Experimenters Alexander, Billie and Marianna visit Nina in her workshop and discover what a cantilever is, and what happens when you put weight on a long cantilever. Next, they visit the Forth Bridge and find out how long cantilevers stay up. Finally, they have a go at being a bridge themselves to explain how they hold up heavy weights, like trains.

Originally released by BBC, 2015. Streaming video file encoded with permission for digital streaming by Infobase on January 17, 2017.

Meet the Neurons (0:55); --How Does a Bridge Work? (2:16); -- Senses Experiment (2:23); -- Beams Support Long Cantilever (3:47); -- Human Cantilever Experiment (1:59); -- Summary: How Does a Bridge Work? (0:35); -- Credits: Bridges—Nina & the Neurons: Get Building (1:57);.