Such a scheme would presumably wind up with the message “DO NOT MESS WITH TIME” being sent back.
(A sort of theory of relativity, but for fixed time travel instead of a fixed maximum velocity, would be a more interesting solution. I don’t think this is possible to create, however.)
This happens whether or not you do it on purpose. Every time anyone goes back in time, they bring information that they weren’t stopped. Ergo, if someone brings back a paper that says “DO NOT MESS WITH TIME”, you know something was up. It would facilitate the information transfer. And thanks to conservation of expected evidence, every time someone doesn’t bring back a paper like that, you are now more certain that something like that didn’t happen.
Sorry, I wasn’t clear enough. My claim was that p(message[*]|attempt to send info back more than six hours)=1. This is at least reasonable- it’s almost exactly analogous to what happened to Harry in his experimenting.
[*]: More precisely, that the only result is that a message, with no identifying marks, appears in a location nobody is watching, and so forth. Wizards might still try to draw conclusions from this, but they would be wrong.
[**]: Since this is a fictional universe, we can directly specify its fundamental laws with 100% confidence. If this isn’t a fundamental law, then whenever this can be violated so can the 6-hour rule. (eg if this is something Merlin put in place to prevent dangerous experimenting, or whatever.)
If someone plans to go back in time, and doesn’t plan to be interrupted, they won’t normally get the message because they weren’t trying to find a loophole. If someone else decides to send a message further back by standing in front of where they were and going back in time, then how will that message change anything? I suppose it could send you the message before you even think about that, but what if it’s spur of the moment? Will it send you a message just because you were going to do something? Then again, it’s not as if those messages can’t be used to get information. Dumbledore totally did that when he found that message saying “no”.
Such a scheme would presumably wind up with the message “DO NOT MESS WITH TIME” being sent back.
(A sort of theory of relativity, but for fixed time travel instead of a fixed maximum velocity, would be a more interesting solution. I don’t think this is possible to create, however.)
This happens whether or not you do it on purpose. Every time anyone goes back in time, they bring information that they weren’t stopped. Ergo, if someone brings back a paper that says “DO NOT MESS WITH TIME”, you know something was up. It would facilitate the information transfer. And thanks to conservation of expected evidence, every time someone doesn’t bring back a paper like that, you are now more certain that something like that didn’t happen.
Sorry, I wasn’t clear enough. My claim was that p(message[*]|attempt to send info back more than six hours)=1. This is at least reasonable- it’s almost exactly analogous to what happened to Harry in his experimenting.
[*]: More precisely, that the only result is that a message, with no identifying marks, appears in a location nobody is watching, and so forth. Wizards might still try to draw conclusions from this, but they would be wrong.
[**]: Since this is a fictional universe, we can directly specify its fundamental laws with 100% confidence. If this isn’t a fundamental law, then whenever this can be violated so can the 6-hour rule. (eg if this is something Merlin put in place to prevent dangerous experimenting, or whatever.)
If someone plans to go back in time, and doesn’t plan to be interrupted, they won’t normally get the message because they weren’t trying to find a loophole. If someone else decides to send a message further back by standing in front of where they were and going back in time, then how will that message change anything? I suppose it could send you the message before you even think about that, but what if it’s spur of the moment? Will it send you a message just because you were going to do something? Then again, it’s not as if those messages can’t be used to get information. Dumbledore totally did that when he found that message saying “no”.