One of the most important things astronomers do is to spread what we learn through our research to other people: our fellow astronomers, our students, and to the general public. After all, what is the point of learning new things if that knowledge sits in a desk drawer or buried in a computer file? There are stories of physicists who would make a new discovery and go to talk to Nobel-winning physicist Richard Feynman about their discovery. Feynman would listen for a while, dig through a drawer, and find some papers where he had worked out the same problem, and then say that the answer looked right to him. Then he would put his papers away.
If true, these stories are sad. Feynman hated writing papers about his work, but if one of the brilliant minds of physics failed to share his knowledge with the rest of the world, the rest of us lost out on his talent.
On Tuesday, I had the honor of giving a colloquium (an hour-long research talk) here at the University of Texas Astronomy Department. I stood up and talked about my studies of other galaxies and of what we are learning about dark matter in and near those galaxies. The talk went well, and several people contributed new ideas and new viewpoints that will help me look anew at my studies as I go ahead. And I think I gave many people here insight into research that they don't do but that might impact their work. All in all, it was a lot of work but a lot of fun to prepare and give the talk.