Human hair growth
The three stages of hair growth are the anagen, catagen, and telogen phases. Each strand of hair on the human body is at its own stage of development. Once the cycle is complete, it restarts and a new strand of hair begins to form. The rate or speed of hair growth is about 1.25 centimetres or 0.5 inches per month, or about 15 centimetres or 6 inches per year.
Hair ice
Hair ice forms on moist, rotting wood from broadleaf trees when temperatures are slightly under and the air is humid. Each of the smooth, silky hairs has a diameter of about and a length of up to . The hairs are brittle, but take the shape of curls and waves. 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 .