Book excerpt: "Revenge of the Tipping Point" by Malcolm Gladwell
50 "exceptionally well-preserved" Viking skeletons unearthed in Denmark
New species of "ghost shark" discovered living deep in the Pacific Ocean
Hurricane John intensifies suddenly, slams into Mexican tourist hotspots
"Doomsday Glacier" set to retreat "further and faster," scientists warn
Earth will get a second moon for nearly 57 days this year
When and how to see September's Harvest Moon
Mysterious 9-day seismic event triggered by 650-foot tsunami
