What makes you think people who astral travel have not been able to prove it to scientists? I think what you're really asking is that if astral travel was real, it would be easy to test scientifically and therefore the whole world would know about it and be easily able to believe in it since it's been scientifically proven. Right?
Let's pretend it's the year 1149 and someone is going on about atoms and quarks and stuff like that. And let's pretend there is a message board. Humor me. And someone comes on and asks, "how come people who claim that atoms exist are not able to prove it to scientists?" The answer: Because no one has invented a device or tool capable of detecting them. Doesn't mean they aren't there.
We're all waiting for "science" to catch up with those of us experiencing this phenomenon.
