Billy Pilgrim: Is he Really Travelling in Time?

Defenses. We all have them. When in our lives we face things which may be unpleasant or disturbing, we call upon our defenses to guard us from possible harm. They offer us one of many ways we can escape reality which, in so many situations, seems to be working against us. I think that in the case of Billy Pilgrim, time travel is a defense mechanism for this character to escape the trauma he suffered in the war and could not leave behind in Europe once the war had finished. Billy's time travel and encounters with the mysterious creatures he calls the Tralfamadoirans is merely a figment of his imagination.
To absorb the horrifying things he witnessed in the war, I think Billy has created this alternate universe in which he can forget about the things still troubling him from the war and his difficulties in his post war life. The curious aliens, who, as he claims, abducted him and brought him to their planet offer Billy a new perspective on many of the things he struggles to comprehend. The aliens answer some of the questions Billy struggles to answer for himself, including one which is part of one of the most well known parts of the novel when Billy asks a simple, one-word question: "why?"The Tralfamadorians may only be real to Billy Pilgrim, but who is to say that that makes them any less real?
Billy's defenses may seem odd or irrational to us when we read through the novel, but they work for him. They give him a break from the everyday struggle of coping with many past traumatic events. Who are we to judge him for that? Some people, if they knew the different things we did to defend ourselves from our demons, would probably think we were just about as crazy as Billy is, but we're not. It's just our way of dealing with things. Many people, when I try to explain why I do certain things, think I am crazy. Why do I constantly insult myself? It's my defense. It may seem irrational or stupid to someone else, but it works for me.
I think that's the important thing about all of this. The defense works for Billy. It may not be real to any of us, as it is likely that none of us will ever time travel or visit the Tralfamadorians on their home planet, nor will they visit us, but they have visited Billy and he has visited them. I suppose in saying this I have just disqualified my first statement that Billy was not, in fact, travelling through time. So it goes. Billy is travelling through time because it is real to him. That is all that matters.