I'm not quite sure where to post this but it certainly isn't homework/coursework so I suppose here is appropriate. The situation is that a friend claims something which I believe to be physically impossible happened, and though it is a minute and pointless point to argue about, I want to explain it to him in a way in which he will understand. The scenario is this: A friend and I were playing table tennis at school, using wooden paddles (this is important as they cannot impart any significant amount of spin onto the ball). During the match, I hit the ball from the back of the table in the centre, give or take a foot, and the ball went back over the net, towards the side which is to "my right". However it clipped the edge the smallest possible amount, and made a tiny sound, whilst continuing its journey down virtually unchecked. Now in table tennis, the rules state that if the ball clips an 'edge', it counts as in, but if it hits the 'side' of the table, it counts as out. (www.allabouttabletennis.com/table-tennis-rules.html for clarification). Whilst my friend acknowledged that it clipped something, he argues that it clipped the 'side' of the table as opposed to the 'edge'. I am trying to explain to him that it isn't possible for a ball which has come from OVER THE SURFACE the table to clip the 'side' without hitting the 'edge': unless of course I put so much sidespin on the ball, that it first traveled outside the constraints of the table and then back in towards it again, clipping the side on the way down... but with a wooden bat, this isn't even conceivable. I was wondering if anyone here would be able to put it in a succinct and convincing way so that I can explain it to him, as it's bugging me that he really doesn't get it. Feel free to use any method of explanation. I have a diagram which can help clarify the situation: img261.imageshack.us/img261/1448/conanni4.jpg (This shows how the ball was struck and explains the problem). www.allabouttabletennis.com/images/table-tennis-table-playing-surface.jpg (This shows the difference between a 'side' and an 'edge').