https://xkcd.com/2011/ https://xkcd.com/2011/ - so ignoring the sarcasm in the comic, the two red lines are "throwing a ball" like you are used to - and the bla

https://xkcd.com/2011/ https://xkcd.com/2011/ - so ignoring the sarcasm in the comic, the two red lines are "throwing a ball" like you are used to - and the black line is the ball that never quite reaches the ground - i.e. the ISS.