On May 19 2009 the Space Shuttle Atlantis released the Hubble Space Telescope back into orbit after a hugely successful servicing mission. To mark the occasion, Mario Livio, one of the scientists involved in the mission and intimately acquainted with Hubble, takes stock of its scientific legacy.
The mathematical maps in theoretical physics have been highly successful in guiding our understanding of the universe at the largest and smallest scales. Linking these two scales together is one of the golden goals of theoretical physics. But, at the very edges of our understanding of these fields, one of the most controversial areas of physics lies where these maps merge: the cosmological constant problem.