For the sake of argument, let’s assume that in later chapters we will discover that Harry’s future goes according to the plan he lays out… that is, at T1 Minerva sends her Patronus, and at T2 Harry gets out of Azkaban and travels to T1.
So at T1 Harry is in Azkaban and in Mary’s Room.
If the Patronus finds Harry in Azkaban (as we’ve read), Harry travels to T1 in order to be found by Minerva, as you say.
But if the Patronus finds Harry in Mary’s Room (as you’re arguing couldn’t happen), then Harry travels to T1 for some other reason, or no reason at all.
“But then there’s no actual motivation for Harry’s action!”, I hear someone object. “No fair!”
Well, I agree. Similarly, by this theory, there’s no actual motivation for the Patronus’ choice.
“Because it would cause a paradox” is a little bit like “Because it would violate conservation of energy”… it’s a reason to predict one consequence over another, but it isn’t actually an explanation.
Think of the interference patterns of the double slit experiment. The wave-functions of universes with paradoxes cancel out to give zero probability to those collective sets of conditions.
Er… really?
For the sake of argument, let’s assume that in later chapters we will discover that Harry’s future goes according to the plan he lays out… that is, at T1 Minerva sends her Patronus, and at T2 Harry gets out of Azkaban and travels to T1.
So at T1 Harry is in Azkaban and in Mary’s Room.
If the Patronus finds Harry in Azkaban (as we’ve read), Harry travels to T1 in order to be found by Minerva, as you say.
But if the Patronus finds Harry in Mary’s Room (as you’re arguing couldn’t happen), then Harry travels to T1 for some other reason, or no reason at all.
“But then there’s no actual motivation for Harry’s action!”, I hear someone object. “No fair!”
Well, I agree. Similarly, by this theory, there’s no actual motivation for the Patronus’ choice.
“Because it would cause a paradox” is a little bit like “Because it would violate conservation of energy”… it’s a reason to predict one consequence over another, but it isn’t actually an explanation.
Of course, I will admit that I am confused about what local laws could add up to the “no paradox” global law.
Something like a multiply-branching Universe in which those branches that turn out to contain paradoxes cease to exist?
Not “cease to exist”, simply won’t exist.
Think of the interference patterns of the double slit experiment. The wave-functions of universes with paradoxes cancel out to give zero probability to those collective sets of conditions.