rationalskepticism.org

Something does not need to be observed to exist : as by that logic nothing existed before human perception
We know however that that is blatantly false : furthermore there is no required validation of existence
beyond whatever it is that is existing actually existing : as to how one can then know something
exists without perceiving it the simple answer to that is that one does not : whatever it is
will still exist whether one is aware of it or not : it is the very nature of existence that
is the sole determining factor here not whether or not one can perceive of such an
existence : that question although important is not the most important one
pertaining to existence : to illustrate this let me turn it upside down :
you know that you exist but someone or something that does not
know this cannot comprehend your existence : so logically you
both exist and do not exist : this is obviously nonsensical
so therefore validation is not what is necessary here
but existence itself : we need it however as a
reference point for our day to day existence
but in purely philosophical terms though
it is not necessary at all : not at all