Talk of the Nation

In her newest book "Girls Get Curves: Geometry Take Shape" actress and math education advocate Danica McKellar teaches readers geometry, using her signature "girly" style. McKellar discusses the book, and tells why she chose to pair geometry lessons with tips for exercise and eating.

Writing in the journal Nature this week, astronomers say they've found a massive galaxy cluster that's pumping out stars at a record pace. Astronomer Michael McDonald describes the finding, and explains what might be causing the "Phoenix Cluster" to be in celestial overdrive.

A new study claims people with blood type A, B or AB may have a slightly higher risk of heart disease, compared to those with the most common blood group, type O. But some doctors, like cardiologist Eric Topol, question the study's conclusion, and say patients shouldn't fret about their blood type.

Oksana Marafioti spent her childhood touring the Soviet Union with her Romani family, a traveling Gypsy ensemble. At 15, life changed drastically when her family moved to the U.S. In her memoir, American Gypsy, she recounts her journey from the stages of Siberia to a magnet school in Hollywood.

Overall, baby boomers are optimistic about their health and future, according to a 2012 survey by The National Council on Aging, United Health Care and USA Today. But many are unsure about how to pay for long-term care, medical bills and other health costs.

After the Vatican accused the Leadership Conference of Women Religious, America's largest organization of Catholic nuns, of failing to follow Church doctrine on several controversial issues, the group's president suggested they will not backing down.

The Discovery Channel's annual "Shark Week" is one of the longest running events on cable television. After 25 years on the air, it's become an American icon of sorts. "Shark Week" executive producer Brooke Runnette explains how the team keeps the shows exciting year after year.

Eric Nuzum's teen years were scarred by depression, drugs, a brief period of institutionalization and the tragic loss of the one person who helped keep him grounded. In his memoir, Giving Up The Ghost, Nuzum reflects on his troubled past, and the ghosts he continues to hold on to.

The Republican ticket is complete now that Mitt Romney chose Wisconsin congressman Paul Ryan as his running mate. NPR's Ken Rudin and Sergio Bustos, of The Miami Herald, discuss what the Ryan pick means for the presidential race.

According to the Center for Responsive Politics, the 2012 presidential and congressional elections will be the most expensive on record, at an estimated cost of nearly $6 billion. Federal Election Commission Chairman Michael Toner says politicians should spend even more.

On August 14, 2012, the Appalachian Trail turned 75. The more than 2,000 mile path winds through 14 states, from Georgia to Maine, and continues to capture the imagination of hikers from around the world. Along the trail, many hikers discover things they never set out to find.

Books can change the way we think and can influence events long after they have been written. The Library of Congress exhibit "Books That Shaped America" features 88 books — from Thomas Paine's Common Sense to Dr. Seuss' The Cat In The Hat — that have influenced national identity.

The murders of six people at the Sikh temple in Oak Creek, Wis., by a gunman with ties to white supremacists has raised questions about the prevalence and influence of hate groups in America — who they are, what they do, and how they recruit new members.

Army Reserve officer Tammy Smith was promoted to the position of Brigadier General last Friday. In doing so, she became the first gay general to serve openly in the U.S. military. Gen. Smith talks with NPR's Lynn Neary about her career in the military and the significance of her recent promotion.

Many athletes aspire to compete in the Olympic Games. Few ever achieve it. For those who do, what happens when the games are over? Former Olympic swimmer Nancy Hogshead-Makar, who won three gold medals in the 1984 Olympics, talks about her life after her athletic career.