Plot: We all know tides have something to do with gravity from the Moon and Sun, but if gravity affects the motion of all objects equally, then how come oceans have large tides while other bodies of water don't? It's because your mental picture of the tides is probably WRONG!!! Join Gabe on this week’s episode of PBS Space Time as he sets the record straight on tidal force, gravitational differential and what role the moon actually plays in tides. Why don't lakes have tides? Watch the episode to find out!