Superconductivity is unusual in science: an unexplained phenomenon which is easily repeatable and well documented. It is also commercially important. But because nobody knows exactly how it works, breakthroughs are approached with caution. The latest development in superconductivity may be a great leap forward, or just a big red herring.
The history of this field goes back to 1911 when Dutch physicist Heike Kamerlingh Onnes was exploring the resistance of metallic mercury at extremely low temperatures. When he reduced the temperature to around four degrees above absolute zero, electrical resistance suddenly dropped so low that his instruments could not