Paul C W Davies Editor

Sara Imari Walker is a theoretical physicist and astrobiologist. She is an Assistant Professor in the Beyond Center for Fundamental Concepts in Science in the School of Earth and Space Exploration, Arizona State University. She is also a Fellow of the Arizona State University-Santa Fe Institute Center for Biosocial Complex Systems, co-founder of the astrobiology-themed social website SAGANet.org, and is a member of the Board of Directors of Blue Marble Space. She is active in public engagement in science, with recent appearances on 'Through the Wormhole' and NPR's Science Friday. Paul C. W. Davies is Regents' Professor and Director of the Beyond Center for Fundamental Concepts in Science at Arizona State University. He is a theoretical physicist, cosmologist and astrobiologist. He has written 30 books, many for the general public. In 1995 he was awarded the Templeton Prize for his work on the deeper meaning of science. He was also awarded the Faraday Prize by the Royal Society, the Kelvin Medal by the Institute of Physics, the Robinson Cosmology Prize, and three honorary degrees. In 2007 he was named a Member of the Order of Australia in the Queen's birthday honours list and in 2011 he received the Bicentenary Medal of Chile. The asteroid 1992 OG was renamed (6870) Pauldavies. George F. R. Ellis, FRS, is Professor Emeritus of Applied Mathematics at the University of Cape Town. He is a relativist and cosmologist who has worked on exact and perturbed cosmological models in general relativity theory and carefully studied observational limits in cosmology. He wrote The Large Scale Structure of Space Time with Steven Hawking. His more recent research relates to the philosophy of cosmology and the emergence of complexity. He has various honorary degrees, and was awarded the Star of South Africa Medal by President Nelson Mandela in 1999 and the Templeton Prize in 2004.