In 1998, Danish physicist Lene Vestergaard Hau led a combined team from Harvard University and the Rowland Institute for Science which succeeded in slowing a beam of light to about 17 meters per second, and researchers at UC Berkeley slowed the speed of light traveling through a semiconductor to 9.7 kilometers per second in 2004. Hau and her colleagues later succeeded in stopping light completely, and developed methods by which it can be stopped and later restarted. This was in an effort to develop computers that will use only a fraction of the energy of today's machines.