any more than that and information is traveling more than 6 hours back. (at least from the perspectives of the earliest and latest self-clone)
I believe the only restriction is on not traveling back more than six hours by wall-clock time. It’s never stated that you can’t travel back into the same hour more than six time using more than one Time-Turner.
The universe makes it rather obvious that you can’t. How do we know that? Because the economics of Time-Turners is such that they are only valuable if you have exactly one and any additional time-turners are irrelevant. If time-turners worked that way then...
… You would want as many as you could get. And Hogwarts wouldn’t be able to loan them out. If each person can only use 1 time-turner (as I say), then the economic demand is at most the population who’s aware of time-turners. If you can use infinitely many time turners, then demand is without limit. The price for them would increase, and Hogwarts wouldn’t be free to hand them out like they relatively were inexpensive.
They would have a very high price, and powerful or rich wizards would use them as much as they want. People as rich as Lucius Malfoy would be wearing twenty five time-turners like they were the rapper flava-flav. Upon hearing about Azkaban being attacked, you’d immediately go back six hours instead of one because there would be no reason to not do it. Harry, upon exiting the Azkaban wards, would have run into a patrol of a thousand disillusioned Dumbledores patrolling the sky. Hermione would have gotten arrested, and McGonagall would temporarily recall all the time-turners so that Harry or Dumbledore could have a week of turned time to come up with a defense.
No, the universe does not appear as it would if time turners could be stacked. Indeed if they could, things would look drastically different.
I don’t think there’s a strong economic argument against multiple Time-Turners—I can think of a number of reasons why the demand for additional loops might run into diminishing returns pretty quickly. Starting with self-consistency problems—if the simplest solution to a factoring problem that leverages Time-Turning is “DO NOT MESS WITH TIME”, then it wouldn’t surprise me too much if the simplest self-consistent solution to more complicated and dangerous tasks that involve self-reference is a mysterious death or incapacity on the first iteration. This would be noticed, and Time-Turner abuse would be avoided. Then there’s jet lag, synchronization issues, and any number of other things. More than one Time-Turner would definitely be useful (and desired), but the twenty-fifth wouldn’t be anywhere close to as useful as the first.
That being said, I think you present pretty solid behavioral reasons why we can probably assume it’s impossible.
Very true. Only defense is that people are generally dumb and unimaginative. But that’s a pretty good defense in a fictional universe, even if it is a fully general response to some things.
Dumbledore doesn’t give a straight answer when Harry asks if more than one time turner can be used to get more than 30 hours.
There was another slight pause, during which Harry went on smiling. He was a little apprehensive, actually a lot apprehensive, but once it had become clear that Dumbledore was deliberately messing with him, something within him absolutely refused to sit and take it like a defenseless lump.
“I’m afraid Time doesn’t like being stretched out too much,” said Dumbledore after the slight pause, “and yet we ourselves seem to be a little too large for it, and so it’s a constant struggle to fit our lives into Time.”
On the other hand, we may infer that thirty hours is the limit from e.g. Amelia Bones’ behavior in the Azkaban arc:
“I’ll check if we have anything from six hours forward,” said the voice of Madam Bones, “if so they wouldn’t have told me, but I’ll have them tell you. Do you have anything you want to tell me, Albus? Which of those two possibilities is it looking like?”
That’s just the usual limit on information not traveling more than six wall-clock hours back in time, total. It doesn’t say or imply that you can’t loop yourself more than six times within a small stretch of wall-time.
Actually, if you can loop yourself more than six times at any small stretch of wall-time then you can get more than 30 subjective hours in one 24 wall-time day.
But it’s implied you can’t actually do that, which is why I think no more than 6 copies at any given time.
Plus, if it were possible you could basically use any one day as a stopping point groundhog-day style in which you can (for example) brute-force read the entire Hogwarts library.
At any rate, the general limiting principle is that information cannot travel more than 6 hours backwards, Which I think means that when you draw a graph of a person using time-turners where you represent her using an arrow (going right for positive time, and left in 1h jumps for time-turner use), Then you can’t have more than 6 hours of left-arrow in any given 24h wall-time section.
Plus, if it were possible you could basically use any one day as a stopping point groundhog-day style in which you can (for example) brute-force read the entire Hogwarts library.
There was another pause, and then Madam Bones’s voice said, “I have information which I learned four hours into the future, Albus. Do you still want it?”
Albus paused -
(weighing, Minerva knew, the possibility that he might want to go back more than two hours from this instant; for you couldn’t send information further back in time than six hours, not through any chain of Time-Turners)
I believe the only restriction is on not traveling back more than six hours by wall-clock time. It’s never stated that you can’t travel back into the same hour more than six time using more than one Time-Turner.
The universe makes it rather obvious that you can’t. How do we know that? Because the economics of Time-Turners is such that they are only valuable if you have exactly one and any additional time-turners are irrelevant. If time-turners worked that way then...
… You would want as many as you could get. And Hogwarts wouldn’t be able to loan them out. If each person can only use 1 time-turner (as I say), then the economic demand is at most the population who’s aware of time-turners. If you can use infinitely many time turners, then demand is without limit. The price for them would increase, and Hogwarts wouldn’t be free to hand them out like they relatively were inexpensive.
They would have a very high price, and powerful or rich wizards would use them as much as they want. People as rich as Lucius Malfoy would be wearing twenty five time-turners like they were the rapper flava-flav. Upon hearing about Azkaban being attacked, you’d immediately go back six hours instead of one because there would be no reason to not do it. Harry, upon exiting the Azkaban wards, would have run into a patrol of a thousand disillusioned Dumbledores patrolling the sky. Hermione would have gotten arrested, and McGonagall would temporarily recall all the time-turners so that Harry or Dumbledore could have a week of turned time to come up with a defense.
No, the universe does not appear as it would if time turners could be stacked. Indeed if they could, things would look drastically different.
I don’t think there’s a strong economic argument against multiple Time-Turners—I can think of a number of reasons why the demand for additional loops might run into diminishing returns pretty quickly. Starting with self-consistency problems—if the simplest solution to a factoring problem that leverages Time-Turning is “DO NOT MESS WITH TIME”, then it wouldn’t surprise me too much if the simplest self-consistent solution to more complicated and dangerous tasks that involve self-reference is a mysterious death or incapacity on the first iteration. This would be noticed, and Time-Turner abuse would be avoided. Then there’s jet lag, synchronization issues, and any number of other things. More than one Time-Turner would definitely be useful (and desired), but the twenty-fifth wouldn’t be anywhere close to as useful as the first.
That being said, I think you present pretty solid behavioral reasons why we can probably assume it’s impossible.
For some reason I found this image irresistibly hilarious. The sky is filled with two thousand twinkling stars!
Very true. Only defense is that people are generally dumb and unimaginative. But that’s a pretty good defense in a fictional universe, even if it is a fully general response to some things.
Didn’t Harry ask Dumbledore if it’s possible to get more than 30 hours in a day using multiple time-turners and getting a negative answer?
I’m not sure he got a plainly stated negative answer. Can someone look that up?
Dumbledore doesn’t give a straight answer when Harry asks if more than one time turner can be used to get more than 30 hours.
On the other hand, we may infer that thirty hours is the limit from e.g. Amelia Bones’ behavior in the Azkaban arc:
That’s just the usual limit on information not traveling more than six wall-clock hours back in time, total. It doesn’t say or imply that you can’t loop yourself more than six times within a small stretch of wall-time.
Actually, if you can loop yourself more than six times at any small stretch of wall-time then you can get more than 30 subjective hours in one 24 wall-time day.
But it’s implied you can’t actually do that, which is why I think no more than 6 copies at any given time. Plus, if it were possible you could basically use any one day as a stopping point groundhog-day style in which you can (for example) brute-force read the entire Hogwarts library.
At any rate, the general limiting principle is that information cannot travel more than 6 hours backwards, Which I think means that when you draw a graph of a person using time-turners where you represent her using an arrow (going right for positive time, and left in 1h jumps for time-turner use), Then you can’t have more than 6 hours of left-arrow in any given 24h wall-time section.
That would get rather crowded.
McGonagall thinks so, at least: