Our curator of public life discusses 19th-century medicine with host Mo Rocca, who also shows us how AR is helping surgeons see inside their patients, the doorway roller easing backaches, and a status report on previously featured innovators.

The director of Greenfield Village discusses baseball's beginnings with host Mo Rocca, who also shows us dry dock boat storage that works like a vending machine, the heads-up display showing pilots what's behind the clouds, and the device measuring the air in your lungs.