> However, when any of the starships behind him crosses the horizon, the captain of that starship will see Bob in front of them, also crossing the horizon! Thi

> However, when any of the starships behind him crosses the horizon, the captain of that starship will see Bob in front of them, also crossing the horizon! This is a tricky point. The 51-st captain will see the ships in front of him getting slower and slower, the distance between them growing less and less. At the horizon, they'll be separated by zero distance. But how can that be? Imagine that you're looking at a line of cars in front of you, while sitting in a bus. You can see far ahead, and you can project the distances between cars onto your windshield. Now you go out of the bus and look at the cars ahead of you again from your regular height. Now you get down on your knees, and look again. And then lie down on the road and look ahead again. That's exactly how it would feel for that captain, any lateral distances between ships will keep getting smaller and smaller, until they completely disappear at the horizon. All the ships in front of you will be squished into a line, and the ship in front of you would block the view.