The loop works because the conductor Harry that uses the Time-Turner at 6 PM is a younger version of the conductor Harry at 5 PM. Conductor Harry at 5:30 PM is going to go sit in the trunk at 6 PM, so he has no further need of the Time-Turner.
I think the most elegant formulation of a restriction that would prevent this (as well as all the things explicitly prevented in HPMoR) is that no path along which information or matter travels can stretch more than 30 hours per 24 hours.
I’d say yes (until the 24 hours run out and the pebble stops being time-stretched).
Similarly, if you go back 6 hours in time and, say, cast a spell that creates fireworks visible from a large distance, you’ve just prevented everyone within that radius from using a Time-Turner.
Finally, I’m mostly sure that the incredibly-small-scale changes caused by simply going back in time 6 hours propagate quickly enough that only one person on Earth can use a Time-Turner on any given day.
So yeah, there’s a bit of a problem here. Presumably this is one of those “it works how Merlin would have expected it to work” things.
The loop works because the conductor Harry that uses the Time-Turner at 6 PM is a younger version of the conductor Harry at 5 PM. Conductor Harry at 5:30 PM is going to go sit in the trunk at 6 PM, so he has no further need of the Time-Turner.
I think the most elegant formulation of a restriction that would prevent this (as well as all the things explicitly prevented in HPMoR) is that no path along which information or matter travels can stretch more than 30 hours per 24 hours.
So, you could put a 6-hour stretched pebble in someone’s pocket, and they wouldn’t be able to use a Time-Turner?
I’d say yes (until the 24 hours run out and the pebble stops being time-stretched).
Similarly, if you go back 6 hours in time and, say, cast a spell that creates fireworks visible from a large distance, you’ve just prevented everyone within that radius from using a Time-Turner.
Finally, I’m mostly sure that the incredibly-small-scale changes caused by simply going back in time 6 hours propagate quickly enough that only one person on Earth can use a Time-Turner on any given day.
So yeah, there’s a bit of a problem here. Presumably this is one of those “it works how Merlin would have expected it to work” things.
hey