John Cromwell Mather is an American astrophysicist, cosmologist, and Nobel Prize in Physics laureate for his work on the Cosmic Background Explorer Satellite (COBE) with George Smoot.This work helped cement the big-bang theory of the universe. According to the Nobel Prize committee, "the COBE-project can also be regarded as the starting point for cosmology as a precision science."Mather is a senior astrophysicist at the NASA Goddard Space Flight Center (GSFC) in Maryland and adjunct professor of physics at the University of Maryland College of Computer, Mathematical, and Natural Sciences. In 2007, Time magazine listed Mather among the 100 Most Influential People in The World. In October 2012, he was listed again by Time magazine in a special issue on New Space Discoveries as one of the 25 most influential people in space.Mather is one of the 20 American recipients of the Nobel Prize in Physics to sign a letter addressed to President George W. Bush in May 2008, urging him to "reverse the damage done to basic science research in the Fiscal Year 2008 Omnibus Appropriations Bill" by requesting additional emergency funding for the Department of Energy's Office of Science, the National Science Foundation, and the National Institute of Standards and Technology.Mather is also the senior project scientist for the James Webb Space Telescope (JWST), a space telescope launched to Lagrange point L2 on December 25, 2021.In 2014, Mather delivered an address on the James Webb Space Telescope at the second Starmus Festival in the Canary Islands.