“There are 10^11 stars in the galaxy. That used to be a huge number. But it's only a hundred billion. It's less than the national deficit! We used to call them astronomical numbers. Now we should call them economical numbers.”
Richard Feynman, who would turn 97 years old today. Happy birthday, mr. Feynman!
Sometimes I write stuff here not because I know things, but rather, because I would like to know more, and I think the audience of this blog may help me find the material I need to become more knowledgeable on some topic. Having a blog is a privilege, in the sense that the one-to-many communication it establishes between the writer and the readers allows the owner to sometimes have access to the (all together vast) knowledge of his or her readers. Thanks to you, dear reader, to your comments, reactions, and suggestions expressed in the comments thread, I learn more on topics I do not have an expertise on. I cherish this one-to-many communcation means and I am grateful to you for it.
As yesterday in Italy was the equivalent of Labor Day, and today is a Saturday, with people around me exploiting the three-day rest for a recreational trip, I do not feel in a very productive mood, so rather than writing something original here I will exploit other people's work, pointing at what I found interesting or anyway worth my attention among the papers appeared on the Cornell Arxiv in the last few days, and other assorted material.