Talk of the Nation

Three weeks after 17-year-old Trayvon Martin was shot and killed by neighborhood watch volunteer George Zimmerman, no arrests have been made in what critics are calling a case of racial profiling. Columnist Leonard Pitts says the incident exposes society's "blindness" to African-Americans.

Former Rutgers student Dharun Ravi could face 10 years in prison and deportation to his native India after being convicted of bias intimidation. Ravi used a webcam to spy on his roommate, Tyler Clementi, having an intimate encounter with another man. Clementi killed himself several days later.

Business and political leaders have repeatedly warned that America's scientists and engineers are in short supply. However, some economists say the numbers indicate the opposite — a glut of high-tech workers. A panel of experts debate whether America's schools produce the scientific workforce needed to compete globally.

On his upcoming trip to Mount Everest, mountaineer Conrad Anker will team up with geologist Dave Lageson to remeasure the peak's exact altitude--a stat scientists still dispute. Physiologist Bryan Taylor will also be in Nepal to monitor how Anker's blood, brain and muscles respond to the thin Himalayan air.

Estimated altitude for this flight was about 115,000 feet, says Raul Oaida, 18-years-old. Raul launched the shuttle, along with a video camera and a GPS tracker, by way of a large helium balloon. Flight time was about three hours--the shuttle landing about 150 miles south of where it took off.