Laser makes ultra-light mirror out of tiny beads
Laser makes ultra-light mirror out of tiny beads
00:03 18 January 2014 by Jacob Aron
Shooting a laser at polystyrene beads, scientists have made a mirror that is held together by light. The creation could be a step towards putting ultra-light mirrors in space that would be big enough to see continents and forests on planets orbiting far-off stars.
Current space telescopes have limited vision because is it costly and complicated to send large, heavy mirrors into orbit. The mirror on NASA's premiere planet hunter, the Kepler space telescope, is just 1.4 metres across and cannot see planets directly. Instead Kepler spots the tiny changes in brightness when a world crosses in front of its host star.
When NASA's James Webb Space Telescope launches in a few years, it will carry the largest mirror yet into space: a 6.5-metre behemoth made of 18 interlocking segments. To fit into the launch vehicle, the mirror itself will have to be folded up and then unfolded in space.
Jean-Marc Fournier of the Swiss Federal Institute of Technology in Lausanne, Switzerland, and his colleagues have revived an old idea for building much larger mirrors by exploiting the force produced when laser beams hit tiny particles. Previous work has used this force to make optical tweezers, which can trap and manipulate a few particles at a time.
More:
http://www.newscientist.com/article/dn24897-laser-makes-ultralight-mirror-out-of-tiny-beads.html?cmpid=RSS|NSNS|2012-GLOBAL|online-news#.UttSDWfnbmI
