Essay: the tau lepton and thirty years of changes in elementary particle physics research

Starting with the 1975 discovery of the tau lepton, I look back on the last three decades of change in the substance and style of experimental and theoretical research in elementary particle physics. I recount the major accomplishments of those decades and predict a bright future for particle physics in the next two decades. Turning to three problems, I lament the change in theoretical style and taste, I discuss the growth in the complexity, size, and cost of particle physics experiments, and I conclude with a pessimistic comment on the size of particle physics collaborations.