This undated photo was taken of John Hinckley Jr. in front of the White House. He attempted to assassinate President Ronald Reagan in D.C. on March 30, 1981. AFP/AFP/Getty Images hide caption

toggle caption AFP/AFP/Getty Images

A typical Native American oyster deposit, or midden, dating to about 1,000 years ago. Archaeologists are finding clues to sustainable oysters harvesting in these remains. Torben Rick/Smithsonian Institution hide caption

toggle caption Torben Rick/Smithsonian Institution

"There is plenty of room at the bottom": An excerpt from a landmark 1959 lecture by physicist Richard Feynman is written on a sheet of copper with chlorine atoms. Otte Lab/Delft University of Technology hide caption

toggle caption Otte Lab/Delft University of Technology

President Obama and Hillary Clinton stand together on stage on the third day of the Democratic National Convention in Philadelphia. Justin Sullivan/Getty Images hide caption

toggle caption Justin Sullivan/Getty Images

Women often save up questions for an annual office visit that they think don't warrant a sick visit to the doctor during the year, research finds. Tim Pannell/Fuse/Getty Images hide caption

toggle caption Tim Pannell/Fuse/Getty Images

Clinton was the first student to deliver a commencement speech at Wellesley College in 1969. Her criticism of Sen. Edward Brooke's speech received national attention. John M. Hurley/Boston Globe via Getty Images hide caption

toggle caption John M. Hurley/Boston Globe via Getty Images

Taking On A U.S. Senator As A Student Propelled Clinton Into The Spotlight

  • Download
  • <iframe src="https://www.npr.org/player/embed/486799201/487741266" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

Hillary Clinton joins President Obama onstage after he delivers his speech at the Democratic National Convention on Wednesday. Aaron P. Bernstein/Getty Images hide caption

toggle caption Aaron P. Bernstein/Getty Images

Sen. Tim Kaine spoke Spanish at a rally earlier this month in Miami, where he was announced as Hillary Clinton's vice presidential running mate. Gustavo Caballero/Getty Images hide caption

toggle caption Gustavo Caballero/Getty Images

Clinton Campaign Says Trump Is Encouraging 'Espionage' After Hacking Comment

  • Download
  • <iframe src="https://www.npr.org/player/embed/487665642/487665643" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

In 2004 Reid Brewer of the University of Alaska Southeast measured an unusual beaked whale that turned up dead in Alaska's Aleutian Islands. A tissue sample from the carcass later showed that the whale was one of the newly identified species. Don Graves hide caption

toggle caption Don Graves

Chief David Beautiful Bald Eagle during the opening of the Days of '76 Museum in Deadwood, S.D. Bald Eagle died on Friday at the age of 97. Tom Griffith/Rapid City Journal via AP hide caption

toggle caption Tom Griffith/Rapid City Journal via AP

David Bald Eagle, Lakota Chief, Musician, Cowboy And Actor, Dies At 97

  • Download
  • <iframe src="https://www.npr.org/player/embed/487651658/487815116" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">

Democratic vice presidential nominee Tim Kaine does a walk on the Democratic National Convention stage ahead of his prime time speech on Wednesday night. Jessica Kourkounis/Getty Images hide caption

toggle caption Jessica Kourkounis/Getty Images

How Tim Kaine Went From City Council To Vice Presidential Candidate

  • Download
  • <iframe src="https://www.npr.org/player/embed/487665600/487665601" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

Memorial Hermann Hospital System in Houston was one of very few nationally renowned hospitals to get a five-star ranking from Medicare. Ed Uthman/Flickr hide caption

toggle caption Ed Uthman/Flickr

Once scientists grew these Staphylococcus lugdunensis bacteria in a lab dish, they were able to isolate a compound that's lethal to another strain commonly found in the nose that can make us sick — Staphylococcus aureus. Mostly Harmless/Flickr hide caption

toggle caption Mostly Harmless/Flickr

'Nose-y' Bacteria Could Yield A New Way To Fight Infection

  • Download
  • <iframe src="https://www.npr.org/player/embed/487529338/487774066" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">

Vice President Joe Biden talks to students from Eagle Academy for Young Men during a walk at the Democratic National Convention on Tuesday. He will speak Wednesday night. Jessica Kourkounis/Getty Images hide caption

toggle caption Jessica Kourkounis/Getty Images