On 8 April 2011 in Leiden, The Netherlands, the discovery of superconductivity by Prof. Heike Kamerlingh Onnes and his collaborators, Cornelis Dorsman, Gerrit Jan Flim, and Gilles Holst, was designated as an IEEE Milestone in Electrical Engineering and Computing. A Milestone Plaque was dedicated in the building where this discovery was made 100 years earlier to the day. The IEEE Milestones in Electrical Engineering and Computing Program honors significant technical achievements that occurred at least 25 years ago in technology areas associated with IEEE. This Milestone was the 110th to be approved by the IEEE Board of Directors since the IEEE Milestone Program was established in 1983. The Milestone Plaque was presented to the University of Leiden by Prof. Moshe Kam, President & CEO of the IEEE and accepted by Mr. Willem te Beest, Vice Chairman of the Executive Board of the University of Leiden. The presentation was part of an all-day celebration commemorating the discovery of superconductivity that included talks on the history of low-temperature research at Leiden, the discovery and current applications of superconductivity and prospects for future research in materials. More than two hundred scientists and engineers from around the world participated in the symposium and attended the dedication ceremony. The celebration was jointly organized and sponsored by the IEEE Council on Superconductivity, The University of Leiden, the IEEE Benelux Section, the Museum Boerhaave (Leiden), and Philips Research. Superconductivity is one of the most startling effects in physics in which, for certain materials, the electrical resistance drops to “practically zero” for temperatures below a critical temperature, unique to each superconducting material. It was first observed on 8 April 1911 by Prof Kamerlingh Onnes and collaborators at the University of Leiden while measuring the resistance of mercury at temperatures just a few degrees above absolute zero (-273ºC). In his notebook, Prof. Kamerlingh Onnes noted that “Kwik(zilver) nagenoeg nul,” which literally translates to “mercury near enough nul”, or possibly, “mercury practically zero”, which is the more commonly accepted translation. During the past 100 years, superconductivity has been observed in more than 10,000 elements, compounds, mixtures, and alloys with the highest known transition temperature to date, of minus 100ºC. A comprehensive microscopic theory of superconductivity in metals was proposed in 1957 by John Bardeen, Leon Cooper, and Robert Schrieffer (the so-called “BCS” theory) for which they received the Nobel Prize in Physics. A total of four Nobel Prizes in Physics have been awarded to scientists for their research in superconductivity. For some additional information about superconductivity and a list of references and links please refer to the IEEE Milestone nomination form. Photograph of Plaque for IEEE Milestone in Electrical Engineering and Computing for the Discovery of Superconductivity 1911 Photograph of plaque donated by Philips Research containing the Milestone inscription in Dutch The morning session of the “100 years in Superconductivity” symposium was held in the Leiden Schouwburg (Dutch for “theater”), which is one of the oldest and most beautiful theaters in The Netherlands. After registration and coffee in the lobby of the Leiden Schouwburg, the first talk was given by Prof. Dirk van Delft, (Director, Museum Boerhaave, Leiden), who has written a biography of Kamerlingh Onnes. Van Delft described the early low-temperature research at the University of Leiden and the liquefaction of helium by Kamerlingh Onnes and colleagues in 1908. This was followed by a talk by Prof. Peter Kes (Kamerlingh Onnes Laboratorium, University of Leiden), which dealt with “The Notebooks of Kamerlingh Onnes and the Discovery of Superconductivity” in which he described the history of the discovery of superconductivity and the very intriguing story on how the details of this discovery had been “lost” for almost a hundred years until they were found recently when several of Prof. Kamerlingh Onnes’s supposedly “lost” laboratory notebooks were “discovered” in the archives of the Museum Boerhaave. Leiden Theatre 1 Leiden Theatre 2 Leiden Theatre 3 Photographs of Leiden Theater where the morning session of the symposium was held. After the morning session, the attendees moved to the nearby Museum Boerhaave, the Dutch National Museum of the History of Science and Medicine, which has many very interesting exhibits including equipment, specimens, photographs, etc., dealing with low temperature research at Leiden University leading up to the liquefaction of helium and the discovery of superconductivity. The attendees had time for a leisurely visit to the low-temperature research exhibit as well as many other exhibits, and to enjoy a nice lunch and interesting conversations with their fellow attendees. The afternoon session was held in a lecture hall in the Kamerlingh Onnes Building that housed the Kamerlingh Onnes Laboratory where superconductivity was discovered in 1911 and is now occupied by the Faculty of Law of the University. The first talk, on “New Developments in MRI”, was given by Dr. Johan Overweg of Philips Research who described the principles and some of the medical applications of MRI that employ superconducting magnets as an enabling technology. MRI is one of the successful applications of superconductivity with more than 30,000 systems presently installed worldwide and about 2,000 new systems built each year. The final talk was by Prof. Jan Zaanen (Institute-Lorentz for Theoretical Physics, University of Leiden) who spoke on “Superconductivity and The Fundamentals of Physics of the 21st Century” in which he described the status of the theoretical understanding of the mechanisms responsible for the recently discovered high-temperature superconducting materials and how these studies are playing a central role in modern physics research. A booklet containing manuscripts of the four talks presented in this symposium was distributed to the attendees and is available in PDF format. Photograph of Kamerlingh Onnes Building where afternoon session of symposium was held and the dedication & unveiling of plaques was done. Bust of Heike Kamelingh Onnes commemorating the 100th anniversary of the liquefaction of helium in 1908. Kamerlingh Onnes’ motto defining his approach to research was “DOOR METEN TOT WETEN” which, in English, translates as “Knowledge through Measurement”. Following the symposium on superconductivity, there was the presentation and acceptance of the plaques followed by the unveiling ceremony. The first speaker in this ceremony was Prof. Wim van Etten (University of Twente, retired), Chair of the IEEE Benelux Section, who described the objectives, organization, and membership of the IEEE. The next speaker was Prof. Moshe Kam, President & CEO of IEEE, who described the role of IEEE in developing technology and formally presented the IEEE Milestone Plaque to the University of Leiden. Then, Dr. Henk van Houten, (General Manager of Philips Research) described the long-term relationship between Philips Research and the University of Leiden and then presented the second plaque, with the inscription in Dutch, to the University. Finally, Mr. Willem te Beest, (Vice Chairman of the Executive Board of the University of Leiden) accepted the Plaques on behalf of the University. Moishe Kam, President & CEO, IEEE Henk van Houten, General Mgr., Philips Research Willem te Beest, Vice Chair, Exec. Board, Univ. of Leiden During the presentation and acceptance ceremony, the two plaques had been mounted on the front wall of the lecture hall, hidden behind an IEEE Benelux Section banner. The unveiling of the two plaques was done cooperatively by descendants of the discoverers of superconductivity, Mrs. Agnes Kamerkingh Onnes-van Dedem, Mr. Hans Holst, Mr. Gerrit Jan Flim and Mr. Wieb Dorsman, who were joined by Prof. Moshe Kam, (President and CEO of IEEE), Dr. Henk van Houten, (Philips Research), Dr. Elie K Track, (President of IEEE Council on Superconductivity) and Mr. Willem te Beest (Leiden University) to jointly activate an electric motor which raised the banner and “unveiled” the two Plaques. Descendants of the discovery team members (L to R): Agnes Kamerlingh Onnes-van Dedem (widow of grandson Heike Kamerlingh Onnes), Wieb Dorsman (son of Cornelis Dorsman), Gerrit Jan Flim (grandson of Gerrit Jan Flim), Hans Holst (son of Gilles Holst). Unveilers of the Plaques (L to R): Henk van Houten (Gen. Manager of Philips Research), Moshe Kam (Pres., IEEE), Willem te Beest (Vice Pres., Exec. Board, Leiden Univ.), Elie Track {Pres., IEEE Council on Superconductivity). Eventually, these two plaques will be permanently mounted on an interior wall of the Kamerlingh Onnes Building which corresponds to the room in the old Kamerlingh Onnes Laboratory where the helium liquefier was located when helium was first liquefied in 1908 and where the initial experiments on superconductivity were performed on 8 April 1911, precisely 100 years before the dedication ceremony. As a memento of this event, the IEEE Council on Superconductivity had a special coin minted from niobium, the most commonly used elemental superconducting material, to commemorate the 100th anniversary of the discovery of superconductivity and the dedication of the IEEE Milestone Plaque. On one face of the coin was the well-known plot from the Onnes paper of 1911 showing the resistance of mercury going to “practically zero” at a temperature near 4 kelvin, and on the other face was the date, location and the names of IEEE organizational units that sponsored the dedication event. A photograph of this coin is shown below. 100th anniversary of the discovery of superconductivity commemorative coin (IEEE CSC). The acquisition of the Plaques and the organizing of the events that were held April 8th was the result of the hard work by the Organizing Committee which consisted of: Dr. Thomas van Beek, Faculty of Law, Leiden University Prof. Dr. Dirk van Delft, Museum Boerhaave, Leiden Prof. Dr. ir. Wim C. van Etten, University of Twente (retired), IEEE Benelux Section Prof. Dr. Peter H. Kes, Kamerlingh Onnes Laboratorium, Leiden University Dr. Martin Nisenoff, IEEE Council on Superconductivity The proposal for the creation of an IEEE Milestone to commemorate the discovery of superconductivity was initiated by Dr. Nisenoff, the Vice President for Awards and Recognitions of the IEEE Council on Superconductivity, with support from Prof. Kes. After the Milestone had been approved by the IEEE Board of Directors in November 2010, Prof. Kes enlisted the support of Prof. van Etten, Mr. van Beek and Prof. van Delft to assist in making the necessary preparations and arrangements for the symposium and for the presentation and unveiling of the two plaques. The support from Phillips Research, including the donation of a plaque with the Dutch inscription, was invaluable to the success of this anniversary event.