One of the basic requirements on this site is that questions must be empirically verifiable.
If a claim is notable, and could in theory be subject to empirical verification, but the likelihood of such verification actually happening in our lifetimes is low, is a question about such claim on-topic for this site?
Famous politician X claims that there is a library buried 10,000 meters under the Great Pyramid of Giza.
The chances of someone getting sufficient funding, archaeological permits, equipment, personnel, etc. today to actually dig 10,000 meters under a world heritage site is virtually nil, but admittedly not actually zero. How should such a question be handled on this site?
- Close it as non-verifiable?
- Admit that it is notable and verifiable, but close it for another reason (e.g. impractical)?
- Leave it open in the hopes that someday our distant descendants 1,000 years in the future might be able to answer it?
Similar questions could include claims about lost artifacts (e.g. exact size of the Holy Grail), claims about the existence of specific features on faraway planets/moons that we cannot examine in sufficient detail yet to verify (e.g. "There is a 10.3 ton granite rock with a symbol of a triangle carved on it submerged 100m off the coast in one of the hydrocarbon seas of Titan."), claims that cannot be verified due to legal constraints (e.g. documents that would be required to verify the claim cannot legally be disclosed, performing necessary experiments would constitute a criminal offense, etc.), or similar claims with practical barriers to verification.