What does it mean to "believe" in something you can't observe or understand? There's a sort of frontier where you make observations, form and test theories, and grow to understand the observations. We agree that crank theories, without evidence and unable to prove anything, are indistinguishable from the supernatural. So what good does it do us to consider them? We should explore things within the frontier - does infrasound cause ghost sightings? if so, does that summon ghosts or change the brain? - on a materialist basis, like some of the fringe scientists are trying to do. Invisible teapots that humans will be able to see in 3000 years should be dismissed as idealism.