It's the second high-profile American visit this year to North Korea, a country that remains in a state of war with the U.S. It also comes two weeks after North Korea conducted an underground nuclear test in defiance of U.N. bans against atomic and missile activity.

NPR: Dennis Rodman Worms His Way Into North Korea

Europe has just put through the International Atomic Energy Agency a demand that Iran suspend all nuclear activity pending a Nov. 25 meeting on sanctions.

FORBES: Iraq Again?

The discovery of quantum mechanics and Einstein's theory of relativity, vital to much of modern technology and economic activity, including the transistor, the laser and the atomic bomb.

ECONOMIST: Letters

The so-called stress tests will be performed on Europe's 143 working reactors and other atomic installations and will consider a range of factors, including seismic activity, flooding, and power loss at reactors.

BBC: MEPs split over nuclear 'stress tests'

It is believed that China may have been willing to join the new Security Council resolution because satellite surveillance has shown activity at North Korea's nuclear blast test sites suggesting another atomic test may be imminent.

NPR: NKorea Warns It Will Build Up 'Nuclear Deterrence'