Fifty Years of Plate Tectonics: Afterthoughts of a Witness

I suggest that the Earth Sciences in the mid‐1950s entered a state of supercooling where the smallest input could lead to the simultaneous crystallization of new ideas. In 1959, I joined the Lamont Geological Observatory, one of the hotbeds where the Plate Tectonic revolution germinated. This paper is not an exhaustive history from an unbiased outside observer. It is a report of one of the participants who interacted with quite a few of the main actors of this revolution and who, 50 years later, revisits these extraordinary times. I emphasize the state of confusion and contradiction but also of extraordinary excitement in which we, earth scientists, lived at this time. I will identify several cases of what I consider to be simultaneous appearances of new ideas and will describe what now appear to be incomprehensible failures to jump on apparently obvious conclusions, based on my own experience. Key Points The Earth Sciences in the mid‐1950s entered a state of supercooling where the smallest input could lead to the simultaneous crystallization of new ideas I emphasize the state of confusion and contradiction and also of extraordinary excitement in which we, earth scientists, lived at this time