Available from the US Post Office and here: 
From Amazon: BUY NOW Thermochromic Eclipse Stamps 

Thermochromic Eclipse Postage Stamps: In commemoration of the total solar eclipse next Monday the US Post Office has released their first ever stamp featuring thermocromic ink. Thermotropic liquid crystals go from opaque to transparent during a phase change from a crystal to liquid state. Here the warmth of the hand reveals the face of the moon in front of the solar corona. The first physics toy stamp! 

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

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


Thermochromic Liquid Crystal Mood Necklace

Similar mood jewelry available here: 
From Etsy: BUY NOW Liquid crystal jewelry 

Thermochromic Liquid Crystal “Mood” Necklace: heat from a hand brings out the temperature dependent color change of the liquid crystal. The molecules of the liquid crystal change orientation and spacing during the phase transition from liquid (warm) to crystal (cool). The molecular configuration shift allows for different diffraction effects producing the color shift. 

The PiTOP

Well engineered brass spinning toys by SiriusEnigmas

From Etsy: BUY NOW: The PiTOP

The PiTOP: this beautiful brass cylinder has a radius of 1 inch, a height of 1/π inches, and displays the first 109 digits of π on its face. Spin this disk (best with sound on) and it will demonstrate some very interesting physics involving energy transfer and conservation of angular momentum. The edges of the cylinder are rounded and engineered to exhibit an optimum motion of a “spolling” coin, a motion that combines spinning and rolling (closeup shown in 240fps). As the disk’s angle of inclination decreases the speed of the rolling increases dramatically until the contact point with the mirror is moving in excess of 200mph. From the mind of physicist Ken Brecher, inventor of the PhiTOP. Note also that with the specified height, that the volume of this cylinder is exactly 1 cubic inch! 

Maxwell's Dynamical Top: Historical Replica

Get this accurate and beautiful 1/2 scale replica here:

From Machined Marvels: BUY NOW: Maxwell's Dynamical Top

Maxwell’s Dynamical Top: one of my favorite demonstrations of the strange properties of rotating bodies- shown here with a 1/2 scale but exacting replica of the famous “Dynamical Top” created and demonstrated by the great physicist James Clerk Maxwell in 1857. When this brass bell shaped top is spinning an interesting stability can occur- push on the pointed stem and the top will push back, forcing the stem against that object, and friction will cause the stem to roll along and trace the edge of the object. Note- magnets are NOT involved here. The key to this design is to make the contact point/tip of the top at its own center of mass, then any frictional force in contact with the stem will produce a torque about the contact point at a right angle to the direction of friction that creates the stabilizing force (students of physics may recognize application of the right hand rule here). This beautiful historical replica is now available from machinist and creator Jim Peever @machinedmarvels- and as far as I know the only other replicas of this device where made in the 1880’s!