If I were to be secluded on a deserted island - which actually would not change much my daily routine - and was asked for five physics topics to take with me, one would be superconductivity. Superconductivity is the phenomenon of current flow with zero resistance in certain substances cooled down to low temperatures. Several reasons why the topic would be on my short list on the (hopefully tropical) island: (1) It involves a delicate microscopic mechanism that you would never be able to guess at unless you were both a genius and intoxicated at the same time; (2) The physics involved is one of the most profound techniques Nature uses to achieve a change of state - for example, it is the same one that is also responsible for the Higgs particle (see post on the "god particle") giving mass to all matter; (3) It involves a phase transition - a phenomenon whereby a state of matter undergoes dramatic change that reflects intricate microscopic dynamics; (4) It is one of the few places in Nature where the crazy effects of quantum mechanics - usually tucked into the microscopic world - peak out directly into our macroscopic world.
The first video demonstrate superconductivity, along with the magnetic pinning phenomenon in so-called Type II superconductors. The second video talks about a current practical application of this physics. All this is in preparation to a post coming up tomorrow on the actual detailed physics of superconductivity. In the meantime, enjoy.