Superconductivity a better environmental performance but could also improve public acceptance for expansion of the electric grid. Superconductivity Superconductivity is a phenomenon of exactly zero electrical resistance and expulsion of magnetic flux fields occurring in certain materials, called superconductors, when cooled below a characteristic critical temperature. It was discovered by Dutch physicist Heike Kamerlingh Onnes on April 8, 1911, in Leiden. Like ferromagnetism and atomic spectral lines, superconductivity is a quantum mechanical phenomenon. It is characterized by the Meissner effect, the complete ejection of magnetic field lines from the interior of the superconductor during its transitions into the superconducting state. The
Leiden if there's a Sunday involved) and includes parades, a hutspot feast, historical reenactments, a funfair and other events. The city has recently started to host the Leiden International Film Festival, the fastest growing festival of its type in the Netherlands. Leiden has important functions as a shopping and trade centre for communities around the city. The University of Leiden is famous for its many discoveries including Snells law (by Willebrord Snellius), the famous Leyden jar, a capacitor made from a glass jar, invented in Leiden by Pieter van Musschenbroek in 1746. Another development was in cryogenics: Heike Kamerlingh Onnes (1913