Which world is the female captain who finally received the text message?

Of course, in the created parallel world, text messages are also sent to the female captain of that parallel world. . . . . Finally, if the time of the captain's death is regarded as reality, he really died in the end. However, because of his attempted terrorist attack, history has changed in the world of source code, so the world where the female subordinate received the text message at the end of the film is the same time and space, which is equivalent to the fact that the captain is still dead in reality. Finally, the source code is equivalent to creating another parallel time and space in the film. Compared with the reality of the captain's death, it is illusory and correct, because the end time and space is also a parallel time and space created by the source code changing history.