Start a fire with ice? That's easy. Just make a collecting | Physics

Start a fire with ice?

That's easy.

Just make a collecting lens out of a piece of ice in which the central part is thicker than the periphery.

Fire making with lenses is based on the fact that the sun's rays and the heat energy they carry are concentrated in one point due to the refraction of the light by the walls of the lens. If a flammable rubbish is placed at this point, it will quickly heat up and begin to smolder.