If you are in pitch black and you close your eyes, you sometimes can see strange shapes of various colors. A lot of the time these shapes and colors change as you observe them. This phenomenon still occurs if you are not in complete darkness. I am wondering what this is that you are `seeing'? Is...

A week ago, I asked a question on how to invert an axis on spss. Jeromy Anglim moved that question to stackoverflow as it was more suitable to that site, so I made an account there as well so that I could view any answer directly. Today (22-9-2014) there was an inbox message about an answer to my...