Sweden is a country with a huge amount of water. It's almost entirely surrounded by sea and has thousands of lakes as well. 11-year-old Jacob lives on the coast and loves sailing his boat on the sea. He often sees large ships sailing past. But how come those large ships don't sink but a stone does? Jacob does all kinds of tests in the water and around it. He discovers that floating and sinking are all about density and upwards pressure. He makes his own lava lamp, gets grapes to dance in lemonade, builds an underwater volcano and discovers that you can sail a short distance in the bathtub. But would you still be able to if you were really heavy?

Originally released by Nederlandse Publieke Omroep, 2014. Streaming video file encoded with permission for digital streaming by Infobase on August 11, 2016.