AskDefine | Define levitation

Dictionary Definition

levitation

Noun

1 the phenomenon of a person or thing rising into the air by apparently supernatural means
2 movement upward in virtue of lightness [ant: gravitation]
3 the act of raising (a body) from the ground by presumably spiritualistic means

User Contributed Dictionary

English

Etymology

From the verb to levitate.

Pronunciation

Noun

  1. buoyancy
  2. the raising of something, such as a human body, using the power of the mind

Translations

Extensive Definition

Levitation (from Latin levare, to raise) is the process by which an object is suspended against gravity, in a stable position, without physical contact.
It is also a conjuring trick, apparently raising a human being without any physical aid. The illusion can be produced by clever mechanics, lighting arrangements and other means.

Physics

For levitation on earth, a force is required directed vertically upwards and equal to the object's weight. This can be achieved by, for example magnetic, electrostatic (i.e. electrically charged objects) or aerodynamic forces. By means of diamagnetic levitation even small live animals have been levitated.
Scientists have discovered a way of levitating ultra small objects by manipulating the so-called Casimir force, which normally causes objects to stick together by quantum force. This practice however, is only possible for micro-objects.
Aerodynamic levitation is seen in air hockey where jets of gas from the table push upwards against the puck. Levitating objects may also force air downwards e.g. VTOL aircraft and hovercraft. The use of an airfoil allows a fixed-wing aircraft or rotary-wing aircraft, such as a Helicopter, to fly by Bernoulli's principle. A sphere can be stably levitated in a stream of air without any type of control system, if conditions are right. This was merchandised as a toy, circa 1960.
The effect of levitation can also be achieved using the upthrust of air, with the levitating object having the same average density as air. The heavier parts are compensated with one or more tanks of Helium or other gas (or vacuum) having less density than air.

Further reading

  • Motion Mountain: The Free Physics Textbook ">http://www.motionmountain.net/}} esp. the section on levitation in the chapter on electromagnetism.

References

levitation in Bulgarian: Левитация
levitation in Catalan: levitació
levitation in German: Levitation
levitation in Spanish: Levitación
levitation in French: Lévitation
levitation in Korean: 공중부양
levitation in Italian: Levitazione
levitation in Dutch: Levitatie
levitation in Japanese: 空中浮揚
levitation in Norwegian: Levitasjon
levitation in Polish: Lewitacja
levitation in Portuguese: Levitação
levitation in Russian: Левитация
levitation in Albanian: Levitacioni
levitation in Slovak: Levitácia
levitation in Finnish: Levitaatio
levitation in Swedish: Levitation
levitation in Chinese: 悬停

Synonyms, Antonyms and Related Words

Privacy Policy, About Us, Terms and Conditions, Contact Us
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2
Material from Wikipedia, Wiktionary, Dict
Valid HTML 4.01 Strict, Valid CSS Level 2.1