Host Mo Rocca shows us saving homes from floods with an inner tube-like system; the baker using math to create her artistic pies; the French app maker keeping travelers safe by warning of high crime areas to avoid; and, the history of ham radios keeping the world connected.

Host Mo Rocca shows us the startup using drones to deliver lifesaving blood to hard-to-reach villages in Africa; the bed fan that's a hot leg fan; 3D-printed bicycle tires that never go flat; and, how the typewriter changed the history of communication.