Get this super nice, affordable, and fun to assemble kit here:
From KiwiCo: 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 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.
The hoop used is just the inner circle of an embroidery hoop. Get one for a couple dollars here:
From Amazon: BUY NOW Wooden Hoop
The science writer Martin Gardner has published many books of physics tricks and simple but amazing science experiments like the one in this video. Highly recommended.
From Amazon: BUY NOW Martin Gardner's Science Magic: Tricks and Puzzles
Bottle, Hoop, and Nail Trick: with some practice, a snap of the wrist removes the hoop and the nail falls straight into the bottle. Newton's 1st Law as seen in slow motion- a mass at rest tends to stay at rest. (Best to watch with sound/audio) Balancing the nail on the hoop ensures the nail is directly over the top of the bottle. The hoop is removed so quickly that it does not interact significantly with the sufficiently massive nail, and thus the nail remains over the mouth of the bottle so that gravity pulls it in. G4G Week repost- a favorite from Martin Gardner’s collections of physics tricks.
Fairly simple to make- here are the inexpensive supplies needed to make a few of these motors.
AA batteries have a diameter of 14.5 mm, so a bottom magnet with a diameter of 15 mm is just right:
From eBay: BUY NOW Neodymium Disk Magnet
Wire that looks and works well is just 10 gauge ground wire. Inexpensive and available at any local hardware store-- or order a small quantity here:
From eBay: BUY NOW 10 gauge Copper Wire
Wikipedia has some good details on the physics of homopolar motors
Homopolar Motor: a minimalist electric motor- battery, wire, and magnet. This type of motor does not need a commutator- the polarity of the electromagnetic coil does not need to reverse. The challenge with this design is balancing the coil to center on the battery as it rotates. A favorite DIY physics toy!
I made this set of tumble rings from reading Martin Gardner's description in his famous mathematical recreations books- highly recommended:
From Amazon: BUY NOW Knots and Borromean Rings by Martin GardnerDescribes the Tumble Rings
From Amazon: BUY NOW Books on recreational math and puzzles by Martin Gardner Lots of physics and math toys in these pages!
Tumble Rings: the links in this chain are connected in a special way such that the top ring appears to tumble to the bottom- a compelling illusion!
Click this link for a gyroscope that will perform the same trick!
Spinner Fidget Trick: defy gravity!- a trick to try with a fidget spinner you might have in a drawer somewhere. For the trick to work the spinner needs to have most of its mass far from the center (not all spinners will work)- and you may need to drill a hole down its center to attach an axle. This Spinpal spinner has three heavy steel spheres placed to maximize rotational inertia, that along with precision bearings, gives this fidget toy properties of a quality gyroscope. Give the spinner significant RPMs and it will suspend from, and precess around, a string! Thanks to @spinpal for sending me this a while back.
Neodymium magnets will produce the largest gap when suspending a nail.
Please use exterme caution when handling these magnets.
From Amazon: BUY NOW: Neodymium Super Magnet
Magnetic Defiance of Gravity: a nail suspended between a chain and a powerful neodymium magnet. Ferromagnetic attraction over a distance of many millimeters, and a reminder of the presence of the typically invisible electromagnetic forces all around us. Make your own with a paperclip, string, and a refrigerator magnet- or get a neodymium magnet and see how massive an object you can suspend in air.
Here is the NdFeB neodymium magnet used in this video:
From Amazon: BUY NOW: Neodymium Disk Magnet
Please use cuation when handeling strong magnets like this one. Small nails, paperclips, staples and other houlshold object made with iron will interact interestingly with the magnetic feild.
Ferromagnetic Interaction: iron rich nails temporarily become dipole magnets in the presence of an intense magnetic field from a large neodymium super magnet. Here the neodymium disk magnet is set with its north pole pointing up, so the point of each nail becomes a south pole (repelling each other) and the head of each a north pole. Imbued with these temporary induced fields, the nails will try to align themselves with the neodymium dipole’s field like compass needles, and the nails will interact with each other in interesting ways.
Gallimum metal and a silicone mold to produce the spoon- available here:
From Amazon: BUY NOW: Gallium Mold Spoon Kit
Disappearing Spoon: the metal gallium has a melting point of 30°C (86°F) and will melt quickly when exposed to tea temperature hot water- or melt in one’s hand if handled too long. This spoon was made with a silicone mold (swipe to see process), and feels and sounds just like a regular spoon, except solid gallium is brittle and the spoon can shatter like glass if dropped. An amazing parlor trick as well as a classic and historical class demonstration.
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.
Here's the parts to make your own:
From eBay: BUY NOW Neodymium Spheres 15mm
From Amazon: BUY NOW Bare Copper Wire 10 gauge
The wire used for the Faraday Train has to be bare- so make sure it does not have any kind of clear coating on it. The solid grounding wire sold at hardware stores works great.
Here is a nice description of the Faraday Train and the physics of its propulsion.
Faraday Train: two magnets, one battery, and a coil of bare copper wire are the simple essence of this self propelled craft. The magnets conduct electricity, thus when put in contact with the coil current will flow creating a solenoidal magnetic field in the vicinity of the battery, which in turn pushes on the magnets at each end of the battery moving the craft along. The spherical neodymium magnets used allows the craft to slide along the coil with minimal friction.
Get inexpensive small motors and accesories for DIY projects here:
From Amazon: BUY NOW DC Motors Kit
A DIY project to see if just shaking a bolt at the right frequency could make a standard nut rotate and fall off. Similar physics to the phase locking propeller toy featured in my last post. Motivated by videos seen on Instagram where a brass bolt is placed in magnetic putty and the nut mysteriously rotates up and off- now convinced that vibration is how that effect is produced. Here a small DC motor spins an offset mass to produce the vibrations.
Get these 99.9% pure element Bi 83 cubes here:
From Luciteria: BUY NOW: Bismuth Element Cube
Many combinations of strong neodymium magnets will work, here are the versions I used:
From Amazon: BUY NOW: Cylindrical Neodymium Magnet
From eBay: BUY NOW: Tiny Neodymium Cube Magnets
See my video of other pure element cubes by Luciteria Science
Bismuth Diamagnetic Levitation: Element 83 (bismuth) is the most diamagnetic of the elements*. Here a small neodymium magnet is made to float between two 99% pure bismuth 10mm cubes which are held in precise configuration by friction with the parallel walls of the acrylic assembly I made. Diamagnetic substances only have magnetic fields of their own when placed in an external magnetic field from another source- here the tiny cube magnet supplies the field. Diamagnetic fields are pretty weak though so a powerful cylindrical neodymium magnet sits above the cubes and is adjusted to help lift the tiny cube magnet against gravity. *except for a special form of carbon known as pyrolytic graphite.
The Actuator mechanism is out of production but can still be found on eBay, comes with power supply, Expandagon kit, and connecotors that snap on to a Hoberman Spjere.
From eBay: BUY NOW: Hoberman Actuator
The spheres are still in production and come in various sizes and colors:
From Amazon: BUY NOW Hoberman Spheres
Hoberman Actuator with Sphere: This actuator mechanism creates kinetic art out of a Hoberman sphere, designed to smoothly expand and contract the isokinentic structure. The Hoberman sphere itself is a special assembly of foldable linkages consisting of rigid bars and simple hinges is kinematically over constrained- motion can only occur along the radial direction and the movement of any hinge creates motion in all the joints. The engineering and physics behind deployable space structures!
The .stl files are available here:
Origial desing by Emmett Lalish Download: Gear Bearing
Refined version featured here by Don Stewart Download: Honeycomb Gear Bearing
Similar prints available as fidget toys here:
From Etsy: BUY NOW: Gear Spinner Fidget Toy
3D Print Planetary Gearset: amazingly this gear set is printed assembled, with interlocking herringbone teeth. The gears will not come apart, in fact this design can only be accomplished by 3D printing the gears interlocked with each other. Designed and first printed by Emmett Lalish in 2013, and this version with refined precision and honeycomb by Don Stewart.
This inexpensive electrophorus set works great!
From Amazon: BUY NOW Electrophorus Demonstration Set
The container is just the middle part cut from a plastic water bottle, and the "hail" stones are Styrofoam craft beads:
From Amazon: BUY NOW Styrofoam Craft Beads
For Volta's Hailstorm to work, the beads must be coated with a conducting spray (here is what I used):
From Amazon: BUY NOW Staticide Spray
Wikipedia has a very nice description of the physics of the Electrophorus and how it is used to transfer electric charge.
Volta’s Hailstorm and Electrophorus: electrical forces due to electrostatic charge send foam beads flying in this version of the historic demonstration by physicist Alessandro Volta. The beads are covered with an electrically conductive coating allowing them to transfer charge from the environment to the plate of the electrophorus. The acrylic platform becomes negatively charged when rubbed with a paper napkin, but it is also an insulator so the charge on it can not flow on to the aluminum plate of the electrophorus. Instead the charge on the platform pushes electrons to the top of the plate (like signs repel) and touching the plate results in a spark that removes the electrons giving the plate a significant positive charge that will then attract the beads.
All the ingredients are available from your local market/drugstore. The trick is to find a dye that works for acetone, but will not color water- believe it on not blue glitter will color the acetone nicely and not change the salt water. Follow this link for details:
ChemEd X: Blog of Prof. Tom Kuntzleman
Of course Amazon has what you will need:
From Amazon: BUY NOW
acetone, blue glitter, food coloring, cool bottle
Salt Fractionation: two liquids that won’t stay mixed! Acetone (dyed blue) floats on top of the higher density salt water (dyed orange). Acetone usually dissolves in water through hydrogen bonding interactions, but solubility can be altered. In a process called “salting out” a sufficient amount of salt is dissolved such that the water molecules, which are much more attracted to the resulting Na+ and Cl- ions (through ion-dipole bonds), will then ignore the weaker acetone hydrogen bonds. This results in the spontaneous separation (shown here in real time) of the liquids no matter how well shaken up.