A look at sodium street lights. Featuring Dr Meghan Gray. UV Light: https://youtu.be/u8xx-cfzAeA Hydrogen Alpha: https://youtu.be/CH880_VrxxU Visit our website at http://www.sixtysymbols.com/ We're on Facebook at http://www.facebook.com/sixtysymbols And Twitter at http://twitter.com/sixtysymbols This project features scientists from The University of Nottingham http://bit.ly/NottsPhysics Sixty Symbols videos by Brady Haran http://www.bradyharanblog.com Email list: http://eepurl.com/YdjL9