Magnetism
Magnetism was a physical phenomenon caused by magnetic fields, which were themselves caused by Electromagnetism. Something exhibiting magnetism was said to be magnetic or magnetized. If that was their primary function, they were called a magnet.

In nature 
In nature, planets and moons might have magnetic fields. These could potentially be used taped into for an energy source. () The breakup of planet Psi 2000 was characterized by dramatic changes in its magnetic field, including at one point a four degree shift of the whole field. ()

The rings of Saturn also caused some magnetic distortion, and magnetic force originated from the Questar M-17. () 

The Murasaki 312 had magnetic potential. ()

Magnetic storms were a hazardous phenomenon in space and on the surface of planets like Rigel XII. (, etc)

Solar flares might be indicated by large magnetic disturbances on the star surface. During the Dominion War, the crew of the  was even able to directly trigger a devastating solar flare after locating a magnetic instability on a star and increasing its magnetic gradient. (: )

Ionised hydrogen might generate magnetic currents. Nucleonic particles such as those found in polaric fields were also highly magnetic, and if accumulated might even create a diomagnetic field. ()

In 2266, an unidentified yellowish ore was found on Alfa 177, which was subsequently determined to be magnetic. Magnetic deposits were also present on the Torothan homeworld. (;)

Magnetic waves were present in the Parvenium system, and were surveyed by a Starfleet ship in 2368. Spatial rifts might also emit magnetic shock waves. (; )

A negative magnetic corridor connected two universes, one of matter and one of anti-matter. ()

At least one living magnetic organism was encountered, which was characterized by a magnetic flux pulsing almost like the beating of a heart. Furthermore, the non-corporeal Ux-Mal entity claimed at one point that their consciousness had been captured by the magnetic currents of Ux-Mal, though this was part of an elaborate lie. A Delta Quadrant space-dwelling lifeform was also capable of generating a strong magnetic field.

As a technology

Warp drive design 
Magnetic technology was widely used in starship design, in particularly in feeding of matter and anti-matter into the warp core. 

Generally, containing a volume of anti-matter might be done using a magnetic containment field or magnetic bottle, and transporting (as in beaming) it could be done in a magnetic vacuum field. (; )

The plasma flowing into the system was magnetic. (; , etc.) Antimatter containment relied on magnetic fields utilizing magnetic flow. On  ships, this was monitored using a magnetic force indicator. () Another key component in the containment of antimatter and prevention of warp core breaches was the magnetic interlock. (; ) The  also had magnetic interlocks at the warp core. The  featured magnetic capacitors on the matter and anti-matter injectors. One way of dealing with problems in the latter was resetting the magnetic fields through a magnetic quench. () This class also featured magnetic coils, and magnetic seals at the antimatter chamber. ()  starships used magnetic constrictors to align the positron stream, and constrictors were also used in the Intrepid-class. ()

Containment and shielding 
Due to being made out of feromagnetic material, Control's nanites could be defeated by magnetizing them which appeared to destroy the nanites. Spock magnetized the floor of a starship to defeat the nanites that came out of Kamran Gant's body () while  later did the same thing using the 's reaction cube to neutralize Control itself from where it was occupying Leland's body. ()

Magnetic shields were occasionally deployed to block transporters from beaming someone in or out a certain area. Beaming through a shield was possible with a code. Such a setup was present at Rura Penthe in the 23rd century and at Aldea a century later. (; )

Malurians were able to create magnetic barriers. ()

Magnetic envelopes could be created, and even tweaked so that anti-neutrons could pass through it but anti-gravitons could not. ()

Attachments and locks 
Magnets might be used to attach things. For example, on  ships the deflector dish was attached to the ship using magnetic restrictors. ()

Doors were often magnetically sealed. Magnetic seals were already in use aboard . The Amargosa observatory contained a magnetically-sealed hidden door. (; ;) 

Suliban helixes were aggregate structures comprised of vessels held in place by an interlocking system of magnetic seals. ()

Gravity boots, also known as magnetic boots, used magnetism to allow people to operate in environments with magnetic variances. (;)

Other applications 
In Federation starships, magnetic constrictors were present in the impulse thrusters of runabouts, and magnetic inducers in Type 15 shuttlepods. (;)

Intrepid-class ships might use magnetic spindle bearings, and their bridge consoles contained magnetic relays, which if overloaded could cause the console to explore. () 

The  contained a magnetic storage bay. ()

Holograms were illusions created by projections of light held in a magnetic containment field. ()

The slingshot effect depended upon seeking out the magnetic attraction of a sun. ()

The pain bands in use on Sigma Draconis VI were speculated to use a kind of magnetic lock by Montgomery Scott. ()

22nd century Romulan mine locked onto targets using magnetic spikes. Two centuries later, Federation antimatter mines had magnetic targeting capabilities. ()

Cobalt-fusion warheads as used by the Lysian Central Command utilized magnetic propulsion. ()

Lazarus claimed his species used magnetic communications satellites. ()

Jem'Hadar fighters featured magnetic flux couplers. ()

Magnetic devices could be used to control Dom-Jot balls and thus cheat in the game. ()

Magnetic leverage might be used to lift cargo along an orbital tether. ()

The Turkana IV Coalition, a cadre operating on turkana IV, gave their operatives magnetic implants to ensure their loyalty. ()

Magnetism in scans 
Magnetism could also be used as a sensor technique, through a magnetic sweep or a magnetic residual analysis. (; ) Magnetic signatures could be looked for to compare readings. Wiping a memory core with an microdyne coupler left a unique magnetic signature. (; )

However, "magnetic clutter" could make scans more difficult. ()

The Talosian community on Talos IV was found by detecting the magnetic field of their underground generator. ()

The Borg were found to leave distinctive magnetic resonance traces. This was a working theory of Lieutenant Commander Shelby and was confirmed on the site of the New Providence colony disaster. ()

Runabout hulls were made out of metallic composites that interacted with magnetic fields, the magnetic deflection of which caused extremely weak magnetic resonance patterns, which were distinctive enough to locate a runabout. Such weak fields could be detected with a differential magnetometer, a device developed in 2369. ()

In 2373, the ship's engineer of a  ship was ordered to intentionally slightly misalign one of the ship's nullifier cores, thus creating a small polarized magnetic distortion in space whenever the ship was in motion, making it detectable even though it was cloaked. ()

Figuratively 
A person may have also figuratively been said to have had a magnetic personality. James T. Kirk described Khan Noonien Singh as such upon first meeting him. Some time later, Kirk later in noted in his log that the women Harcourt Mudd peddled in had a magnetic effect on the male members of his crew, including himself. This was later revealed to be the result of the Venus drug. ()

Captain Kathryn Janeway, role-playing as Queen Arachnia, once remarked that Doctor Chaotica could not possibly resist her magnetism. () Data also once claimed to have a magnetic personality, though only as a pun. ()

Other information 
Spock wondered if the Metron force that captured the  in 2267 was gravimetric, magnetic or electronic in nature. ()

See also 
Hysteresis curve
Magnetic energy
Bio-magnetic energy
Gravito-magnetic force
Magnetic field
Magnetic field core
Magnetic pole
Magnetic plasma guide
Magnetic fluctuation
Magnetic flux
Magnetic waveguide
Magnetometric guided charge

External link 
 
Physics