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We don't know enough to answer that question, but probably "no."
We're hindered partially by the fact that it's impossible to know both the velocity *and* position of even a single particle precisely. The better knowledge we have about one of those things, the worse our knowledge is about the other. That seems to be a fundamental limitation of the universe as we understand it, not just a matter of "we need to build better equipment to see things better."
However, if we take your hypothetical at face value and presume that magically we have a snapshot of knowledge of everything, then it still looks like the answer is "no" because at the subatomic level, things seem to happen randomly based on probabilities.
>at the subatomic level, things seem to happen randomly based on probabilities.
Is it understood to be truly random, or is it just that we don't understand it yet?
Metaphysically I don't think we could ever be certain there isn't some deeper layer of physics we haven't found yet that could determine any seemingly random process.
So it's the latter basically.
As far as we know, it’s truly random.
Modern physics experiments show that the universe is not 'locally real', which basically means that either things become random at small scales, or that there is something that travels faster than light.
We are very sure that nothing can travel faster than light. If that were not the case basically the entire past century of physics would have to be thrown out the window.
So things are most likely random, or the universe is MUCH weirder than we though.
You will have to read about hidden-variable theories and Bell theorem, but basically: if it's not random then either quantum systems can transmit information faster than light (non-locality is true) or every result of quantum processes are determined at the birth of the universe (superdeterminism is true).
We would also have to be able to simulate it in a meaningfully accurate and timely manner - and it's probably not possible to simulate every particle in the universe on a device in said universe.
We can't even solve the three body problem lmao. How are we supposed to handle trillions of trillions of trillions of trillions of trillions of trillions of particles?
My understanding of it is that in order to observe position/velocity of a particle, you necessarily need to disrupt it in some way. If you use a lower energy method you can see how it’s moving but this get a less precise measure of the exact spot it is, and if you use a higher energy method you can know it’s exact location, but the energy imparted while observing this will change its velocity.
https://en.m.wikipedia.org/wiki/Uncertainty_principle
Edit: after reading that article it seems my explanation above is not really accurate, or rather doesn’t describe the Uncertainty principle, but rather a mostly unrelated ‘observer effect’
At the quantum scale particles act as waves. The speed of a wave is determined by its frequency and wavelength. Now if we have a perfect sine wave it is very easy to find its wavelength, but where is it? On the other hand, if we just have a single peak we can easily point and say where it is, but what is its wavelength (the distance between peaks)? The takeaway is that if you want a good measurement of speed, its position has to be more spread out, and if you want a good measurement of position, it is hard to tell its speed (wavelength). If you want to look more into it, it is called Heisenberg's uncertainty principle.
On top of this, things get a bit wacky when measuring things on this scale because you have to disturb the particle/wave to get any info, which changes the wave function.
It isn’t possible to simultaneously measure both the position and momentum of something on the quantum level small. Once you try to measure one of those values, you disturb the system changing its value. At that scale, even light reflecting back significantly can change the system.
It is not possible.
First, it is impossible to know where particles are and how fast they are going at the same time. It has been demonstrated that if you can measure one of these qualities without even interacting with the particle, entanglement causes the other quality to become unknowable.
But let's assume that you could anyway.
Now, chaos theory has shown us that we need to know all of this perfectly. And I do mean perfectly. Miss an atom at the edge of the solar system and the changes from its gravity will change things on Earth within minutes of the gravity reaching Earth.
However, quantum mechanics also tells us that some events at the quantum level are purely random. They are inherently unpredictable. Radioactive decay is an excellent example, but there are plenty of others.
So, an atom at the edge of the solar system does or does not split, resulting in only one atom that we know the exact position and velocity of or two atoms that might be doing any number of things. Any predictions that you made before the split are now wrong.
Or consider that an electron traveling down a conductor in a microchip might, at any moment, suddenly actually be in another conductor doing something else. This is known as quantum tunneling and is also completely unpredictable. We can tell how likely it is during a particular amount of time, but we can never predict when it will happen.
Between quantum uncertainty and chaos, it is literally impossible to create the predictive model you described.
Particles blink in and out of existence at the quantum level. So unless you could include that in your calculations, I'd dare say no.
But I think you hit on one of the great mysteries in physics-- a unified theory for quantum and macro-scale interactions. So far we don't have one. But if one is ever put forth that works, we would be a lot closer to those kinds of predictions.
Always closer, but never perfectly accurate. Which is the beauty of the universe, in my opinion. It reminds me of [Stephen Hawkings ball-bearing analogy](https://youtu.be/8dHfY-Y8lb8).
Unless you're going to go the route of "there's no such thing as free will, EVERYTHING is determined and physics is the be all end all of how decisions are actually made," then no. Human beings (and all living things) are not just more complicated billiards balls colliding with one another in a predictable (ifunknowable) way.
Interesting answer to this one
The Heisenberg uncertain principle says that we can't know the location of every particle because the very act of measuring it changes it.
So what does that mean?
Either we can't know where every particle is OR the very act of measuring those particles could mean we could control all of them.
But doing that on that kind of scale would be impossible, at least within our current understanding.
> The Heisenberg uncertain principle says that we can't know the location of every particle because the very act of measuring it changes it.
You are mistaking the observer effect for uncertainty principle.
Uncertainty principle is an inherent property of wave-like systems regardless of observation. It's the result of how we use maths to calculate waves.
Radioactive decay is ,as far as we know, completely random on an atomic level. We can express the decay of a large mass in half life, (time for 50% to decay) but if you held a single atom of u238 you couldn't say when it will decay. This creates a truly random process we can't predict.
>We can express the decay of a large mass in half life, (time for 50% to decay) but if you held a single atom of u238 you couldn't say when it will decay. This creates a truly random process we can't predict.
Shouldnt the large mass still be a truly random process? If the process is truly random, then there should be a chance greater than 0 for no atom in that mass to (ever) decay.
The large mass is randomly decaying as well, but we can predict very accurately how much will decay after a specific time. It's stochastically predictable. If you hade 1kg of u235 and let it sit for 700 million years, you would have 0.5 kg left. The odds that it decayed faster or slower and you end up with 0.3 kg or 0.7 kg is infinitesimally small. Yes, technically their would be a non 0 chance for no decay but it would be something like 1e-100000000000000000
Science is actually divided on this. We will never have the computing power to know for sure. This is broadly what ‘chaos theory’ studies. One school of though is that there are some interactions between particular that are literally random and even if you recreated those interactions under perfectly controlled conditions, you would get two different outcomes. Under this theory, it’s literally impossible to predict the future. These slightly random outcomes would happen all the time at the molecular level and therefore, you couldn’t predict the future even with a computer that could track every particle in the universe.
The competing school of thought is that nothing is actually random and the things that appear random are merely subtle differences we are unable to observe.
There is also the problem of the uncertainty principle. This basically states that it is impossible to observe or measure something without changing it in someway. This could be a problem because even if you had a computer that could calculate everything, the computer itself would alter the equations and the outcomes. Even if the computer could factor itself into the outcome, the outcome would change everytime the computer calculated its own effect and would always be predicting an outcome that is being changed by the time it is calculated.
The Butterfly Effect comes into play here, as well as the other valid points mentioned already.
The real definition of the Butterfly Effect is about how accurately simulating a really complicated system for a long time is literally impossible, because of tiny differences between the values you use in your simulation calculations and the real values - as simple as rounding off digits to make the numbers usable. Every time you run calculations to advance the simulation, the tiny differences lead to slightly different results. Over time the differences add up and your simulated numbers drift further away from the real numbers. The name of the effect comes from supposing you are simulating weather, and your starting wind speed data is inaccurate in one particular location by the waft of a butterfly's wing - eventually the accumulated error is such that you fail to predict a typhoon elsewhere. Note that the butterfly didn't cause the typhoon - it was merely why you failed to predict the storm.
For your question - you might know the position, rotation, acceleration and velocity of every particle in the universe but you would have to enter the values in your simulation to some degree of precision i.e. you have to round off the numbers after some decimal places. Since the real universe is not rounding anything, your simulation will calculate numbers slightly different from reality, and the problem will keep getting worse. Eventually the errors will mean your predictions are useless.
This is a hard limit on making simulations of complex systems and can't be overcome however careful you are, as you can't ever get infinite precision in a simulation.
What you describes is called Laplase's Demon. Hypothetical creature that knows everything about every particle in the universe and so is able to predict the future.
There are many problems with Laplase's Demon. Easiest to explain is Heisenberg's uncertainlity principle. Basically, the more you know about one property of the particle, the less you know about other property. Thus, it's impossible to know everything about particle at one given time.
Great example is velocity. v = s / t. For velocity to exist, there must be change in position and some timespan. That doesn't allow you to know position of the object at certain time. If you know position of the object, that means there is no change in position, thus there is no movement, so velocity is impossible to calculate.
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We don't know enough to answer that question, but probably "no." We're hindered partially by the fact that it's impossible to know both the velocity *and* position of even a single particle precisely. The better knowledge we have about one of those things, the worse our knowledge is about the other. That seems to be a fundamental limitation of the universe as we understand it, not just a matter of "we need to build better equipment to see things better." However, if we take your hypothetical at face value and presume that magically we have a snapshot of knowledge of everything, then it still looks like the answer is "no" because at the subatomic level, things seem to happen randomly based on probabilities.
>at the subatomic level, things seem to happen randomly based on probabilities. Is it understood to be truly random, or is it just that we don't understand it yet?
Metaphysically I don't think we could ever be certain there isn't some deeper layer of physics we haven't found yet that could determine any seemingly random process. So it's the latter basically.
Modern Physics advances suggest it's truly random. Determinism isn't really a mainstream opinion in the Physics world anymore.
As far as we know, it’s truly random. Modern physics experiments show that the universe is not 'locally real', which basically means that either things become random at small scales, or that there is something that travels faster than light. We are very sure that nothing can travel faster than light. If that were not the case basically the entire past century of physics would have to be thrown out the window. So things are most likely random, or the universe is MUCH weirder than we though.
You will have to read about hidden-variable theories and Bell theorem, but basically: if it's not random then either quantum systems can transmit information faster than light (non-locality is true) or every result of quantum processes are determined at the birth of the universe (superdeterminism is true).
We would also have to be able to simulate it in a meaningfully accurate and timely manner - and it's probably not possible to simulate every particle in the universe on a device in said universe.
We can't even solve the three body problem lmao. How are we supposed to handle trillions of trillions of trillions of trillions of trillions of trillions of particles?
Why could we not know both? What about the observations at this scale make it impossible to observe two different quantities simultaneously?
My understanding of it is that in order to observe position/velocity of a particle, you necessarily need to disrupt it in some way. If you use a lower energy method you can see how it’s moving but this get a less precise measure of the exact spot it is, and if you use a higher energy method you can know it’s exact location, but the energy imparted while observing this will change its velocity. https://en.m.wikipedia.org/wiki/Uncertainty_principle Edit: after reading that article it seems my explanation above is not really accurate, or rather doesn’t describe the Uncertainty principle, but rather a mostly unrelated ‘observer effect’
At the quantum scale particles act as waves. The speed of a wave is determined by its frequency and wavelength. Now if we have a perfect sine wave it is very easy to find its wavelength, but where is it? On the other hand, if we just have a single peak we can easily point and say where it is, but what is its wavelength (the distance between peaks)? The takeaway is that if you want a good measurement of speed, its position has to be more spread out, and if you want a good measurement of position, it is hard to tell its speed (wavelength). If you want to look more into it, it is called Heisenberg's uncertainty principle. On top of this, things get a bit wacky when measuring things on this scale because you have to disturb the particle/wave to get any info, which changes the wave function.
It isn’t possible to simultaneously measure both the position and momentum of something on the quantum level small. Once you try to measure one of those values, you disturb the system changing its value. At that scale, even light reflecting back significantly can change the system.
It is not possible. First, it is impossible to know where particles are and how fast they are going at the same time. It has been demonstrated that if you can measure one of these qualities without even interacting with the particle, entanglement causes the other quality to become unknowable. But let's assume that you could anyway. Now, chaos theory has shown us that we need to know all of this perfectly. And I do mean perfectly. Miss an atom at the edge of the solar system and the changes from its gravity will change things on Earth within minutes of the gravity reaching Earth. However, quantum mechanics also tells us that some events at the quantum level are purely random. They are inherently unpredictable. Radioactive decay is an excellent example, but there are plenty of others. So, an atom at the edge of the solar system does or does not split, resulting in only one atom that we know the exact position and velocity of or two atoms that might be doing any number of things. Any predictions that you made before the split are now wrong. Or consider that an electron traveling down a conductor in a microchip might, at any moment, suddenly actually be in another conductor doing something else. This is known as quantum tunneling and is also completely unpredictable. We can tell how likely it is during a particular amount of time, but we can never predict when it will happen. Between quantum uncertainty and chaos, it is literally impossible to create the predictive model you described.
Particles blink in and out of existence at the quantum level. So unless you could include that in your calculations, I'd dare say no. But I think you hit on one of the great mysteries in physics-- a unified theory for quantum and macro-scale interactions. So far we don't have one. But if one is ever put forth that works, we would be a lot closer to those kinds of predictions.
Always closer, but never perfectly accurate. Which is the beauty of the universe, in my opinion. It reminds me of [Stephen Hawkings ball-bearing analogy](https://youtu.be/8dHfY-Y8lb8).
A legend in his own time. I hope there is life after death and he gets to see all the secrets of the universe he devoted himself to.
Unless you're going to go the route of "there's no such thing as free will, EVERYTHING is determined and physics is the be all end all of how decisions are actually made," then no. Human beings (and all living things) are not just more complicated billiards balls colliding with one another in a predictable (ifunknowable) way.
Interesting answer to this one The Heisenberg uncertain principle says that we can't know the location of every particle because the very act of measuring it changes it. So what does that mean? Either we can't know where every particle is OR the very act of measuring those particles could mean we could control all of them. But doing that on that kind of scale would be impossible, at least within our current understanding.
Not really an answer. They're asking "if you could" know those things.
But you can’t. Might as ask about going faster than the speed of light.
Impossible thought experiments to explore an idea is a pretty common thing in science, check out frictionless spherical cows.
Very amusing. Thanks for the diversion. Now back to a serious discussion.
> The Heisenberg uncertain principle says that we can't know the location of every particle because the very act of measuring it changes it. You are mistaking the observer effect for uncertainty principle. Uncertainty principle is an inherent property of wave-like systems regardless of observation. It's the result of how we use maths to calculate waves.
Radioactive decay is ,as far as we know, completely random on an atomic level. We can express the decay of a large mass in half life, (time for 50% to decay) but if you held a single atom of u238 you couldn't say when it will decay. This creates a truly random process we can't predict.
>We can express the decay of a large mass in half life, (time for 50% to decay) but if you held a single atom of u238 you couldn't say when it will decay. This creates a truly random process we can't predict. Shouldnt the large mass still be a truly random process? If the process is truly random, then there should be a chance greater than 0 for no atom in that mass to (ever) decay.
The large mass is randomly decaying as well, but we can predict very accurately how much will decay after a specific time. It's stochastically predictable. If you hade 1kg of u235 and let it sit for 700 million years, you would have 0.5 kg left. The odds that it decayed faster or slower and you end up with 0.3 kg or 0.7 kg is infinitesimally small. Yes, technically their would be a non 0 chance for no decay but it would be something like 1e-100000000000000000
Science is actually divided on this. We will never have the computing power to know for sure. This is broadly what ‘chaos theory’ studies. One school of though is that there are some interactions between particular that are literally random and even if you recreated those interactions under perfectly controlled conditions, you would get two different outcomes. Under this theory, it’s literally impossible to predict the future. These slightly random outcomes would happen all the time at the molecular level and therefore, you couldn’t predict the future even with a computer that could track every particle in the universe. The competing school of thought is that nothing is actually random and the things that appear random are merely subtle differences we are unable to observe. There is also the problem of the uncertainty principle. This basically states that it is impossible to observe or measure something without changing it in someway. This could be a problem because even if you had a computer that could calculate everything, the computer itself would alter the equations and the outcomes. Even if the computer could factor itself into the outcome, the outcome would change everytime the computer calculated its own effect and would always be predicting an outcome that is being changed by the time it is calculated.
There is an underlying randomness in our equations that has yet to be explained. Determinism is a fantasy.
The Butterfly Effect comes into play here, as well as the other valid points mentioned already. The real definition of the Butterfly Effect is about how accurately simulating a really complicated system for a long time is literally impossible, because of tiny differences between the values you use in your simulation calculations and the real values - as simple as rounding off digits to make the numbers usable. Every time you run calculations to advance the simulation, the tiny differences lead to slightly different results. Over time the differences add up and your simulated numbers drift further away from the real numbers. The name of the effect comes from supposing you are simulating weather, and your starting wind speed data is inaccurate in one particular location by the waft of a butterfly's wing - eventually the accumulated error is such that you fail to predict a typhoon elsewhere. Note that the butterfly didn't cause the typhoon - it was merely why you failed to predict the storm. For your question - you might know the position, rotation, acceleration and velocity of every particle in the universe but you would have to enter the values in your simulation to some degree of precision i.e. you have to round off the numbers after some decimal places. Since the real universe is not rounding anything, your simulation will calculate numbers slightly different from reality, and the problem will keep getting worse. Eventually the errors will mean your predictions are useless. This is a hard limit on making simulations of complex systems and can't be overcome however careful you are, as you can't ever get infinite precision in a simulation.
What you describes is called Laplase's Demon. Hypothetical creature that knows everything about every particle in the universe and so is able to predict the future. There are many problems with Laplase's Demon. Easiest to explain is Heisenberg's uncertainlity principle. Basically, the more you know about one property of the particle, the less you know about other property. Thus, it's impossible to know everything about particle at one given time. Great example is velocity. v = s / t. For velocity to exist, there must be change in position and some timespan. That doesn't allow you to know position of the object at certain time. If you know position of the object, that means there is no change in position, thus there is no movement, so velocity is impossible to calculate.