Determining the future

[Wictorian]

Given that we have access to everything like locations and speeds of every single atom and subatomic particle, would it be possible to determine the future?

 

If so, woudln’t it create a paradox? If we had seen a negative event, we would prevent it and wouldn’t see it in the first place.

[Guest]

13 minutes ago, Wictorian said:

Given that we have access to everything like locations and speeds of every single atom and subatomic particle, would it be possible to determine the future?

Are those time traveling particles?

Do those particles hold information from the future?

How will you access said information, if it exists? How will you interpret it?

[tikker]

15 minutes ago, Wictorian said:

Given that we have access to everything like locations and speeds of every single atom and subatomic particle

We don't.

15 minutes ago, Wictorian said:

would it be possible to determine the future?

To a certain extent. This is what weather forecasts, spacecraft launch estimations, orbit calculations, simulating galaxy mergers etc. all do in essence. They predict the future based on our current knowledge. We don't have any future knowledge however. It's all based on past interactions, positions and theories of how things work.

15 minutes ago, Wictorian said:

If so, woudln’t it create a paradox? If we had seen a negative event, we would prevent it and wouldn’t see it in the first place.

The paradox is mostly if not completely resolved by the previous fact that we don't know with certainty that our prediction is correct until it has happened. We can't make predictions of the truthseer kind like "in 2050 Canada will invade the US", but we can do predictions like "we see a hurricane develop and we're X% sure it will hit city Y in 3 days, so start taking preventive measures".

[harryk]

In principle yes we could predict everything but in reality there are certain phenomena in physics which inhibit this.

 

The classic textbook example is the double pendulum.

 

In terms of mechanical systems, the double pendulum is quite simple and is governed by the fundamental equations of motion. So on paper (or rather with code) it is easy to model the motion and behavior of the double pendulum. However, it quickly becomes apparent that the motion is highly dynamic and extremely sensitive to the initial conditions. A slight change in the initial position yields a completely different state some time later. 

 

If it's extremely sensitive to the initial conditions, all we have to do is better measure them. In principle if we knew the exact position and velocity of every atom, then there is no reason we couldn't accurately predict the motion of the larger pendulum. We understand the basic equations of motion after all. 

 

Introduce the Heisenberg uncertainty principle, a fundamental piece of quantum mechanics. As defined by the uncertainty principle there is a fundamental limit to the accuracy we can measure the physical properties of particles. We can measure the position of a particle very accurately, but not the momentum. Or we can measure the momentum very accurately, but not the position. We can never know both with a high level of accuracy. 

 

Thus our knowledge of the initial state of the double pendulum is fundamentally limited, so our ability to predict its motion is ultimately also limited. This behavior is encompassed by the chaos theory. For systems which are highly sensitive to the initial conditions, later states are effectively random and unpredictable.

[Queen Chrysalis]

Y'all just learn ya some predeterminism or something? (Neural networks, synapses, endocrine system, predictable stimuli) 

 

If that's where this is headed, note that despite this theory seeming kosher enough, and the concept of free will seemingly getting 86'd by it, when people are primed to believe that they have some kind of free will or choice, they have shown do exhibit more prosocial behavior than when they are not.  Therefore, whether predeterminism true in some abstract way or not (I think it probably is) it's better for society to ignorantly believe in free will anyway.  I took the same approach to how I thought about God a while ago, despite being atheist for a while, and still subconsciously not really being sold on the concept of divinity.

[Helpful Tech Witch]

No.

the act of recording the information, if you could ignore basic laws of physics (like the speed of light, or whatever), to instantly get the data and use it before the data is useless (and instantly process it), you would change the positions of the particles

Plus i believe heisenburgs uncertainty principle covers this pretty well, if you measure the velocity, you change the position, and if you measure the position, you change the velocity, so you would need to just supernaturally know, otherwise you’d end up just having half the date, unless you could, like I said, instantaneously just know and process it. To get directions, speed, the type of particle, etc, you would change most of the others finding one

[Eigenvektor]

17 hours ago, Wictorian said:

Given that we have access to everything like locations and speeds of every single atom and subatomic particle

Every particle in the universe? Never going to happen. Even if you only store two bits of information for a particle, and you could hold a bit of information in a single particle, you'd require twice the amount of particles to store that information. Except you now need twice as many again, to include information about your information storing particles … How's that for a paradox?

 

Then there's the problem that possible interactions between these particles would take an unimaginable amount of computational power to predict. What's the point of predicting the future, if the computation takes so long the future has long since turned into the past by the time you're done? Plus all of those electrons flowing through your computer during the calculation would influence the result, because e.g. their electromagnetic field would, however weak, influence things ever so slightly which could then over time have a larger effect on things.

 

As others have already mentioned, there's also the Heisenberg principle that states you can either determine position or velocity of a particle but never both at the same time. So your predictive model could never include everything there is to know.

[Wictorian]

4 hours ago, Helpful Tech Wiard said:

No.

the act of recording the information, if you could ignore basic laws of physics (like the speed of light, or whatever), to instantly get the data and use it before the data is useless (and instantly process it), you would change the positions of the particles

Plus i believe heisenburgs uncertainty principle covers this pretty well, if you measure the velocity, you change the position, and if you measure the position, you change the velocity, so you would need to just supernaturally know, otherwise you’d end up just having half the date, unless you could, like I said, instantaneously just know and process it. To get directions, speed, the type of particle, etc, you would change most of the others finding one

You can’t resolve the paradox by saying it is impossible…

[Wictorian]

3 hours ago, Eigenvektor said:

Then there's the problem that possible interactions between these particles would take an unimaginable amount of computational power to predict. What's the point of predicting the future, if the computation takes so long the future has long since turned into the past by the time you're done? Plus all of those electrons flowing through your computer during the calculation would influence the result, because e.g. their electromagnetic field would, however weak, influence things ever so slightly which could then over time have a larger effect on things.

I have thought about this but I am not entirely sure that it is impossible to optimise it. The compıter itself would be included in the data too.

 

And again you can’t resolve it by assuming it is impossible.

 

 

[Eigenvektor]

7 hours ago, Wictorian said:

I have thought about this but I am not entirely sure that it is impossible to optimise it. The compıter itself would be included in the data too.

To simulate the universe, first, build the universe. Then make it run at twice the speed...

 

As I have said: Even if you could optimize your machine to a level where you only need two bits of information per particle and each bit requires a single particle, you still require two particles for every particle you want to store information about. No amount if optimization is going to solve this. In reality you'd require many more bits and particles per particle.

 

Of course you could say the universe itself is the computer and every particle stores its own information and the interaction of these particles is the computation. Which means the computation result is available in real time. You're simply unable to predict anything before it happens.

 

Scientist have found a way though: By observing the universe, we've been able to come up with hypothesis and theories, run experiments and tests that do allow us to predict future events (with a certain amount of probability).

 

7 hours ago, Wictorian said:

And again you can’t resolve it by assuming it is impossible.

I'm not merely assuming it's impossible to know the location and speed of every single atom and subatomic particle. I've provided a simple logical explanation as to why it is so. However, you don't even need this much information to predict future events, as long as you're willing to accept a certain amount of uncertainty.

 

Weather forecasts don't need to take each and every particle into account to predict what the weather is going to be like. Of course its not 100% accurate, precisely because there are things we don't know yet and/or there are small details we didn't take into account. The amount of computation needed to give more precise results would be so large, you wouldn't know the result until it no longer matters.

 

On 3/5/2022 at 2:40 PM, Wictorian said:

If so, woudln’t it create a paradox? If we had seen a negative event, we would prevent it and wouldn’t see it in the first place.

The fuel gauge of my car predicts I'm going to run out of fuel in 5 km. I drive into a gas station and refuel it, thus preventing this negative event from happening. How is this a paradox? Thanks to science we know the Sun is going to run out of fuel in roughly 5 billion years. If we figure out how to prevent this from happening, is this now a paradox?

 

It is only a paradox if you accept that the future is predetermined. Going back into the past to alter an event that alters the "now" is a paradox, because "now" is a future that has already come to pass. Doing something today that affects tomorrow is not a paradox, precisely because tomorrow hasn't happened yet.

[Wictorian]

Spoiler

4 hours ago, Sakuriru said:

That's an excellent question! This was also postulated some time ago as Laplace's demon. In the framework of current theory of everything: not with perfect accuracy and this has been discussed above in depth.

 

I can offer some greater insight on this since cosmology and specifically speculative quantum theories is a hobby of mine. One of the first approaches to this sort of realm is the application of what's called the Allegory of the cave. In more digestible terms, what we perceive and perhaps more important, understand, could be thought of as simply a description of shadows of what is actually real, and not the true nature of things. I will take a page from the philosophical school of skepticism and cast doubt on our understanding of the current theories of everything.

 

Our understanding of the Universe around us, and especially the world of atoms, is based on models that we have derived from experimentation. These models give us predictive power, which is what gives them validity. The Schrödinger equation has mathematical elegance and strong predictive power, general relativity accurately describes how space and time are inseparable and how it functions with concern to gravity, and the Heisenberg uncertainty principle puts constraints on what can be knowable. However, these are only theories and models which only describe phenomenon and are not the rules for these phenomenon: an important distinction when dealing with the sort of philosophical question asked; none of these models or theories have power over the true nature of reality.

 

There certainly could be, and very likely is, a correct model of reality which has better predictive power than what we understand in the standard model, and will solve the quantum gravity problem. But an important note is that even our best physics can't accurately account for everything we have perceived (e.g., the link between general relativity and quantum mechanics), so the jury isn't even close to being out on what is possibly knowable.

 

In short, the Universe could still be 100% deterministic and the random processes we see are not truly random, but are simply not understood. This statement would still be valid even if we had access to all knowable information, since there is always the possibility that there is information that is unknowable. But even if we were to generalize Laplace's demon to be "Can all knowable information be used to predict the future accurately?", we would find ourselves at an impasse: all information may be knowable, or not.

 

In other words, the question asked is not answerable.

 

This is all very esoteric, so for a more specific and concrete answer you may find it helpful I personally prefer the Many-worlds interpretation. In adapting to this question, without a way to know which of the many worlds you would branch to, the future is not predictable.

 

So in the end my question boils down to whether the universe is deterministic or not? I think it is safe to assume it is, for the sake of our paradox. Maybe you think this level of assuming is not healthy but what we are searching for is not necessarily the absolute truth, but the truth under certain circumstances. 
 

The best thing I have came up with is the computer needs the data of the results too and as it is impossible to get them before we have them, we can’t predict the future.

 

Edit: We can predict events like sun’s death but we can’t predict our influence so it doesn’t make a paradox
 

 

Edited March 7, 2022 by Wictorian

[wasab]

At the quantum level, everything is a probability. E.g. you can never pinpoint the exact location of an electron for example, only where it might be and to what likelihood at any given time. An electron can in fact be at more than one place simultaneously. There are also many weird things going on. E.g. a quantum particle can behave both like a wave and matter, it all depends on in what ways you observe it. 

 

In this regard, I don't think you can predict everything even if you are an omniscient God who knows all. 

[Wictorian]

14 hours ago, Sakuriru said:

I think that if you're going to assume the Universe is deterministic then the question is still unanswerable, since there may be factors at work which are unknowable (e.g., Heisenberg uncertainty).  On this note, however, we do seem to have great predictive power with our model of physics, and we do in fact simulate systems on atomic scales.

 

Additionally the Universe may only be deterministic in the scale of many worlds, but if I wanted to give you a reason why we couldn't with 100% certainty predict something on large scales from a frame of reference then look no further than Shcrödinger's box. Since macroscopic events (i.e., cat's death) is determined by the wave function collapse, it is possible to hook up much larger systems to this kind of experiment. Suppose you had a sun-destroying weapon with a firing mechanism hooked into the radioactive decay of an atom. The effects of such a small, and as far as we know unpredictable, change would alter the world on a cosmic level. I believe this is a compelling reason why you cannot dismiss quantum phenomenon when attempting to accurately predict the Universe.

How do many worlds make the universe deterministic though? Based on intuition I’d guessed it would do the opposite.

[tikker]

On 3/7/2022 at 7:33 AM, Sakuriru said:

However, these are only theories and models which only describe phenomenon and are not the rules for these phenomenon: an important distinction when dealing with the sort of philosophical question asked; none of these models or theories have power over the true nature of reality.

 

Our description of things can be seen as the rules of that phenomenon though. The only thing we can't do is prove that they are the rules that govern it. That leads to "the truth" being that which we cannot yet disprove. In the cave, one could come up with a theory that does describe the figures as being created from objects in front of a light source. Without a means to exit the cave, however, that would never be verifiable other than seeing predictions match up, which is why we like predictive power in a proper theory.

On 3/7/2022 at 3:50 PM, Sakuriru said:

Additionally the Universe may only be deterministic in the scale of many worlds, but if I wanted to give you a reason why we couldn't with 100% certainty predict something on large scales from a frame of reference then look no further than Shcrödinger's box. Since macroscopic events (i.e., cat's death) is determined by the wave function collapse, it is possible to hook up much larger systems to this kind of experiment. Suppose you had a sun-destroying weapon with a firing mechanism hooked into the radioactive decay of an atom. The effects of such a small, and as far as we know unpredictable, change would alter the world on a cosmic level. I believe this is a compelling reason why you cannot dismiss quantum phenomenon when attempting to accurately predict the Universe.

That nicely illustrates a subtelty in many formulations such as radioactive decay: they describe the macroscopic behaviour of a collection of particles and not the individual ones themselves. In conjunction with the above, even though we can't predict when an individual atom will decay, we still see that on a macroscopic scale radioactive matter does nicely follow "the rules" that we have determined. Funnily enough Schrödinger's cat was meant to show the ridiculousness of superposition states. The many worlds theory, to my knowledge, fixes that paradox by creating separate timelines where each outcome happens. If we observe the cat to be alive, then another timeline exists where it is dead. It is interesting to think about how quantum effects could have influenced us in the early stages of the Universe where it would be most powerful though

 

13 hours ago, Wictorian said:

How do many worlds make the universe deterministic though? Based on intuition I’d guessed it would do the opposite.

Deterministic and predictable are separate things. In a deterministic system the next state depends on the previous state. In that sense the Universe can be said to be deterministic, as what happens in the next billion years depends on what happened in the last billion years. The problem for us is is determining the initial conditions to sufficient accuracy, just like with the double pendulum. If we can't do that then we essentially have an unpredictable yet deterministic system.

[carnex]

On 3/5/2022 at 2:40 PM, Wictorian said:

Given that we have access to everything like locations and speeds of every single atom and subatomic particle, would it be possible to determine the future?

 

If so, woudln’t it create a paradox? If we had seen a negative event, we would prevent it and wouldn’t see it in the first place.

Short answer, we don't know if we could determine the future. Our knowledge is so limited tat we have no idea. And plenty ow knowledge we have is limited to predicting outcome not why those outcomes occur.

Remember. Paradoxes are just limitations of our reasoning and knowledge, not glitches in the system.

[Wictorian]

11 hours ago, tikker said:

Deterministic and predictable are separate things. In a deterministic system the next state depends on the previous state. In that sense the Universe can be said to be deterministic, as what happens in the next billion years depends on what happened in the last billion years. The problem for us is is determining the initial conditions to sufficient accuracy, just like with the double pendulum. If we can't do that then we essentially have an unpredictable yet deterministic system.

What I meant is if the many worlds theory is true then the future doesn’t really at least solely depemd on initial conditions thus it’s not deterministic.

[Wictorian]

11 hours ago, carnex said:

Remember. Paradoxes are just limitations of our reasoning and knowledge, not glitches in the system.

I don’t think so, unless the paradoxes really take place, then obviously the existence of the paradox would be impossible.

[tikker]

4 hours ago, Wictorian said:

What I meant is if the many worlds theory is true then the future doesn’t really at least solely depemd on initial conditions thus it’s not deterministic.

The many worlds theory is deterministic. You can illustrate that with Schrodinger's cat experiment again. If you set it up, two timelines will be created: one with an alive cat and one with a dead cat. If you don't set it up, no such timelines would be created. Of course there would also be two timelines each where you do and don't set it up, but what happens next still depends on what happened before.

4 hours ago, Wictorian said:

I don’t think so, unless the paradoxes really take place, then obviously the existence of the paradox would be impossible.

There are plenty of paradoxes that aren't really paradoxes, the twin paradox is a classic example and is caused by not accounting for acceleration (i.e. a lack of understanding). Other paradoxes can't happen (to our knowledge), like the grandfather paradox. It would be problematic if you went back in time and killed your grandfather, but since you can't travel back in time the paradox is only a philosophical one (until we figure out time travel).

[Wictorian]

30 minutes ago, tikker said:

The many worlds theory is deterministic. You can illustrate that with Schrodinger's cat experiment again. If you set it up, two timelines will be created: one with an alive cat and one with a dead cat. If you don't set it up, no such timelines would be created. Of course there would also be two timelines each where you do and don't set it up, but what happens next still depends on what happened before.

My question is, can you determine which timeline you will end up in?

[tikker]

1 hour ago, Wictorian said:

My question is, can you determine which timeline you will end up in?

There you see the difference between deterministic and predictable again. When you open the box you will find a cat. Wheter it's alive or dead will depend on the timeline you entered, which to my knowledge isn't something we can predict so far.

[Wictorian]

On 3/9/2022 at 3:42 PM, tikker said:

There you see the difference between deterministic and predictable again. When you open the box you will find a cat. Wheter it's alive or dead will depend on the timeline you entered, which to my knowledge isn't something we can predict so far.

Thanks now I feel like I kinda get it.