KMS

It's not. Apparitions can be a number of things, not just the classical wandering spirit.

As for science - 500 years back science was convinced that the earth was flat and the center of the Universe. What do you think science will evolve to if humans are around another 500?

Can't keep a closed mind to what you see and experience. But you as well can't be set in a belief 'entirely'. The only things that are irrational spiritually speaking are the planets major religions, but that's because they're philosophically moronic and any intelligent human can pick them apart.