The discovery of superconductivity by Dutch physicist Heike Kamerlingh Onnes in 1911 marked a significant milestone in the study of materials at low temperatures. Onnes had been exploring the properties of various metals when he focused his research on mercury. By employing a method to cool the metal to a temperature of about 4.2 Kelvin, he was surprised to find that its electrical resistance dropped to zero. This phenomenon suggested a new state of matter that could conduct electricity without any loss of energy.

This unexpected result drew considerable attention from the scientific community. Onnes theorized that this behavior was a reflection of the quantum nature of electrons within the metal, leading to his work on the theory of electrons in superconductors. His findings were eventually published, providing a foundation for future research, including the development of theories like the BCS theory (Bardeen-Cooper-Schrieffer) decades later, which would explain superconductivity in a more comprehensive manner.

Superconductivity is distinguished from normal conduction, where electrical resistance leads to energy loss. The implications of Onnes's discovery reached far beyond theoretical physics. His work paved the way for technological advancements such as MRI machines, maglev trains, and various types of electronic devices that benefit from superconductive materials. The pursuit of room-temperature superconductivity continues to be an active field of research, demonstrating the lasting impact of Onnes's initial work.