Some people only believe what they have seen with their own eyes. They say they believe in science, and dont believe in anything until things have been proven scientifically. Let's not forget that modern science has only been around a couple of hundred years and still has an awful lot to learn.
Even when hundreds of thousands of people all over the world report their experiences with orbs, spirits, angels, visions, past life experiences, near death experiences, miracle cures, these people will scoff at it because they like to live in their own little box and sneer at anything that might actually have to make them think beyond what's on tv and where they are going on their next holiday.
Even for me to say i have seen orbs myself they will discount that, say it was imaginary, i'm nuts whatever, go ahead i'm well used to it. I'm still not going to pretend that i don't see spirit just because you lot will make a laugh out of it.
Good on you, magnu for posting this thread, i find it a very interesting subject.