Archimedes lived and worked in Sicily in the third century BC, and can be considered the first person to think like a physicist. Like other early scientists he did not specialise and was known for his mathematical proofs, ship design and inventions as well as his work on the principles underlying basic devices such as the pulley and the lever.
His most famous discovery was of the principle of buoyancy, which lent its name to the "Eureka" moment. Archimedes is considered to be the founder of the science of forces.
As a military adviser to King Hieronymus, Archimedes designed the huge offensive and defensive war machines used when the Romans besieged Syracuse, during the Punic Wars.
You could say that Archimedes was simply doing his civic duty – helping to defend his homeland against invaders.
But did he cross a moral line, when he invented offensive weapons?