Kara and Dalmar explain the science behind polymers. Fill a plastic bag with water, then poke a sharpened pencil through the bag. The water won't leak out due to the stretchy molecules (polymers) sealing the area around the pencil.

Originally released by TV Ontario, 2012. Streaming video file encoded with permission for digital streaming by Infobase on February 17, 2016.

Citizen Science: Water Bag Poke (1:56); .