"Billy was working on the second letter when the first letter was published. The second letter started out like this:
"The most important thing I learned on Tralfamadore was that when a person dies, he only appears to die. He is still very much alive in the past, so it is very silly for people to cry at his funeral. All moments, past present and future always have existed, always will exist. The Tralfamadorians can look at all the different moments like we can look at the stretch of the Rocky Mountains, for instance. They can see how permanent all those moments are, and they can look at any moment that interests them. It is an illusion that we have here on Earth that one moment follows another, like beads on a string, that once a moment is gone it is gone forever
When a Tralfamadorian sees a corpse, all he thinks is that the dead person is in a bad condition in that particular moment, but that the same person is just fine in plenty of other moments. Now, when i myself hear that somebody is dead, I simply shrug and sat what the Tralfamadorosns say about dead people, which is, 'So it goes.' ""

Kurt Vonnegut - SlaughterHouse-Five