Thanks for the quick explanation. So that information was already there, and thus I wouldn’t call that sending information back in time.
The problem is that all information is “already there”, time itself is arguably how discovering implications of information that is already here feels from the inside. That is, when the world is viewed through deterministic laws, there is never any information that is present in the future, but “logically” absent from the past. The only difference between what is found in the past and what is found in the future is that it takes time to reach (=compute) more “distant” facts.
time itself is arguably how discovering implications of information that is already here feels from the inside
What do you mean by “here”—your brain? or a spacelike slice across the whole universe?
If a glass falls on the ground and shatters, is it “discovering implications of information”, etc? If the answer is yes, does that mean it feels like something for the glass to shatter?
Is someone really obligated to define “mind” just in order to demonstrate that a glass is not in the set of things that has one? I can’t define “game” but “the weak nuclear force” is not an example of one.
If I read him correctly, Vladimir is proposing to make time itself a mind-dependent phenomenon. Time happens inside minds but not inside shattering glasses. So he needs to explain the difference.
time itself is arguably how discovering implications of information that is already here feels from the inside
Time itself is how a certain process feels from the inside. If time is a feeling, it can only happen where there are feelings, so if it happens inside shattering glasses, then they have feelings.
“I do see a gray area that in a deterministic universe, any message that we would want to send from the future could be predicted now, so we in the future don’t really need to send the message back—we in the present just need to predict what the message is.”
What you’ve written has clarified this even further—depending upon the ‘opacity’ of the message, we might not be able to decipher the message any faster than just waiting for the future to evolve it.
I have a strange motive for these questions. I now understand that this message I’m worried about is ‘already here’ in some sense, and that is relevant. It might actually make my parent question moot. However, I think that that depends—unexpectedly, for me—on whether all information from the past is accessible to the future.
Information is not gained as you move forward in time. However, do you lose any information as you move forward in time?
In time-reversible deterministic world, information is gained from observation of stuff that wasn’t in contact with you in the past, and logical information is also gained (new knowledge about facts following from the premises—there is no logical transparency). Analogously, an action can be seen as “splitting”, where you part with a prepared action, and action parts with you, so that you lose knowledge of that action. If you let info split away in this manner, you may never get it back.
I’ll contribute my thoughts on whether the world is time-reversible...
By time-reversible, I mean that information doesn’t get “lost” as you move forward in time; that with unlimited information about the universe at time t you could deduce everything about the state of the universe at time t-ε.
Classical mechanics is reversible. If you have the velocity and positions of 3 billiard balls, you can deduce if and when they collided and what their original velocities were.
I think what we know about quantum mechanics is inconclusive; we don’t know how to trace the wave-function backwards in a unique/deterministic way, but we don’t know how to follow it forwards, either.
If you many-worlds, then all possible past universes make up the past universe, so you seem to have reversibility—a reversibility that is no less determined and unique in the past direction as the future direction.
Being agnostic about many worlds, I would give a higher probability for reversibility over non-reversibility, just because of the reversibility of classical mechanics. However, 51% in favor of reversibility for a hand-waving intuition is pretty much just a random guess and I wonder if anyone has a tighter probability estimate, or other reasons?
In Many Worlds Quantum Mechanics, the wave function is fundamental, and the many worlds are a derived consequence. The wave function is time reversable. Running it backwards, you would see worlds merge together, not the world we currently experience splitting into possible precursors. This assymetry is due to simple boundry conditions at the beginning of time.
OK, with the world not splitting into possible precursors as you go backwards in time, this means the universe is time reversible. That’s what you said I guess when you wrote that the wave function is time reversible.
Hmm. So even quantum mechanics supports reversibility. Thanks.
Thanks for the quick explanation. So that information was already there, and thus I wouldn’t call that sending information back in time.
The problem is that all information is “already there”, time itself is arguably how discovering implications of information that is already here feels from the inside. That is, when the world is viewed through deterministic laws, there is never any information that is present in the future, but “logically” absent from the past. The only difference between what is found in the past and what is found in the future is that it takes time to reach (=compute) more “distant” facts.
What do you mean by “here”—your brain? or a spacelike slice across the whole universe?
If a glass falls on the ground and shatters, is it “discovering implications of information”, etc? If the answer is yes, does that mean it feels like something for the glass to shatter?
Sure.
No.
Why not?
Because a glass has no mind, naturally.
Can you justify that in a noncircular way? What’s a mind, and why doesn’t a glass have one?
Is someone really obligated to define “mind” just in order to demonstrate that a glass is not in the set of things that has one? I can’t define “game” but “the weak nuclear force” is not an example of one.
If I read him correctly, Vladimir is proposing to make time itself a mind-dependent phenomenon. Time happens inside minds but not inside shattering glasses. So he needs to explain the difference.
Time does happen inside shattering glasses, and it’s not “mind-dependent”. Happy?
But you said:
Time itself is how a certain process feels from the inside. If time is a feeling, it can only happen where there are feelings, so if it happens inside shattering glasses, then they have feelings.
That was a reference to “how an algorithm feels from the inside”, with “feels” not intended for literal interpretation.
That was a reference to “how an algorithm feels from the inside”, with “feels” not intended for literal interpretation.
Yes. I was about to write,
“I do see a gray area that in a deterministic universe, any message that we would want to send from the future could be predicted now, so we in the future don’t really need to send the message back—we in the present just need to predict what the message is.”
What you’ve written has clarified this even further—depending upon the ‘opacity’ of the message, we might not be able to decipher the message any faster than just waiting for the future to evolve it.
I have a strange motive for these questions. I now understand that this message I’m worried about is ‘already here’ in some sense, and that is relevant. It might actually make my parent question moot. However, I think that that depends—unexpectedly, for me—on whether all information from the past is accessible to the future.
Information is not gained as you move forward in time. However, do you lose any information as you move forward in time?
In time-reversible deterministic world, information is gained from observation of stuff that wasn’t in contact with you in the past, and logical information is also gained (new knowledge about facts following from the premises—there is no logical transparency). Analogously, an action can be seen as “splitting”, where you part with a prepared action, and action parts with you, so that you lose knowledge of that action. If you let info split away in this manner, you may never get it back.
You’re a little over my head—though I mostly follow.
My question was actually simpler. Is the world time-reversible? Do we know anything about that?
I’ll contribute my thoughts on whether the world is time-reversible...
By time-reversible, I mean that information doesn’t get “lost” as you move forward in time; that with unlimited information about the universe at time t you could deduce everything about the state of the universe at time t-ε.
Classical mechanics is reversible. If you have the velocity and positions of 3 billiard balls, you can deduce if and when they collided and what their original velocities were.
I think what we know about quantum mechanics is inconclusive; we don’t know how to trace the wave-function backwards in a unique/deterministic way, but we don’t know how to follow it forwards, either.
If you many-worlds, then all possible past universes make up the past universe, so you seem to have reversibility—a reversibility that is no less determined and unique in the past direction as the future direction.
Being agnostic about many worlds, I would give a higher probability for reversibility over non-reversibility, just because of the reversibility of classical mechanics. However, 51% in favor of reversibility for a hand-waving intuition is pretty much just a random guess and I wonder if anyone has a tighter probability estimate, or other reasons?
In Many Worlds Quantum Mechanics, the wave function is fundamental, and the many worlds are a derived consequence. The wave function is time reversable. Running it backwards, you would see worlds merge together, not the world we currently experience splitting into possible precursors. This assymetry is due to simple boundry conditions at the beginning of time.
OK, with the world not splitting into possible precursors as you go backwards in time, this means the universe is time reversible. That’s what you said I guess when you wrote that the wave function is time reversible.
Hmm. So even quantum mechanics supports reversibility. Thanks.