The Colladon symposium is a public event that will honor the physicist Jean-Daniel Colladon (1802-1890). He was a scientist born in Geneva and well known for his measurements of the speed of sound in the lake of Geneva, his development of tunnel drilling machines, as well as gas light installations in his home town. However, only few people associate his work also with light guiding and fiber optics. In fact, Colladon demonstrated for the first time in 1841 the guiding of light in a liquid jet of water at the Academy of Science, now the University of Geneva. The Colladon experiment, described 1842 in the French Academy of Sciences' journal “Comptes rendus”, was afterwards reproduced many time and applied in the illumination of water fountains, for example in the Paris World Exposition in 1889. The British physicist John Tyndall performed similar experiments in 1854 at the Royal Institution of Great Britain in London. With his report in the 1854 “Proceedings of the Royal Institution of Great Britain“ he earned the credits for inventing light guiding by total internal reflection. Until today he is mistakenly most often considered as inventor of light guiding in the Anglo-Saxon world. During the symposium four presentations will cover milestones in light guiding: From Colladon's water jet experiments to the fabrication of the first transmission fibers, the invention of the optical amplifier to novel microstructered fibers with bandgap guiding. The 4 topics of the symposium and the speakers are: - Origin of light guiding (Jeff Hecht) - First optical fibers (Donald Keck) - Erbium doped fiber optic amplifiers (David Payne) - Photonic crystal fibers (Philip Russell).