
The a magnet floating (levitating) above a superconductor cooled by liquid nitrogen, aka Meissner effect (Ѻ), discovered in 1933 by Walther Meissner and Robert Ochsenfeld; when the superconductor transitions to the superconducting state, it causes the magnetic field or magnetic flux to be expelled.

The a magnet floating (levitating) above a superconductor cooled by liquid nitrogen, aka Meissner effect (Ѻ), discovered in 1933 by Walther Meissner and Robert Ochsenfeld; when the superconductor transitions to the superconducting state, it causes the magnetic field or magnetic flux to be expelled.

In science, magnetism is the phenomenon, generally of attraction or repulsion, associated with magnetic fields, which are produced by moving charged particles, such as electrons flowing through a coil of wire or spinning in a permanent location. [1]

Overview
In 1644, French philosopher Rene Descartes published his effluvia theory of magnetism—supposedly based on Empedocles' theory of effluvia—which seems, in some way, to have been a possible precursor to James Maxwell’s 1873 electromagnetic theory. [3]

In 1716, Edmond Halley's made diagrams of magnetic field lines, or what he called "circulating effluvia", found placing a magnetic terrella on a level surface and scattered fine iron filings around it, which, after some gentle tapping, the filings settled into patterns (shown below). [2]

In 1774, Franz Mesmer began experimenting with iron filings and magnets on hysteria patients, by having them swallow the iron and then move magnets over their body; shortly thereafter he began to popularize the idea of "personal magnetism" or animal magnetism; one rendition of which is as follows: (Ѻ)

In 1830s, Michael Faraday, building on Halley, introduced the magnetic field lines model, aka lines of force theory.

In 1873, James Maxwell added together known magnetic phenomena with known electrical phenomena, to make the electromagnetic field theory of light or electromagnetism.

Quotes
The following are related quotes:

“If the magnetic force that has guided this particular compass – and what else was its source but the central order – should ever become extinguished, terrible things may happen to mankind, far more terrible even than concentration camps and atom bombs. But we did not set out to look into such dark recesses; let’s hope the central realm will light our way again, perhaps in quite unsuspected ways. As far as science is concerned, however, Niels is certainly right to underwrite the demands of pragmatists and positivists for meticulous attention to detail and for semantic clarity. It is only in respect to its taboos that we can object to positivism, for if we may no longer speak or even think about the wider connections, we are without a compass [see: moral compass] and hence in danger of losing our way.”
— Werner Heisenberg (1952), dialogue with Wolfgang Pauli on god and the soul (see: Heisenberg-Pauli dialogue)

“All energy flows according to the whims of the great magnet. What a fool I was to defy him.”
— Hunter Thompson (1971), Fear and Loathing in Las Vegas (Ѻ); favorite Patrick Fergus author

“I toss and turn, I keep stressing my mind, mind
I look for peace but see I don't attain
What I need for keeps this silly game we play .. play
Now look at this
Madness to magnet keeps attracting me, me
I try to run but see I'm not that fast
I think I'm first but surely finish last .. last.”
— Kid Cudi (2009), “Day ‘N’ Night” (Ѻ)(V), verse 2


Left: English natural philosopher Edmond Halley's 1716 diagram of magnetic field lines, which he called "circulating effluvia", found placing a magnetic terrella on a level surface and scattered fine iron filings around it, which, after some gentle tapping, the filings settled into patterns shown. [2] This was the precursor model to Michael Faraday's later 1830s magnetic field lines (lines of force) theory.

Left: English natural philosopher Edmond Halley's 1716 diagram of magnetic field lines, which he called "circulating effluvia", found placing a magnetic terrella on a level surface and scattered fine iron filings around it, which, after some gentle tapping, the filings settled into patterns shown. [2] This was the precursor model to Michael Faraday's later 1830s magnetic field lines (lines of force) theory.

See also
● Animal magnetism
● Electromagnetic force
● Electromagnetism
● Thermo-magnetism (1824)
● Floating magnets experiment

References
1. Clark, John O.E. (2005). The Essential Dictionary of Science. Barnes & Noble Books.
2. (a) Fara, Patricia. (2005). Fatal Attraction: Magnetic Mysteries of the Enlightenment (pg. 61). MJF Books.
(b) Halley, Edmond. (1716). “Article”, Philosophical Transactions (plate 2, pg. 389), 29.
(c) Edmond Halley – Wikipedia.
3. (a) Descartes, Rene. (1644). Principia Philosohiae (diagram, pg. 274) (part IV, articles 133-188). Publisher.
(b) Fara, Patricia. (2005). Fatal Attraction: Magnetic Mysteries of the Enlightenment (pg. 130-31). MJF Books.
(c) Baigrie, Brian S. (2007). Electricity and Magnetism: A Historical Perspective (pg. 16). Greenwood Publishing Group.

Further reading
● Gilbert, William. (1600). On the Magnet and Magnetic Bodies, and on That Great Magnet the Earth (De Magnete). Publisher.
● Knight, Gowin. (1748). An Attempt to Demonstrate, that all Phenomena in Nature may be Explained by two Simple Active Principles, Attraction and Repulsion: Wherein the Attractions are of Cohesion, Gravity, and Magnetism, are Shewn to be One and the Same; and the Phenomena of the Latter are more particularly Explained. Publisher.
● Cavallo, Tiberius. (1787). Treatise on Magnetism. Publisher.
● Maxwell, James. (1873). Treatise on Electricity and Magnetism. Publisher.

External links
● Magnetism – Wikipedia.