Jem straps a race horse to his car to explain what horsepower is, Liz sets Dallas a free diving challenge that leaves him gasping for air, Dr Yan shows shoppers how to burn steel, and Dallas goes to CERN to see how a cosmic tea party created everything in the universe.

The programme 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. Show less