This is a demo of what heppens when you mix an acid (ethanoic acid or vinegar) and a base (sodium hydrogen carbonate or baking powder). You get a salt (sodium accetate) plus carbon dioxide gas (the fun bit) and water (the boring bit).

In this, the first Dr Campbell's Science Demo, Dr C will be demonstrating to us something that Galileo showed almost 400 years ago. The law of gravity...