The Earth's continents are in constant motion. On at least three occasions, they have all collided to form one giant continent. If history is a guide, the current continents will coalesce once again to form another supercontinent. And a study in Nature now shows how that could come about.
You can think of continents as giant puzzle pieces shuffling around the Earth. When they drift apart, mighty oceans form. When they come together, oceans disappear. And it's all because continents sit on moving plates of the Earth's crust.
Republican presidential candidate Mitt Romney's losses on Tuesday, while not very meaningful in the race to accumulate delegates, have raised questions once again about his ability to inspire passion from his party's base and about his viability in the general election.
Rival Rick Santorum's victories in Colorado, Missouri and Minnesota dealt a setback, if not exactly a body blow, to Romney — whom Santorum routinely dismisses as a candidate with a big machine but no core.
Ask Detroit teachers about their biggest challenge and many will say, "You can't teach kids who don't come to class." Last year, the average Detroit public high school student missed at least 28 days of school.
Now, as part of its effort to get parents more involved, the district has launched a major initiative to improve attendance. The effort includes parent workshops and attendance agents charged with pushing parents to send their kids to school every day.
Mother and calf common dolphins are transported to the beach by a team from the International Fund for Animal Welfare and the New England Aquarium before being released back into Cape Cod Bay on Jan. 14. So far, area rescuers have counted 147 dolphin strandings this winter alone.
Dolphins have been stranding themselves along the shores of Cape Cod, Mass., since the Pilgrims' times, and this winter is no different. What is different is how long the latest round of strandings has lasted — almost a month. So far, rescuers have counted 147 strandings and 38 successful rescues and releases.
Russian feminist collective Pussy Riot stages a protest in Moscow's Red Square against Prime Minister Vladimir Putin. Members were arrested and detained briefly after their mid-January protest.
Credit Pussy Riot
"Kot" (left) and "Schumacher," members of the feminist collective, say their group will be staging more illegal anti-government performances around Moscow in the weeks leading up to the March 4 presidential elections. They say they were galvanized originally by their opposition to government policies against women.
Anti-government protests in Russia are taking many different forms, from mass rallies and marches to defiant street art and music.
Just recently, members of a feminist punk group were arrested in Moscow's Red Square after they performed a song ridiculing Prime Minister Vladimir Putin. The group, which calls itself Pussy Riot, says it's planning more stunts before March's presidential elections.
A Mitt Romney supporter holds up a sign showing her love for Romney and Denver Broncos quarterback Tim Tebow at a rally for the GOP presidential candidate at Arapahoe High School this week in Centennial, Colo.
A path through farmland leads to the ocean in Loleta, Humboldt County, Calif.
Credit Lisa Hamilton / Real Rural
Jose Ruiz Dionicio came to the San Joaquin Valley from his village in Peru in 2009 on a four-year contract. "Having herded sheep in the Andes, he was recruited to do similar work here, though herding with trucks and trailers is new to him," writes Hamilton.
Credit Lisa Hamilton / Real Rural
Daniel (left) and Wyatt, County Fair, Boonville, Mendocino County
Most moms probably don't want their babies around pot growers, but San Francisco-based writer-photographer Lisa Hamilton is totally cool with it.
In fact, her baby, Ada, is a little over a year old and has probably already seen more of California than most Californians. And that, to Hamilton, is a problem.
For her, the basic issue is exemplified by something like this: We can see what a stranger in Japan is having for lunch on Instagram. But we can't so easily see where that lunch came from, or who harvested the ingredients.