Superconducting magnet issues "shaken" out of them, until they are eventually able to operate reliably at their full planned current without experiencing quenches. Although the idea of making electromagnets with superconducting wire was proposed by Heike Kamerlingh Onnes shortly after he discovered superconductivity in 1911, a practical superconducting electromagnet had to await the discovery of superconducting materials that could support large critical supercurrent densities in high magnetic fields. The first successful superconducting magnet was built by G.B. Yntema in 1955 using niobium wire and achieved a field of 0.7 T at 4.2 K. Then, in 1961, J.E. Kunzler, E. Buehler, F.S.L. Hsu,
Einstein's Sink Einstein's Sink Einstein's Sink is an antique sink that has been in use by the physics faculty of Leiden University since 1920. Originally the sink stood in the large lecture room of the old Kamerlingh Onnes Laboratory. It was taken to the new building when the physicists moved to the Leiden Bioscience park in 1977. Here it still stands in the current large lecture room (The De Sitterzaal of the J.H. Oortgebouw), continuing the tradition of washing the hands of visiting famous scientists. A short list of 'sink users' consists out of Paul Ehrenfest, Heike Kamerlingh Onnes, Hendrik Antoon Lorentz