Olafur Eliasson, born 1967 in Copenhagen, creates atmospheric installations. My first exposure to his work (exposure pun not intended) was The Weather Project in Tate Modern's Turbine Hall, 2003. No matter your opinions on art installations, on entering a room filled with warm light emitting from a giant sun-like object it's very hard to not feel in awe. Especially when it's influencing a huge crowd to lay down and bathe under it. When joining in you realise it's a mirrored ceiling and a half sun reflected, rather than spoil the illusion it adds mystery. A short video of the installation can be found here. In other works he brings the outside inside with man made environments, often simulating natural phenomenon and uses geometric forms and light to make huge kaleidoscopic structures. My favourite of his works are shown below, to see more visit his website (here).
Photobucket The Weather Project, Turbine Hall 2003 Photobucket One Way Colour Tunnel, 2007 Photobucket Your Watercolour Horizon, 2009