Albert Einstein was a German mathematician and physicist who developed the special and general theories of relativity. In 1921, he won the Nobel Prize for physics for his explanation of the photoelectric effect. In the following decade, he immigrated to the U.S. after being targeted by the Nazis. His work also had a major impact on the development of atomic energy. In his later years, Einstein focused on unified field theory. With his passion for inquiry, Einstein is generally considered the most influential physicist of the 20th century. A particle physicist, Martin Counihan (University of Southampton) is responsible for continuing education and public outreach in the sciences. He has provided hundreds of courses, initiating and directing programmes not only in physics but also in environmental science, information technology, and the humanities. He is part of the School of Physics and Astronomy and now on attachment to the Faculty of Engineering, Science and Mathematics, providing the interdisciplinary course 'Science in History'. Professor Marika Taylor (Series Foreword) is a Professor of Theoretical Physics and Head of School within Mathematical Sciences at the University of Southampton. Her research interests include all aspects of string theory, gravitational physics and quantum field theory. In recent years much of her work has been focused on holographic dualities and their implications. Marika's research has featured in such publications as Physical Review, Journal of High Energy Physics and General Relativity and Gravitation among others.