I doubt the 6 hour limit is actually the snapping point. It’s just the limit to what you can do before you start to deal damage to reality.
If the six hour limit is or resembles a natural limit of any kind, which it may, it seems most likely to correspond to one quarter of a day, where “day” might be sidereal, stellar, or solar (probably not civil). Hours are just… very artificial, and while magic seems perfectly happy to abide by artificial rules, this limit is likely to predate accurate timekeeping (and accurate timekeeping precedes the careful pinning down of how long an hour is!)
The “quarter-day” interpretation would have the following implications:
Depending on which sort of day limits time travel, certain astronomical phenomena would mess with time travel.
Six hours is unlikely to be an exact figure, and the figure in question may vary depending on seasonal and geographical context.
Time travel in outer space will behave very strangely.
Maybe the natural limit is some naturally derived constant that happens to be slightly more than six hours, and the time-turner was designed by humans to operate in units of exactly an hour. Which you could test by seeing if it was possible to send information back in time 6 hours and 1 second using two chained time-turners.
This makes for an interesting question: How do you test stuff like this?
It seems dangerous. What exactly breaks when you go back too far? Just the local area? Can I launch a time turner into space with a suitable automatic device and watch from a safe distance? Is having an observer involved relevant (more likely with magic than quantum mechanics)? Would testing with wizard or house elf participants be unethical? Is the anthropic principle relevant?
If the six hour limit is or resembles a natural limit of any kind, which it may, it seems most likely to correspond to one quarter of a day, where “day” might be sidereal, stellar, or solar (probably not civil). Hours are just… very artificial, and while magic seems perfectly happy to abide by artificial rules, this limit is likely to predate accurate timekeeping (and accurate timekeeping precedes the careful pinning down of how long an hour is!)
The “quarter-day” interpretation would have the following implications:
Depending on which sort of day limits time travel, certain astronomical phenomena would mess with time travel.
Six hours is unlikely to be an exact figure, and the figure in question may vary depending on seasonal and geographical context.
Time travel in outer space will behave very strangely.
Maybe the natural limit is some naturally derived constant that happens to be slightly more than six hours, and the time-turner was designed by humans to operate in units of exactly an hour. Which you could test by seeing if it was possible to send information back in time 6 hours and 1 second using two chained time-turners.
This makes for an interesting question: How do you test stuff like this?
It seems dangerous. What exactly breaks when you go back too far? Just the local area? Can I launch a time turner into space with a suitable automatic device and watch from a safe distance? Is having an observer involved relevant (more likely with magic than quantum mechanics)? Would testing with wizard or house elf participants be unethical? Is the anthropic principle relevant?