[maryz]

or some other kind of concrete evidence that can be accepted universally

????? Is there such a thing? BTW, if there's "concrete evidence" on anything, that thing is no longer a matter of faith, but of knowledge.

[1000 silverlings]

Well of course there’s such a thing. Historical documents, architectural ruins, Jewish genealogical records, all sorts of stuff. Or you can make up feel good stories and see if they float