Whose scientific work first made the Himalayas central to the idea of an active Earth?

Arthur Holmes did not study the Himalayas specifically as a single subject, but his work on radiometric dating helped scientists understand the age of rocks and the long timescales needed for mountain building. Once geologists could date rocks accurately, the Himalayas became a crucial example of an active Earth shaped by plate collision. The mountain range showed that continents are not fixed and that major topography can be created relatively recently in geologic terms. Holmes’s contribution was therefore foundational to modern mountain science.