Hair ice probably isn't what you think, but something much stranger. It's basically a type of ice that forms on dead wood and takes the shape of fine, silky hair. Meteorologist and discoverer of continental drift, Alfred Wegener, described hair ice on wet dead wood in 1918, assuming some specific fungi as the catalyst, a theory mostly confirmed by Gerhart Wagner and Christian Matzler in 2005. They can maintain their shape for hours and sometimes days. This long lifetime indicates that something is preventing the small ice crystals from recrystallizing into larger ones, since recrystallization normally occurs very quickly at temperatures near 0°C. Continue reading for more.