Using ice as a convex lens can light wood.

yes. Because the convex lens can concentrate sunlight on the upper point, the energy density of this point is very high, which will make flammable wood reach the ignition point and burn.

Ice will melt when it meets the sun. It is doubtful that the ice lens can really concentrate light on the sun and make moxa catch fire. Zheng Fuguang, a scientist in Qing Dynasty, did some experiments by himself according to the record of "Huainan Wanbi Shu", which completely confirmed that ice lens can make fire. He wrote in "The mirror is cold": A tin pot with a slightly concave bottom is filled with boiling water, and the pot is rotated on the ice surface to make a smooth ice lens, which can be used to gather sunlight and ignite paper.

at 12 noon on June 21st, 26, Li Shuangjiang successfully collected the flame of the 4th National Special Olympic Games on Sun Island on the north side of Songhua River in Harbin, aiming at the focus of an ice lens made of Songhua River ice.