Is there a way to test if something's from the future?
This is for a short story that I'm trying to perfect before sending out to various magazines.
The story concerns a man who, while digging his own pool, finds a skeleton. He calls the police who take the skeleton away, only to return it to him a month or two later after determining it's his own skeleton from the future.
I need an explanation--it doesn't have to be airtight, just believable--for how they might determine it's from the future. Carbon dating won't work, obviously, and right now I'm planning for them to make the pull by comparing his dental records and also the degeneration of the bones from arthritis (suggesting a more advanced case than his own), but I'm wondering if there's a marker that might suggest something is from the future.
CO2 levels in the bones/soil around the bones? Some kind of radiation that increases in concentration over time?