The 2nd century AD author Lucian wrote that during the Siege of Syracuse Archimedes destroyed enemy ships with fire. The device, sometimes called the "Archimedes heat ray", was used to focus sunlight onto approaching ships, causing them to catch fire. This weapon has been the subject of ongoing debate about its credibility since the Renaissance. It has been suggested that a large array of highly polished bronze or copper shields acting as mirrors could have been employed to focus sunlight onto a ship. This would have used the principle of the parabolic reflector in a manner similar to a solar furnace. Archimedes of Syracuse (287-212 BC) was a Greek mathematician, physicist, engineer, inventor, and astronomer. Few details of his life are known, but he is regarded as one of the leading scientists in classical antiquity. Among his advances in physics are the foundations of hydrostatics, statics and an explanation of the principle of the lever. He is credited with designing innovative machines, including siege engines and the screw pump that bears his name. Archimedes is considered to be the greatest mathematician of antiquity and one of the greatest of all time.