Charles Townes told me that once, long ago, he was sharing his idea for the laser with John von Neumann and that von Neumann told him his idea wouldn’t work. “What did you think about that?” I asked Townes. “If you’re going to do anything new,” he said, “you have to disregard criticism. Most people are against new ideas. They think, ‘If I didn’t think of it, it won’t work.’ Inevitably, people doubt you. You persevere anyway. That’s what you do.” And that was exactly what Charles Townes did. The laser is considered one of the most significant scientific inventions of the modern world.