Superconductivity and carbon nanotubes, are Type I, while almost all impure and compound superconductors are Type II. Conversely, a spinning superconductor generates a magnetic field, precisely aligned with the spin axis. The effect, the London moment, was put to good use in Gravity Probe B. This experiment measured the magnetic fields of four superconducting gyroscopes to determine their spin axes. This was critical to the experiment since it is one of the few ways to accurately determine the spin axis of an otherwise featureless sphere. Superconductivity was discovered on April 8, 1911 by Heike Kamerlingh Onnes, who was studying the resistance
Groningen back to 1614. After the University of Leiden, it is the second oldest Dutch university. The university educated the first female student, Aletta Jacobs, the first Dutch national astronaut, Wubbo Ockels, the first president of the European Central Bank, Wim Duisenberg and two Nobel prize winners, Heike Kamerlingh Onnes and Ben Feringa. 200,000 people were either students, teachers or researchers at the university. Groningen has the highest percentage of students by total population, approximately 25 percent. The city council has 39 members. With 9 seats, the social-liberal D66 is the largest party on the council. The social-democratic PvdA has 6