There was a time when most ideas of immortality were of the
religious variety that were usually stated as something like
"immortality is attained by dying and going to heaven".
No one ever seemed to describe exactly how that would happen or what
it would look like. It is usually imagined as another body that
looks exactly like the one that we have now, but that is somehow
magically different. (I say magically because what could make the
corruptible incorruptible?) Hence, in movies people who die
sometimes reappear as ghosts looking exactly the same and even
 wearing the exact same clothes. So the basic idea behind this is that
immortality is achieved by "going somewhere else", there is
something wrong with "here", and there is somewhere else that is a
better place. Just where this place could be `placed' is not
understood.  So where might heaven be located? Is it
in the far reaches of the universe? Would it be in a parallel
universe or alternate reality?

  In the most recent times, many have stopped believing in such
things as heaven. The so called `scientific' mind states that
we can only know what we perceive with our senses. Our bodies are seen
as having evolved from the same stuff that creates mud or stars. We
are biological machines that have attained self consciousness
(whatever that is!). What becomes of immortality within this
belief system? It becomes a simple case of exchanging body parts to
stay alive forever. The ideas go from as subtle as coaxing the
body to grow new cells to replace damaged ones,  to as gross as
exchanging body parts with mechanical duplicates. Just rebuild the
engine and keep it oiled, and maybe we won't have to address the
question of exactly what is `self consciousness'.

  Both of the above ideas have one thing in common. They both
ignore the fact that

   "physical matter" has been incontrovertibly proven to
    not exist.