Telescope earliest existing record of a telescope was a 1608 patent submitted to the government in the Netherlands by Middelburg spectacle maker Hans Lippershey for a refracting telescope. The actual inventor is unknown but word of it spread through Europe. [[Galileo Galilei|Galileo]] heard about it and, in 1609, built his own version, and made his telescopic observations of celestial objects. The idea that the [[Objective (optics)|objective]], or light-gathering element, could be a mirror instead of a lens was being investigated soon after the invention of the refracting telescope. The potential advantages of using [[parabolic reflector|parabolic mirrors]]—reduction of [[spherical aberration]] and no
Water supply and sanitation in the Netherlands Research Institute. According to the Netherlands Water Information Network, the Netherlands has “developed a coherent knowledge infrastructure in the water sector, comprising government and private research centres, technological and educational institutes (such as Alterra, UNESCO-IHE, ITC, Deltares) and several universities”. These institutes carry out a broad range of basic and applied research, from hydraulic engineering to integrated water management. The institutes have formed close connections with internationally oriented private sector companies. The institutes “have built up considerable networks and experience in water-related issues at international level”. Lessons learned abroad have also been successfully applied in the Netherlands. For example, the