Eric Walker added The U.S. Is Getting Shorter, as Mapmakers Race to Keep Up - The New York Times to Colorado, Geophysics and Articles in the New York Times

Eric Walker added The U.S. Is Getting Shorter, as Mapmakers Race to Keep Up - The New York Times to Geophysics, and added Geophysics to Physics

Eric Walker added a number of topics and a number of links to Physics, and added Physics to Science, engineering, mathematics and the humanities