Talk Of The Nation

In his second inaugural address, the president surprised many listeners by mentioning Stonewall in the same breath as Seneca Falls and Selma — giving the struggle for gay rights the historical weight of the fights for gender and racial equality.

January 2013 marks the 125th birthday of the National Geographic Society. Over the decades, the magazine has transported readers to faraway places, introduced the world to new species and provided a window into a world of exploration and discovery.

Recent unrest in Mali and Algeria point to the growing influence of al-Qaida in North Africa. Wall Street Journal Pentagon reporter Julian Barnes and Ret. Col. Thomas Dempsey, chair for security studies at the Africa Center for Strategic Studies, explain the latest developments and the threat al-Qaida presents in the region.

President Barack Obama faces a number of pressing domestic and foreign policy issues as he begins his second term. A sluggish economy at home, regional conflicts and threats of terrorism abroad and a political stalemate in Washington all pose unique challenges for the president.

As President Barack Obama enters his second term, he leads a country that remains deeply divided on issues from fiscal policy to gun control. Despite the divisions, many Americans maintain a sense of hope for themselves, their towns and the country.

Data scientist Edward Tufte (dubbed the "Galileo of graphics" by BusinessWeek) pioneered the field of data visualization. Tufte discusses what he calls "forever knowledge," and his latest projects: sculpting Richard Feynman's diagrams, and helping people "see without words."

Transcript

FLORA LICHTMAN, HOST:

This is SCIENCE FRIDAY. I'm Flora Lichtman, filling in for Ira Flatow today. Solar wind, geothermal - now there's a new renewable energy source to add to that list. It's free, completely reliable and totally unlimited: the force of gravity. Two British designers have invented a lamp that runs on gravity alone. Their GravityLight - yes, that's its name, aptly named - uses, you guessed it, the pull of gravity on a weight to generate up to 30 minutes of light.

In the Broadway play The Other Place actress Laurie Metcalf ("Jackie" on the TV show "Roseanne") plays a scientist suffering from the dementia she studies. Playwright Sharr White discusses the play and the challenge of presenting complicated science on a theater stage.

In an ongoing crisis in North Africa, the Algerian military has reportedly launched an operation in response to the dozens of hostages taken by extremist groups at a gas field near the Libyan border. NPR's Neal Conan talks with University of Cambridge lecturer George Joffe about the evolving situation.