Magnetic Sand Hourglass: ferromagnetic sand collects above a neodymium magnet in the wood base. Each particulate of ferromagnetic iron becomes a temporary dipole magnet in the presence of the magnetic field in the base. The tiny dipoles link up north ends to south ends, creating interesting patterns that reveal the magnetic field lines.
Get some magnetic viewing film here:
From Educational Innovations: BUY NOW Magnetic Viewing Film
Magneview Flim: making the invisible visible and revealing the hidden physics of our everyday world. Microscopic cavities in this green film are filled with oil and tiny flakes of Nickel metal- like compass needles, the flakes align with the magnetic fields revealing the complexity of the north and south pole domains of these magnets. Two of the disk magnets have multiple north and south poles and look like gears with teeth- these are rotors from small motors.
Available from these fine sources:
From Amazon: BUY NOW Magnetic Field Viewer Set (get the demo set)
Similar device here:
From Educational Innovations: BUY NOW Magnetic Field Viewer with Magnet
Iron Filings in Silicone Oil Suspension ( Iron filing field detector ): visualizing the invisible- the magnetic field lines around a horseshoe magnet. In the presence of a magnetic field, ferromagnetic materials (such as iron) temporarily become magnets. Here the iron filings become dipole magnets and link up and align like tiny compass needles to follow and reveal the magnetic field lines associated with the permanent magnet underneath. Viscous silicone oil temporarily keeps the iron particles suspended yet allows for rotation and repositioning under the influence of the magnetic field.
Available as a set, or individually (all come with the super powerful sphere magnet) here:
From feelflux.com: BUY NOW: Copper + Aluminum Feel Flux
Feel Flux Loop: original (copper) and the "Skill Flux" version (aluminum)- toys that use Lenz's Law to manipulate a very strong neodymium magnet. The magnet falls a bit faster through the aluminum even though the walls are thicker- Al is only about 60% as conductive as Cu- so it takes more material to induce the needed magnetic field using aluminum. Interestingly the Al tube is about half the mass of the Cu one, even though it is larger in volume.
Get this device here:
From feelflux.com: BUY NOW Feel Flux
Viewing the Feel Flux Magnetic Field: Magneview film reveals the powerful field of the neodymium magnet as it falls with terminal velocity through the copper tube of the Feel Flux toy.
Get this set here:
From Amazon: BUY NOW
Magnetic Viewing Cylinder
Dipole Magnet and Iron Filings: visualizing the invisible- the magnetic field lines around a dipole magnet. In the presence of a magnetic field, ferromagnetic materials (such as iron) temporarily become magnets. Here the iron filings become dipole magnets and link end to end to follow and reveal the magnetic field lines associated with the permanent magnet within the hollow tube.
Available on Etsy: BUY NOW Motion Ferrofluid Sculpture
Colored Ferrofluid Display Cells: spectacular metallic blue, gold, and black display cells by @czferro - colloidal ferromagnetic liquids in a specially prepared water-alcohol suspension. Curious behavior results from the interplay between magnetic force and surface tension. The gold and blue coloring appears to be from a thin coating at the boundary between the ferrofluid and the suspension liquid. Still exploring the details of the coloring and the specific makeup of the clear suspension fluid - both trade secrets it seems.
Diamagnetic levitation kits are available here: the racetrack magnets are a bit pricey though!
From eBay: BUY NOW Diamagnetic Levitation Kit
Educational Innovations has this affordable starter kit:
From Educational Innovations: BUY NOW Diamagnetic Levitation Kit
Diamagnetic Racetrack: thin pyrolytic graphite sheets levitate above powerful magnets. A set of five concentric neodymium magnets, alternating N-S-N-S-N comprise the racetrack and form the trapping field. Diamagnetic substances develop temporary repulsive magnetic fields only when they are in the presence of a magnetic field from some other source. Graphite of this sort is the most diamagnetic substance known.
Penultimate: magnetic levitation pen. A two dimensional magnetic trap suspends a ball point pen- in this design the point of the pen against a polished acrylic acts as a bearing to let the pen spin with minimal friction.
From logicsticks.com: BUY NOW LogicSticks Magnetic Toy
LogicSticks: strong neodymium dipole magnets embedded within tactile hexagons which allows for side to side connection (unstable equilibrium) and top to bottom connection (stable equilibrium). Here some unstable equilibrium constructions are triggered to self reconfigure into a stable stack- shown in 240 fps. Thanks to @logicsticks (Mitchell John) for sending me this well designed magnetic toy, and check out his stream to see the amazing fidget manipulations that can be accomplished with some practice.
Get a set here!
From Amazon: BUY NOW Buzzing Magnet Set
Rattlesnake Eggs: polished barium- strontium ferrite ceramic magnets influence each other when many centimeters apart. Turn sound on--Wait for it! Sold as "buzzers" these magnets come together with multiple bounces creating a characteristic zipper sound. Most shops and online vendors incorrectly label these as hematite- a completely different substance that does not magnetize well.
Available from these shops in Germany:
From experimentis-shop.de: BUY NOW
From mabro.com: BUY NOW
Similar toys available here:
From eBay: BUY NOW
From Amazon: BUY NOW
Tegu Car Sets
Toy Car with Magnetic Suspension Wheels: Simple block car with clever wheel design. Small neodymium magnets embedded in the block lock on to steel balls, which raise the vehicle and become free to rotate providing the wheels for this simple toy.
Levitron Tops were produced in the 1990s and are out of production and getting harder to find. Some models are still available here:
From eBay: BUY NOW
See my blog post for more about the physics of the Levitron Top
The Levitron: spin stabilized magnetic levitation- will fly for about 3 minutes or more per launch. The spin rate of the magnetic top must be just right for flight, not too fast or too slow. Also the weight of the top must be adjusted to within 1 gram to achieve equilibrium between the pull of gravity and the magnetic repulsion from the large donut shaped magnet in the wood base. Repost of my favorite physics toy in my collection.
Bismuth Diamagnetic Trap Levitation: neodymium cube magnet trapped between two pieces of strongly diamagnetic bismuth crystal. Diamagnetic substances only have magnetic fields of their own when placed in an external magnetic field from another source- here the cube shaped magnet supplies the field. Diamagnetic fields are pretty weak though so two large ceramic magnets are placed on each side and adjusted to help lift the cube magnet against gravity. Trapped in equilibrium by these magnetic fields, the slightest air currents can send the cube magnet dancing. Another amazing creation by Ernie McElhannon.
Get one here:
From feelflux.com: BUY NOW Feel Flux
Feel Flux: a toy utilizing Lenz's Law- a very strong neodymium magnet falls slowly down a copper tube as though passing through a viscous liquid. Moving magnetic fields produce electric currents in a conductor (such as copper). These currents then produce magnetic fields that have the opposite polarity to the initial field. So a falling magnet makes the copper tube briefly into an electromagnet that repels the magnet.
Gauss Gun: acceleration of steel balls through magnetic potential energy and cascading collisions. Four neodymium magnets provide the potential energy that is converted into significant kinetic energy of the end steel ball. The initial configuration has two steel balls on one side of each magnet- an incoming ball on the opposite side accelerates and impacts each magnet in turn sending each loosely connected second ball off with greater speed.