There is a claim that Archimedes recommended the use of well-polished shields to concentrate light from the sun and onto enemy ships, in order to set them alight from afar. But Andy Resnick here says this is a misconception. It may well be a misconception for some of us. But does it work? I reckon that it does, provided a large enough number of shields are accurately pointed onto the sails. And provided the shields are flat like mirrors, not curved. Each shield is like a window through which a 2nd sun shines. If you're just close enough to 100 shields, you can be illuminated by 100 suns, minus losses. If you're twice as far as the limit dictated by the size of the shield and the size of the solar disk in degrees, you need twice the number of shields for the same effect.