Editing Levitation (physics) (section)

==Magnetic levitation==
{{main|Magnetic levitation}}

[[File:Stickstoff gekühlter Supraleiter schwebt über Dauermagneten 2009-06-21.jpg|thumb|A [[high-temperature superconductor]] levitating above magnet]]

Magnetic levitation is the most commonly seen and used form of levitation. This form of levitation occurs when an object is suspended using magnetic fields.

[[Diamagnetic]] materials are commonly used for demonstration purposes. In this case the returning force appears from the interaction with the [[screening current]]s. For example, a [[superconductivity|superconducting]] sample, which can be considered either as a perfect diamagnet or an [[ideally hard superconductor]], easily levitates in an ambient external magnetic field. The superconductor is cooled with liquid nitrogen to levitate on top of a magnet becoming super diamagnetic. In a powerful magnetic field utilizing [[diamagnetic levitation]], even small live animals have been levitated.

It is possible to levitate pyrolytic graphite by placing thin squares of it above four cube magnets with the north poles forming one diagonal and south poles forming the other diagonal.<ref>{{citation|author=Waldron, Robert D.|title=Diamagnetic Levitation Using Pyrolytic Graphite|journal=Review of Scientific Instruments|volume=37|issue=1|pages=29–35|doi=10.1063/1.1719946|bibcode = 1966RScI...37...29W |year=1966|doi-access=free}}</ref> Researchers have even successfully levitated (non-magnetic) liquid droplets surrounded by paramagnetic fluids.<ref>{{citation|author=Singh, Chamkor|author2=Das, Arup K.|author3=Das, Prasanta K.|title=Levitation of non-magnetizable droplet inside ferrofluid|journal=Journal of Fluid Mechanics|year=2018|volume=857|pages=398–448|doi=10.1017/jfm.2018.733|url=https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/levitation-of-nonmagnetizable-droplet-inside-ferrofluid/DD631FF653EE08399CBB233301E381D5#|arxiv=1712.01500|bibcode=2018JFM...857..398S|s2cid=53607312}}</ref> The process of such inverse magnetic levitation is usually referred to as Magneto-Archimedes effect.

[[Image:A maglev train coming out, Pudong International Airport, Shanghai.jpg|thumb|A magnetically levitated (maglev) train departing [[Shanghai Pudong International Airport]] on the first commercial high-speed maglev line in the world]]

Magnetic levitation is in development for use for transportation systems. For example, the [[Maglev]] includes trains that are levitated by a large number of magnets. Due to the lack of friction on the guide rails, they are faster, quieter, and smoother than wheeled mass transit systems.

[[Electrodynamic suspension]] uses AC magnetic fields.