Refraction!

Sitting at the window in Cafe Nero before church this morning I was very aware of people appearing to be standing in a place where there was no one. I tried to remember what I was told about light in my science class ..... the word refraction sort of popped in to my mind. The group appears to be standing at the top of the lane - in reality they were way to my right along Sauchiehall Street. I couldn't work out how many different paths the light was taking (I'm no physicist!).