An outbreak of green algae, or hutai in Chinese, has invaded the seawaters off eastern Shandong. It looks harmless and lots of fun, as beachgoers are pictured frolicking in the green mass. But...

Every day, millions of people check in on Foursquare. We took a year's worth of check-ins in London, Chicago and Istanbul and plotted them on a map. Each dot represents a single check-in, while the...