Are we alone?

Are we alone in the universe?  If you believe that the bible is true....then the answer is no.  There are angels & demons (fallen angels) as well as other beings such as seraphim, cherubim, etc.  I think when many ask this question they mean to ask if there are any other beings who are limited to the physical, three dimensional universe that we humans are currently in.  I find it hard to believe that a Creator who filled this earth with so much wonder and variety would only place life on one planet.  As far as intelligent life elsewhere, that may be more difficult to answer.  I believe there are higher realms/dimensions that are filled with intelligent beings.  This may be what many people call "Heaven".  If this life is a test (good or evil) then who is to say that after death you do not face more tests in other realms? Could it be that what some people think of as reincarnation is actually memories of another realm/planet.....or even a parallel earth?  If our souls are eternal....how can they have a beginning?