Numerous less publicized models wallop through the science press, on the hope, perhaps, of a lucky strike: For example, not-obviously-promising substances such as hydrogen, ammonia, hydrogen cyanide, formaldehyde, or peptides, possibly kick started life. Maybe metals acted as catalysts. Or mica sheets. Otherwise, cold temperatures or ice helped life get started, despite the fact that cold reduces chemical reaction speed. Or a high salt environment. Or hot springs. No surprise that science writer Colin Barras observes that origin of life is “a highly polarised field of research.” Most fields have only two poles, not twenty. More.