For all their variety and variation, cities are, at their root, physical systems. That means, at some fundamental level, they are also expressions of the laws of physics. In physics size matters (or "scale" as we call it). Physicists learn different things about an object by looking at it from different scales. In our first exploration of physics and cities we stayed at the street level. At that scale we saw cities as machines: cars and elevators, pipes and plumbing. Then we went up to the roof. At that scale we saw cities as engines, vast systems for turning energy into work.
Saying that the global economic recovery "has suffered new setbacks, and uncertainty weighs heavily on the outlook," the International Monetary Fund today warned that the probability of "recession in advanced economies and a serious slowdown in emerging market and developing economies" next year have gone up.
The fund said its research indicates the risk of those things occurring in 2013 "has risen to about 17 percent, up from about 4 percent in April 2012."
Good morning. I'm Renee Montagne. Planning a wedding can feel like running a marathon. A couple in Oregon took that metaphor a step further and married while running one. The bride wore white. Her veil attached to a baseball cap. The groom a tuxedo T-shirt. It was a race that sparked their romance. So Eric Johansson and Katie Holmes decided to run 20 miles of the Portland marathon before stopping at a park to exchange vows. Then the newlyweds ran the final 6.2 miles. It's MORNING EDITION. Transcript provided by NPR, Copyright NPR.