By 2020, 70 percent of the world’s population will live in cities, says Professor Marta González. She hopes to improve urban livability, transportation and energy networks through her study of human mobility via cellphone data. “Cellphones are the neurons of a truly global nervous system of the global communications network,” said González, whose work is currently being tested in transportation systems and logistics planning in Rio de Janeiro, as the city prepares to host the 2014 World Soccer Cup.