Not sure where to post this. You can move it if you like. There is no right answer to this but I hope it makes you think as much as it made me think. A long time in the future, man-kind can travel backwards in time by breaking the light barrier. The research team calculate that according to Einstien's equations, they will trace a smooth path through space-time as they are travelling backwards through time. The same set of events can be viewed form inside and outside the ship. They are however, curious as to what happens if they drop one of the glasses of champaign aboad. According to the 2nd law of thermodynamics, the glass drops then smashes as time goes forward. This gives rise to a simple paradox. Which way is forwards? If the second law is obeyed in the reference frame of the space ship, the on-board team experience nothing unusual, but the rest of the team on the ground will see the same events, but to them, the glass is smashing, then rising from the floor! Events aboard seem to go backwards from the reference frame of the GROUND team. To correct the paradox, the ground team argue that the second law must be obeyed in the reference frame of the ground team, now they would see it the right way round. BUT the on-board team complain that they would experience the glass smashing, then rising from the floor as they travel backwards through time! Events aboard seem to go backwards from the reference frame of the ON-BOARD team. Only one can be correct. The two teams place a bet. Who wins and why?