After the link to TED was posted a few threads below, I began to browse through the videos and I found this one which I liked a lot. http://www.youtube.com/watch?v=5hJCxSiH4ts&feature=channel_page I got questions 1 and 2 right. But the 3rd and 4th questions wrong and along the lines of the misconceptions he was referring to. I understood 4 myself but his explanation for 3 was a bit brief and I'm not sure I got it. Could someone explain the answer to Q3?