'Amateur' is not a term that's always considered as a compliment, but it should be, argue amateur scientists. The word amateur comes from the French 'amour', meaning someone who loves what they do. At one stage in the past, nearly all scientists were amateurs. Quentin Cooper looks into the continuing role of enthusiasts at the front line of research. He is joined by Dr Adam Rutherford from the journal Nature, Professor Rob Fuller, who co-ordinates the work of 30,000 volunteers for the British Trust for Ornithology, prize-winning young scientist Hannah Stuart, and founder President of the Society for Amateur Scientists in the USA, Dr Shawn Carlson. He also visits the garden observatory of Tom Boles, who monitors 12,000 galaxies for exploding stars from his home in Suffolk.