It's Official: We Were WRONG About the Big Bang

Say one day we discovered another universe expanding into our own. With its own potentially infinite number of galaxies. And its own potentially infinite number of lives. And we knew over the span of infinity it would eventually crush our own universe. With no way for us to ever interact with it, safe for one thing: triggering a vacuum collapse and be rid of it. For the sake of our own infinity, should we destroy another?