One of the themes of current scientific progress is getting more and more information out of tiny amounts of data.
I think that if the universe was once a single spot and everything we see comes from there, then the information about everything is everywhere. If we had knowledge of the mechanics and enough computing power we could understand what has happened in the universe since the start just by observing the current state of one atom.
This is because, if we could measure them with full precision, the current position, direction, and speed of an atom (and all other measurements if we could do them physically) are only possible with one and only one specific history of everything else in the universe.
...to what extent can people be re-created from what they’ve left behind them...
I think us or any other intelligent species that continues after us will control every aspect of our environments. Just like now we are starting to understand the full “language” of DNA and we are in the first steps of cloning, AI, etc., we will also control the planetary weather, solar system level direction and orbits of planets, etc.
In this context it will be very easy to replicate past living beings. The problem is that because they will be operating on a different set of materials (h2o, salts, carbon, etc.) it will not actually be that original person even if it’s an exact replica.
Unless there is some sort of entanglement possible, I think that If a person is copied, the copy is not the original person unfortunately, so when we die we will not be back unless its on the same set of materials, which is possible, but very improbable.
EDIT: The above phrase:
This is because, if we could measure them with full precision, the current position, direction, and speed of an atom (and all other measurements if we could do them physically) are only possible with one and only one specific history of everything else in the universe.
Replaced the original sentence:
This is because the current position, direction, and speed of an atom (and all other measurements that can be done physically) are only possible with one and only one specific history of everything else in the universe.
To reflect, as observed in the comments below by lesswrong.com/user/asr/, that “You can measure those things to only finite precision”.
This is because the current position, direction, and speed of an atom (and all other measurements that can be done physically) are only possible with one and only one specific history of everything else in the universe.
This seems almost certainly false. You can measure those things to only finite precision—there is a limit to the number of bits you can get out of such a measurement. Suppose you measure position and velocity to one part in a billion in each of three dimensions. That’s only around 200 bits—hardly enough to distinguish all possible universal histories.
This is because, if we could measure them with full precision, the current position, direction, and speed of an atom (and all other measurements if we could do them physically) are only possible with one and only one specific history of everything else in the universe.
I will edit above.
Other than our ability to measure these dimensions I think that their current state is only possible with only one history of the universe since the beginning.
That is not at all true; for example, see the inverse problem (http://en.wikipedia.org/wiki/Inverse_problem). Although the atom’s position is uniquely determined by the rest of the universe, the inverse is not true: Multiple different states of the universe could correspond to the same position of the atom. And as long as the atom’s position does not uniquely identify the rest of the outside universe, there is no way to infer the state of the universe from the state of the atom, no matter how much precision you can measure it with. The reason is that there are many ways that the boundary conditions of a box containing an atom could be arranged, in order to force it to any position, meaning that there is a limited amount that the atom can tell you about its box.
The atom is affected by its local conditions (electromagnetic and gravitational fields, etc), but there are innumerable ways of establishing any particular desired fields locally to the atom.
This causes challenges when, for example, you want to infer the electrical brain activity in a patient based on measurements of electromagnetic fields at the surface. Unfortunately, there are multiple ways that electrical currents could have been arranged in three-dimensional space inside the brain to create the same observed measurements at the surface, so it’s not always possible to “invert” the measurements directly without some other knowledge. This isn’t a problem of measurement precision; a finer grid of electrodes won’t solve it (although it may help rule out some possibilities).
Since I am not a scientist I didn’t know about the inverse problem, but I had thought about that intuitively.
I think it’s true that a current state of an atom, in a 3 dimensional context, may be achieved through multiple histories or even manipulated by a living being who wants to “cheat the system”.
But in a 4 dimensional context, where the coordinates on a base field (maybe Higgs field), which could also be called time, are included, that would eliminate the possibility of recreating the same position for different stories since time happens only once, in a forward motion, and thus making that state unique and irreplaceable.
I think a position of height x, width y, and depth z is replicable the way you say above.
But, is a position of height x, width y, depth z, at time w (considering a single time line since the big bang) replicable?
If yes then the inverse problem refutes my original idea in this thread, if not IMO it is still possible to reverse-understand the universe that way.
I think that if the universe was once a single spot and everything we see comes from there, then the information about everything is everywhere. If we had knowledge of the mechanics and enough computing power we could understand what has happened in the universe since the start just by observing the current state of one atom.
This is because, if we could measure them with full precision, the current position, direction, and speed of an atom (and all other measurements if we could do them physically) are only possible with one and only one specific history of everything else in the universe.
I think us or any other intelligent species that continues after us will control every aspect of our environments. Just like now we are starting to understand the full “language” of DNA and we are in the first steps of cloning, AI, etc., we will also control the planetary weather, solar system level direction and orbits of planets, etc.
In this context it will be very easy to replicate past living beings. The problem is that because they will be operating on a different set of materials (h2o, salts, carbon, etc.) it will not actually be that original person even if it’s an exact replica.
Unless there is some sort of entanglement possible, I think that If a person is copied, the copy is not the original person unfortunately, so when we die we will not be back unless its on the same set of materials, which is possible, but very improbable.
EDIT: The above phrase:
Replaced the original sentence:
To reflect, as observed in the comments below by lesswrong.com/user/asr/, that “You can measure those things to only finite precision”.
This seems almost certainly false. You can measure those things to only finite precision—there is a limit to the number of bits you can get out of such a measurement. Suppose you measure position and velocity to one part in a billion in each of three dimensions. That’s only around 200 bits—hardly enough to distinguish all possible universal histories.
I agree, I should have written a conditional:
I will edit above.
Other than our ability to measure these dimensions I think that their current state is only possible with only one history of the universe since the beginning.
That is not at all true; for example, see the inverse problem (http://en.wikipedia.org/wiki/Inverse_problem). Although the atom’s position is uniquely determined by the rest of the universe, the inverse is not true: Multiple different states of the universe could correspond to the same position of the atom. And as long as the atom’s position does not uniquely identify the rest of the outside universe, there is no way to infer the state of the universe from the state of the atom, no matter how much precision you can measure it with. The reason is that there are many ways that the boundary conditions of a box containing an atom could be arranged, in order to force it to any position, meaning that there is a limited amount that the atom can tell you about its box.
The atom is affected by its local conditions (electromagnetic and gravitational fields, etc), but there are innumerable ways of establishing any particular desired fields locally to the atom.
This causes challenges when, for example, you want to infer the electrical brain activity in a patient based on measurements of electromagnetic fields at the surface. Unfortunately, there are multiple ways that electrical currents could have been arranged in three-dimensional space inside the brain to create the same observed measurements at the surface, so it’s not always possible to “invert” the measurements directly without some other knowledge. This isn’t a problem of measurement precision; a finer grid of electrodes won’t solve it (although it may help rule out some possibilities).
Thx so much for the link above!
Since I am not a scientist I didn’t know about the inverse problem, but I had thought about that intuitively.
I think it’s true that a current state of an atom, in a 3 dimensional context, may be achieved through multiple histories or even manipulated by a living being who wants to “cheat the system”.
But in a 4 dimensional context, where the coordinates on a base field (maybe Higgs field), which could also be called time, are included, that would eliminate the possibility of recreating the same position for different stories since time happens only once, in a forward motion, and thus making that state unique and irreplaceable.
I think a position of height x, width y, and depth z is replicable the way you say above.
But, is a position of height x, width y, depth z, at time w (considering a single time line since the big bang) replicable?
If yes then the inverse problem refutes my original idea in this thread, if not IMO it is still possible to reverse-understand the universe that way.
Ah, hmm.… Maybe! If you include the entire history of the atom, then I’m not actually sure. That’s a tough question, and a good question =)
If you can only measure them to some finite precision, they may not have more precision than that.