Backgammon

Operation Desert Rock was the codename for a series of military tests in the 1950s aimed at understanding the effects of atomic radiation on ground troops. In total, over 50,000 U.S. soldiers were exposed to 69 radioactive blasts

These Atomic Bomb Tests Used U.S. Troops as Guinea Pigs (3:29)

Gasp! The answer will amaze you.

Ask Smithsonian: How Long Can a Person Hold Their Breath? (1:32)

A giant killer hornet war is waged between two colonies, and the resources, territories, and survival of a new generation are at stake. Watch the battle unfold as these huge hornets risk their lives for their kingdoms.

Two Giant Killer Hornet Colonies Battle to the Death (3:25)

In this exclusive clip from the 1930s, Confederate veterans step up to the mic and let out their version of the fearsome rallying cry

What Did the Rebel Yell Sound Like? (4:22)