John Tyndall (1820-1893), An Irish physicist working in England,, made numerous discoveries and measurements on heat radiation and a variety of other topics, and was also a noted science popularizer. He became interested in the ice ages from his studies of glaciers in the Alps (a pioneer alpinist, he made the first ascent of the Weisshorn). It was while pursuing the cause of ice ages that he discovered that water vapor, methane and carbon dioxide absorb infrared radiation.