Come learn how plate tectonics developed, from the perspective of one who was in on its development from the beginning. The first session will trace how our concepts of Earth's tectonics have changed over the past 60 years, in view of parallel revolutions in transportation, imaging, data collection and analysis, and presentation. The second session will apply concepts from the first session to discuss the geologic history of California. You will benefit from having read John McPhee's book Assembling California before the class.