But I simply couldn't resist this particular headline from the Royal Society's news bulletin. (Not the RS's doing, they simply select science-y headlines & send them round):
Museum asks, what is greatest invention? Science Museum in London choses the steam engine, the X-ray machine, the electric telegraph, the DNA double helix, Stephenson's Rocket train, the Apollo 10 rocket capsule, the Model T Ford car and the Pilot ACE computer.
To me the odd one out is the DNA double helix - it's simply not an invention! The discovery of the structure of DNA is an enormously significant scientific event, but the helix has always been there, so it surely can't be claimed as an invention. (This reminds me of various attempts to patent particular gene sequences. I've never quite been able to understand that one, as the sequences already exist. I guess I'll never make an entrepreneur!)