Magic wheel
Encyclopedia
The magic wheel, or magnetic wheel is a wheel that continues to spin for a long time after being started, and is one of the earliest examples of an attempt at a perpetual motion machine. This device was invented in medieval
Bavaria
. It looked like a wagon wheel spinning on an axle, affixed to a base. The superstitious population of the time believed it spun by the power of magic.
The mechanism of the magic wheel used several large magnet
s (lodestone
s) affixed to the wheel's outside rim, like the seats of a Ferris wheel
. Each magnet was backed by a lead
plate "seat". An extra stationary magnet was affixed to the base. Each magnet on the wheel's rim was attracted to the magnet in the base on its downward approach, then prevented from turning over when the opposite pole of the magnet passed over in the wheel, thus being repelled upward. The magnets were not allowed to touch one another. This attraction-repulsion maintained inertia efficiently, similar to a flywheel
, such that the wheel spun from a very long time and was thought supernatural by some.
Incorrectly deemed by some to be a perpetual motion machine, the magic wheel eventually comes to a stop because of frictional losses at the central bearing. Proponents of free energy devices have advanced the theory that the lead plating interrupts the magnetic attraction between the rim magnets and the stationary magnet in sequence, thus permitting the wheel to continue turning and bring the next rim magnet into position. However, the presence of lead dampens magnetic fields equally in any directions (as a magnet's field
lines must stay continuous from pole to pole), and the symmetry of closed forces in the system means that no interaction between rim magnets and the stationary magnets could generate the net increase in energy necessary to keep the wheel rotating.
The magic wheel was an impressive invention for the Dark Ages, a time when even some European kings were illiterate. An early German woodcut depicts a magic wheel.
Middle Ages
The Middle Ages is a periodization of European history from the 5th century to the 15th century. The Middle Ages follows the fall of the Western Roman Empire in 476 and precedes the Early Modern Era. It is the middle period of a three-period division of Western history: Classic, Medieval and Modern...
Bavaria
Bavaria
Bavaria, formally the Free State of Bavaria is a state of Germany, located in the southeast of Germany. With an area of , it is the largest state by area, forming almost 20% of the total land area of Germany...
. It looked like a wagon wheel spinning on an axle, affixed to a base. The superstitious population of the time believed it spun by the power of magic.
The mechanism of the magic wheel used several large magnet
Magnet
A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, and attracts or repels other magnets.A permanent magnet is an object...
s (lodestone
Lodestone
A lodestone or loadstone is a naturally magnetized piece of the mineral magnetite. They are naturally occurring magnets, that attract pieces of iron. Ancient people first discovered the property of magnetism in lodestone...
s) affixed to the wheel's outside rim, like the seats of a Ferris wheel
Ferris wheel
A Ferris wheel is a nonbuilding structure consisting of a rotating upright wheel with passenger cars attached to the rim in such a way that as the wheel turns, the cars are kept upright, usually by gravity.Some of the largest and most modern Ferris wheels have cars mounted on...
. Each magnet was backed by a lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
plate "seat". An extra stationary magnet was affixed to the base. Each magnet on the wheel's rim was attracted to the magnet in the base on its downward approach, then prevented from turning over when the opposite pole of the magnet passed over in the wheel, thus being repelled upward. The magnets were not allowed to touch one another. This attraction-repulsion maintained inertia efficiently, similar to a flywheel
Flywheel
A flywheel is a rotating mechanical device that is used to store rotational energy. Flywheels have a significant moment of inertia, and thus resist changes in rotational speed. The amount of energy stored in a flywheel is proportional to the square of its rotational speed...
, such that the wheel spun from a very long time and was thought supernatural by some.
Incorrectly deemed by some to be a perpetual motion machine, the magic wheel eventually comes to a stop because of frictional losses at the central bearing. Proponents of free energy devices have advanced the theory that the lead plating interrupts the magnetic attraction between the rim magnets and the stationary magnet in sequence, thus permitting the wheel to continue turning and bring the next rim magnet into position. However, the presence of lead dampens magnetic fields equally in any directions (as a magnet's field
Magnetic field
A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;...
lines must stay continuous from pole to pole), and the symmetry of closed forces in the system means that no interaction between rim magnets and the stationary magnets could generate the net increase in energy necessary to keep the wheel rotating.
The magic wheel was an impressive invention for the Dark Ages, a time when even some European kings were illiterate. An early German woodcut depicts a magic wheel.