Liz Bonnin, Dallas Campbell, Jem Stansfield and Dr Yan Wong take on more experiments and scientific challenges.
Jem hits the furnace to make steel and discovers how it built the modern world, while Liz investigates whether science can help humans live forever. Dallas turns into a dolphin with the help of the latest US technology, and Yan challenges museum visitors to make fire out of thin air.
Bang Goes the Theory is co-produced with The Open University. For more ways to put science to the test, go to www.bbc.co.uk/bang and follow the links to The Open University.