ARROW IN THE BLUE (ARTHUR KOESTLER) AND SPEED IN INERTIAL FRAMES OF REFERENCE

The content of the chapter I was reading is as follows: As the cannon-ball carrying the explorers towards the moon travel through the space, one of the animals aboard, a little fox-terrier, dies. After some hesitasion the explorers decide to throw the corpse out through the air-tighy hatch. This is don; and then the passengers, looking through the thick glass window, realise to their horror that the body of the dog is flying on a course parallel to their own through the space. They thought it would drop away, but the carcass share the momentum of the cannon-ball, just as an object thrown from the window of a moving railway carriage, shares the momentum of the train; and outside teh aerth´s atmosphere there is no friction to act as a brake. Gradually the carcass increases its distance from the window, impelled by the persistence of the gentle thrust which had sent it through the hatch; but though slowy receding, it maintains its parallel speed and keeps abreast of the window. The dead fox-terrier has become a planet or a meteor which will continue to travel in its dark elliptic orbit round the earth through eternity

In this text, Koestler himself makes my job on this post, since he comments a play by Verne from a scientific point of view. Koestler´s autobiography is highly recommendable as a very good way to approach XXth century thanks to his presence in every important fact of the century.
I read these memoirs when I was younger and I used to tell my brother about his adventures in our shared bedroom, even a mystical experience happened in Seville´s prison. My brother used to call him a show-off, as he thought it was impossible that kind of things to be true. But don´t worry, I´m not going to spoil the end of the book and neither the end of Koestler´s life