Leiden University at the university. The learning and reputation of Jacobus Gronovius, Herman Boerhaave, Tiberius Hemsterhuis and David Ruhnken, among others, enabled Leiden to maintain its reputation for excellence down to the end of the 18th century. At the end of the nineteenth century, Leiden University again became one of Europe's leading universities. At the world’s first university low-temperature laboratory, professor Heike Kamerlingh Onnes achieved temperatures of only one degree above absolute zero of −273 degrees Celsius. In 1908 he was also the first to succeed in liquifying helium and can be credited with the discovery of the superconductivity in metals. The
Heike Kemmer breeding stable for Hanoverian horses now run by Heike. In the 1990s, Heike became the farm manager, and moved the focus of the stables from show jumping to dressage. Kemmer attended her first Olympics in 2000, as an alternate to the German team, but did not participate in the Games. In 2004, she rode in the Olympics for the first time, placing 26th individually. She also rode as part of the gold-medal winning German team, but as the lowest-scoring member, her score was not used to determine the team's standing. At the 2008 Summer Olympics, her performance improved significantly, and