What do you mean “outside this universe”? Isn’t everything inside this universe by definition?
Suppose we run a cellular automaton simulation that initiates with some initial conditions and subsequently updates with a set of simple rules (e.g., like Newtonian mechanics or quantum mechanics or whatever) that sufficiently intelligent beings within the simulation could deduce and call ‘science’. Perhaps they could figure out they were in a simulation, and then everything in the simulation is their universe (there needn’t be any limits to the size of this universe) and everything outside it (of which they may know nothing) is outside it.
If you mean outside the part of the universe that we can interact with, how would it be any different.
There are a few ways entities within the simulation could deduce a reality outside their own. First, any acausal inconsistencies in their physical laws, suggesting someone tampering with the simulation. Similarly, any truly random elements would mean outside influence—though it would be a challenging project to be certain that any elements were truly random (and acausal). Another way they could deduce they were in a simulation is the lack of an explanation for the beginning of the simulation—though again, it would be challenging to be certain that there is NO explanation rather than just an unknown one.
If the beings want to call our universe part of their universe due to these interactions of having initiated them, seeding random numbers and occasionally interfering, that is fine, but then they need to differentiate between their simulation in which their science applies and the encapsulating universe for which they don’t know what sort of rules apply.
By the way, is there a way to see replies to your posts? I thought there wasn’t, but it seems unlikely that you’ve been checking this post every day for the past two years.
Funny! When you get mail, such as this one, the envelope under your user name turns red until you check it. Yours is probably currently red.
There are a few ways entities within the simulation could deduce a reality outside their own.
I don’t mean how would it be different from not having an outside universe. I mean: how would our universe containing the reason that there is a universe be different than only their universe existing and containing the reason that there is a universe?
In other words, if you live in universe A, and either your universe exists for some reason you don’t understand, or it exists within universe B, which exists for some reason you don’t understand, why would the latter hypothesis be less confusing?
how would our universe containing the reason that there is a universe be different than only their universe existing and containing the reason that there is a universe?
I think this is a good question, and I wanted to think a while before replying. (My train of thought motivated some other comments in reply to this post.)
Our universe does look different than a universe containing an explanation for existence. The universe we imagined several centuries ago, with spontaneous generation occurring everywhere and metaphysical intervention at many different levels, had more room for such an explanation.
For now (at least until you dig down into quantum mechanics, which I know nothing about), the universe appears to be a mechanical clock, with every event causally connected to a preceding event. Nothing, nothing is expected to happen without cause—this appears to be a very fundamental rule of our current paradigm of reality.
Simultaneously, I observe that I cannot even imagine how it could be possible for something to exist without cause. On the one hand, this might just reflect a limit in my intuition, and existence without cause might be possible. On the other hand, I will present an argument that an inability to imagine something, and indeed finding it illogical, is evidence that it is not possible. (Well, it’s a necessary but not sufficient condition.)
My argument is that any actual limits in this universe will be inherited by simulations within this universe, including the mental ones we use to draw intuition and logic. Like a shape in flatland finding it impossible to imagine escaping from a ring, we cannot imagine spontaneous creation if it is not possible. (This is the argument that an impossible thing cannot be simulated or imagined. Whether our inability to imagine something implies it is impossible depends upon how flexible our minds are; I think our minds are very flexible but QM may be the first piece of evidence that we can’t grasp some things that are possible.)
But if we lived in the universe imagined centuries ago, where entirely natural things like flies and light spontaneously appeared from their sources, then we would have a chance to study spontaneity and see how it works. If spontaneity was possible, we could imagine it and simulate it and learn about it. But if spontaneity cannot occur here, we can’t collect any information about it and it stands to reason it would be mysterious. This is exactly what our universe looks like.
Imagine we had a universe where something could come from nothing. Imagine we worked out how to find what happens at t+1, given t. This still wouldn’t be enough to know everything. We’d have to know what’s going on at some t less than ours (or greater, if we can just figure out t given t+1).
In other words, even a universe with spontaneity still has to have boundary conditions. Nothing exists at t=0 is the most obvious boundary condition, and it’s probably the most likely one, but it’s not the only possible one. There’s no reason it has to be that one.
Incidentally, there’s no reason for the universe to begin at the boundary condition. The laws of how systems evolve give how past and future relate (or more accurately, how the current system and the rate at which the current system changes relate). If you’re given what happens at t=0, you can calculate t=-1 just as easily as you can t=1. Intuitively, you’d say that t=0 caused t=1, and not the other way around. To the extent that that this is correct, the laws of system evolution do not preclude spontaneity. They only preclude future and past events not matching.
(I think I am having trouble considering the counterfactual, ‘imagine we had a universe where something could come from nothing’. Where should I start? Do somethings comes from nothing at any time t? Are there rules prescribing how things come from nothing?)
A simple example would be a psuedorandom number generator. For example, f(t) = f(t-1)^2 + 1. Thus, if f(0) = 0 (nothing at t=0), then f(1) = 1.
The only way to get out of boundary conditions is to define the whole universe in one step. For example, f(t) = t^3 + 3*t^2 + 1, in which case you wouldn’t have causality at all.
Suppose we run a cellular automaton simulation that initiates with some initial conditions and subsequently updates with a set of simple rules (e.g., like Newtonian mechanics or quantum mechanics or whatever) that sufficiently intelligent beings within the simulation could deduce and call ‘science’. Perhaps they could figure out they were in a simulation, and then everything in the simulation is their universe (there needn’t be any limits to the size of this universe) and everything outside it (of which they may know nothing) is outside it.
There are a few ways entities within the simulation could deduce a reality outside their own. First, any acausal inconsistencies in their physical laws, suggesting someone tampering with the simulation. Similarly, any truly random elements would mean outside influence—though it would be a challenging project to be certain that any elements were truly random (and acausal). Another way they could deduce they were in a simulation is the lack of an explanation for the beginning of the simulation—though again, it would be challenging to be certain that there is NO explanation rather than just an unknown one.
If the beings want to call our universe part of their universe due to these interactions of having initiated them, seeding random numbers and occasionally interfering, that is fine, but then they need to differentiate between their simulation in which their science applies and the encapsulating universe for which they don’t know what sort of rules apply.
Funny! When you get mail, such as this one, the envelope under your user name turns red until you check it. Yours is probably currently red.
I don’t mean how would it be different from not having an outside universe. I mean: how would our universe containing the reason that there is a universe be different than only their universe existing and containing the reason that there is a universe?
In other words, if you live in universe A, and either your universe exists for some reason you don’t understand, or it exists within universe B, which exists for some reason you don’t understand, why would the latter hypothesis be less confusing?
The latter hypothesis should in fact be more confusing; it’s isomorphic to the Creator’s creator problem.
I think this is a good question, and I wanted to think a while before replying. (My train of thought motivated some other comments in reply to this post.)
Our universe does look different than a universe containing an explanation for existence. The universe we imagined several centuries ago, with spontaneous generation occurring everywhere and metaphysical intervention at many different levels, had more room for such an explanation.
For now (at least until you dig down into quantum mechanics, which I know nothing about), the universe appears to be a mechanical clock, with every event causally connected to a preceding event. Nothing, nothing is expected to happen without cause—this appears to be a very fundamental rule of our current paradigm of reality.
Simultaneously, I observe that I cannot even imagine how it could be possible for something to exist without cause. On the one hand, this might just reflect a limit in my intuition, and existence without cause might be possible. On the other hand, I will present an argument that an inability to imagine something, and indeed finding it illogical, is evidence that it is not possible. (Well, it’s a necessary but not sufficient condition.)
My argument is that any actual limits in this universe will be inherited by simulations within this universe, including the mental ones we use to draw intuition and logic. Like a shape in flatland finding it impossible to imagine escaping from a ring, we cannot imagine spontaneous creation if it is not possible. (This is the argument that an impossible thing cannot be simulated or imagined. Whether our inability to imagine something implies it is impossible depends upon how flexible our minds are; I think our minds are very flexible but QM may be the first piece of evidence that we can’t grasp some things that are possible.)
But if we lived in the universe imagined centuries ago, where entirely natural things like flies and light spontaneously appeared from their sources, then we would have a chance to study spontaneity and see how it works. If spontaneity was possible, we could imagine it and simulate it and learn about it. But if spontaneity cannot occur here, we can’t collect any information about it and it stands to reason it would be mysterious. This is exactly what our universe looks like.
Imagine we had a universe where something could come from nothing. Imagine we worked out how to find what happens at t+1, given t. This still wouldn’t be enough to know everything. We’d have to know what’s going on at some t less than ours (or greater, if we can just figure out t given t+1).
In other words, even a universe with spontaneity still has to have boundary conditions. Nothing exists at t=0 is the most obvious boundary condition, and it’s probably the most likely one, but it’s not the only possible one. There’s no reason it has to be that one.
Incidentally, there’s no reason for the universe to begin at the boundary condition. The laws of how systems evolve give how past and future relate (or more accurately, how the current system and the rate at which the current system changes relate). If you’re given what happens at t=0, you can calculate t=-1 just as easily as you can t=1. Intuitively, you’d say that t=0 caused t=1, and not the other way around. To the extent that that this is correct, the laws of system evolution do not preclude spontaneity. They only preclude future and past events not matching.
I don’t yet follow.
Could you paraphrase your main thesis statement?
(I think I am having trouble considering the counterfactual, ‘imagine we had a universe where something could come from nothing’. Where should I start? Do somethings comes from nothing at any time t? Are there rules prescribing how things come from nothing?)
A simple example would be a psuedorandom number generator. For example, f(t) = f(t-1)^2 + 1. Thus, if f(0) = 0 (nothing at t=0), then f(1) = 1.
The only way to get out of boundary conditions is to define the whole universe in one step. For example, f(t) = t^3 + 3*t^2 + 1, in which case you wouldn’t have causality at all.