Salt is one of those dangerously tasty substances. We add the magical crystals of sodium chloride to almost everything that we cook or bake, and according to many public health experts, we add too much.
They want us to cut back, to lower our risk of heart attacks or strokes.
Yet when you really start looking for ways to do this, you run into a paradox and a scientific puzzle.
First, the paradox. Too much salt may kill us, but our bodies need some of it to survive.
Friday is the last day of a 5,125-year cycle in the Mayan calendar, sparking talk about the possible end of the world. About two years ago, a rumor began circulating on the Internet that the French village of Bugarach, population 200, would be the only place to survive this apocalypse.
But despite many news stories of people flocking to the village, less than two weeks before "doomsday," there was no one on the streets. Houses were shuttered against the cold.
Tourists are seen in front of the "Gran Jaguar" Mayan temple at the Tikal archaeological site in Guatemala, where ceremonies will be held to celebrate the end of the Mayan cycle known as Baktun 13 and the start of the new Maya Era on December 21.
It is Dec. 20, 2012 — and citizens of Earth are panicking, consumed by the idea that the world will end Friday, something they say was predicted by Mayan astronomers. Of course, most people are not panicking, and Maya expert David Stuart says no one should. The calendar, he says, has plenty of room to go.
As the holiday travel season approaches, the Federal Aviation Administration is under pressure to allow more widespread use of e-readers on commercial flights.
Passengers can now use devices such as Kindles, iPads and Nooks while in flight, but not during takeoffs and landings. The FAA says it is studying the matter, but the chairman of the Federal Communications Commission and a U.S. senator say it's time to act.