ülijuhtivaks

"Ülijuhtivaks" is the Estonian word for superconductivity. Superconductivity is a phenomenon observed in certain materials at very low temperatures, below a critical temperature. In this state, the material exhibits zero electrical resistance, meaning that electric current can flow through it indefinitely without any energy loss.

Beyond zero electrical resistance, superconductors also display the Meissner effect, where they expel magnetic fields from their interior. This expulsion is perfect and complete, causing magnetic field lines to bend around the superconductor. This property is responsible for the phenomenon of magnetic levitation, where a magnet can be suspended above a superconductor.

The critical temperature at which a material becomes superconducting varies depending on the material. Some materials require extremely low temperatures, close to absolute zero (-273.15 degrees Celsius or 0 Kelvin), while others, known as high-temperature superconductors, can exhibit superconductivity at temperatures that are still very cold but achievable with less complex cooling systems.

The discovery of superconductivity by Heike Kamerlingh Onnes in 1911 was a significant breakthrough in physics. Since then, research has focused on understanding the underlying mechanisms of superconductivity and discovering new materials with higher critical temperatures and better properties. Applications of superconductivity are diverse and include powerful electromagnets for MRI machines and particle accelerators, efficient power transmission lines, and high-speed magnetic levitation trains.