Science Journalist K.C. Cole, whose latest book is Mind Over Matter: Conversations with the Cosmos, on spacetime, dark matter, cosmology, the origin and death of the universe. Also: 2 new studies on global warming report catastrophic results; Good news: population growth is slowing; NASA honors fallen astronauts; Scientists have unveiled the fact that there may be thousands of black holes near the center of the Milky Way, as well as a huge black hole at the center.