Blasters
are
a
well
known
and distinctive part of the Star Wars universe, and
without them, a lot more Storm Troopers would still be alive.
While they worked very well at killing in the movies, they would not
work very well in our world. This is because a blaster bolt is
made of plasma, and plasma tends to dissipate and loose energy very
well in the air.
This serves as an advantage to plasmas in the vacuum of
space, where it
would take a lot longer for the plasma to dissipate and it would not
loose heat nearly so quickly.
The
only
problems
with
plasmas being used in star ship to
star ship battles, is the fact that there are much cheaper and easier
ways of
making neat, useful machines into burning unpleasant piles of
slag. Just ask Michael Bay about Transformers.