leijutusta

Leijutus, or levitation, is the phenomenon of an object or person floating in the air without direct physical support. In physics and engineering, leijutusta encompasses several distinct methods that counteract gravity by other forces, often using strong fields or wave interactions.

The principal mechanisms are magnetic levitation (maglev), which uses magnetic fields to suspend and often propel objects; diamagnetic levitation, which exploits the weak repulsion of diamagnetic materials in strong magnetic fields; superconducting levitation, which relies on the Meissner effect and flux pinning to achieve stable suspension; optical levitation or optical trapping, which uses tightly focused laser light to trap microscopic particles; acoustic levitation, which uses standing ultrasonic waves to hold small objects in midair; and electrostatic levitation, which uses electric fields to suspend charged particles.

Applications range from transportation, where maglev systems aim for high-speed intercity links, to laboratory research and industry, where levitation reduces contact and contamination; optical and acoustic levitation enable manipulation of small samples; and art and demonstrations have used levitation to illustrate physical principles.

Historically, levitation demonstrations have illustrated diamagnetism and other effects; researchers have levitated solids and, in controlled experiments, small living specimens in high magnetic fields, highlighting the relationship between material properties and magnetic response. In popular culture, levitation is a common motif in magic, folklore, and science fiction, often portrayed with varying degrees of scientific grounding.

See also: maglev, diamagnetism, superconductivity, optical tweezers, acoustic levitation, levitation in folklore.