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Is there anyone present who understands this? I'd like to ask a question: My view on life is that it's deterministic. The mental analogy I've come up with is

Is there anyone present who understands this? I'd like to ask a question: My view on life is that it's deterministic. The mental analogy I've come up with is this: "If you were to roll a set of marbles down a hill, the outcome and trajectory would be identical no matter how many times you repeated the experiment given the same marble shapes and initial force." Where the marbles here are an analogy for our genetics, and the hill + initial force our environment. Reading the thought experiment it sounds like a similar analogy: > "Run a bath, then dump a bunch of floating bar magnets into the water. Each magnet will flip its orientation back and forth, trying to align with its neighbors. It will push and pull on the other magnets and get pushed and pulled in return. Now try to answer this: What will be the system’s final arrangement?" > "This problem and others like it, it turns out, are impossibly complicated." Can someone explain why this is "impossibly complicated?" Isn't it deterministic and calculable?

gostsamo 4y ago
Small differences in the initial conditions can bring big differences in the final result. This is the main postulate of chaos theory started with one Edward Lorenz and giving birth to stuff like the butterfly effect. https://en.wikipedia.org/wiki/Chaos_theory https://en.wikipedia.org/wiki/Chaos_theory
- omegalulw 4y ago
  This is part of the answer. The other part being that there seems to be fundamental non determinism in our universe.
  - seibelj 4y ago
    I agree - it is obvious to me that free will = non-determinism. But we are getting into metaphysics and unprovable thought experiments
  - bowsamic 4y ago
    Most likely but it depends on your interpretation of quantum mechanics. I believe in non determinism but that’s mainly a hunch
thechao 4y ago
https://en.wikipedia.org/wiki/Quantum_indeterminacy https://en.wikipedia.org/wiki/Quantum_indeterminacy This is similar to nondeterminacy, and is why we end up with all sorts of “interpretations” (Copenhagen, …). Indeterminacy makes the math really hard. I would like to say more, but I can’t do so and be correct. If you’re really interested, pick up all three volumes of “The Theoretical Minimum”, and come to your own opinion after learning the physics.
- bowsamic 4y ago
  Actually the probabilistic interpretations of quantum mechanics are far easier to use than the deterministic ones
pdonis 4y ago
> Isn't it deterministic and calculable? The classical version is deterministic, but "deterministic" does not necessarily mean "calculable". There are plenty of deterministic problems that are not calculable (at least not in any reasonable time frame, where "reasonable" means "not of a much greater order of magnitude than the age of the universe") because they are so sensitive to precise conditions that miniscule differences quickly become unmanageably huge. And since we can never measure a system's state to exact precision, nor can we calculate things to exact precision, our model of a system is always imprecise, and for many systems, "imprecise" means "not calculable" even though the underlying laws are deterministic. The quantum version is not even deterministic when measurements are involved.
- adastra22 4y ago
  There are interpretations of quantum mechanics in which it is deterministic as well (google search term: block universe).
  - pdonis 4y ago
    Yes, there are (the many worlds interpretation and the Bohmian "pilot wave" interpretation are the two that come immediately to mind). I don't see what that has to do with "block universe", however, since that is an interpretation of relativity, not quantum mechanics.
    - adastra22 4y ago
      We must be talking about different things. Block universe is the theory that the universe is fixed in advance (deterministic) as a 4 dimensional “block” (more dimensions to include many worlds, I suppose?) and we’re just exploring one probabilistic trace through it.
      - pdonis 4y ago
        Block universe, as a theory, is based on classical (non-quantum) relativity, and its model of 4-dimensional spacetime. It is not based on QM. Non-relativistic QM does not even use spacetime. Relativistic QM, aka quantum field theory, does use it, but is not a deterministic model and does not treat spacetime as fixed in the sense of all events within it being determined in advance. > we’re just exploring one probabilistic trace through it There is no such thing as a "probabilistic trace" through a deterministic 4-dimensional spacetime in which all events are fixed in advance.
zeusk 4y ago
Whenever you introduce fluids into this sort of experiment, any turbulent flow will add indeterminism to outcomes - this applies to air as well.
adastra22 4y ago
Deterministic, yes. Calculable, no, because you can never know the precise initial conditions, either for statistical mechanics reasons (classical) or uncertainty limits (quantum).
bowsamic 4y ago
There are three categories of theories relevant here: Deterministic classical mechanics Non deterministic interpretations of quantum mechanics (most popular among physicists) Deterministic interpretations of quantum mechanics (eg Bohmian mechanics) In the first case, the future is calculable in principle, but probably not in practise (too complex) In both of the other two cases, it is incalculable in principle, even though the latter is deterministic
- PeterWhittaker 4y ago
  You left out non-deterministic classical mechanics, e.g., Norton’s Dome: https://en.m.wikipedia.org/wiki/Norton%27s_dome https://en.m.wikipedia.org/wiki/Norton%27s_dome
dotancohen 4y ago
> Isn't it deterministic and calculable? Your quest for knowledge should include examining the Double Pendulum. It is an extremely simplified device, easily explained and understood, whose motion is chaotic. [1] https://en.wikipedia.org/wiki/Double_pendulum https://en.wikipedia.org/wiki/Double_pendulum

gostsamo 4y ago

Small differences in the initial conditions can bring big differences in the final result. This is the main postulate of chaos theory started with one Edward Lorenz and giving birth to stuff like the butterfly effect. https://en.wikipedia.org/wiki/Chaos_theory https://en.wikipedia.org/wiki/Chaos_theory

omegalulw 4y ago
This is part of the answer. The other part being that there seems to be fundamental non determinism in our universe.
- seibelj 4y ago
  I agree - it is obvious to me that free will = non-determinism. But we are getting into metaphysics and unprovable thought experiments
- bowsamic 4y ago
  Most likely but it depends on your interpretation of quantum mechanics. I believe in non determinism but that’s mainly a hunch

thechao 4y ago

https://en.wikipedia.org/wiki/Quantum_indeterminacy https://en.wikipedia.org/wiki/Quantum_indeterminacy This is similar to nondeterminacy, and is why we end up with all sorts of “interpretations” (Copenhagen, …). Indeterminacy makes the math really hard. I would like to say more, but I can’t do so and be correct. If you’re really interested, pick up all three volumes of “The Theoretical Minimum”, and come to your own opinion after learning the physics.

bowsamic 4y ago
Actually the probabilistic interpretations of quantum mechanics are far easier to use than the deterministic ones

pdonis 4y ago

> Isn't it deterministic and calculable? The classical version is deterministic, but "deterministic" does not necessarily mean "calculable". There are plenty of deterministic problems that are not calculable (at least not in any reasonable time frame, where "reasonable" means "not of a much greater order of magnitude than the age of the universe") because they are so sensitive to precise conditions that miniscule differences quickly become unmanageably huge. And since we can never measure a system's state to exact precision, nor can we calculate things to exact precision, our model of a system is always imprecise, and for many systems, "imprecise" means "not calculable" even though the underlying laws are deterministic. The quantum version is not even deterministic when measurements are involved.

adastra22 4y ago
There are interpretations of quantum mechanics in which it is deterministic as well (google search term: block universe).
- pdonis 4y ago
  Yes, there are (the many worlds interpretation and the Bohmian "pilot wave" interpretation are the two that come immediately to mind). I don't see what that has to do with "block universe", however, since that is an interpretation of relativity, not quantum mechanics.
  - adastra22 4y ago
    We must be talking about different things. Block universe is the theory that the universe is fixed in advance (deterministic) as a 4 dimensional “block” (more dimensions to include many worlds, I suppose?) and we’re just exploring one probabilistic trace through it.
    - pdonis 4y ago
      Block universe, as a theory, is based on classical (non-quantum) relativity, and its model of 4-dimensional spacetime. It is not based on QM. Non-relativistic QM does not even use spacetime. Relativistic QM, aka quantum field theory, does use it, but is not a deterministic model and does not treat spacetime as fixed in the sense of all events within it being determined in advance. > we’re just exploring one probabilistic trace through it There is no such thing as a "probabilistic trace" through a deterministic 4-dimensional spacetime in which all events are fixed in advance.

zeusk 4y ago

Whenever you introduce fluids into this sort of experiment, any turbulent flow will add indeterminism to outcomes - this applies to air as well.

adastra22 4y ago

Deterministic, yes. Calculable, no, because you can never know the precise initial conditions, either for statistical mechanics reasons (classical) or uncertainty limits (quantum).

bowsamic 4y ago

There are three categories of theories relevant here: Deterministic classical mechanics Non deterministic interpretations of quantum mechanics (most popular among physicists) Deterministic interpretations of quantum mechanics (eg Bohmian mechanics) In the first case, the future is calculable in principle, but probably not in practise (too complex) In both of the other two cases, it is incalculable in principle, even though the latter is deterministic

PeterWhittaker 4y ago
You left out non-deterministic classical mechanics, e.g., Norton’s Dome: https://en.m.wikipedia.org/wiki/Norton%27s_dome https://en.m.wikipedia.org/wiki/Norton%27s_dome

dotancohen 4y ago

> Isn't it deterministic and calculable? Your quest for knowledge should include examining the Double Pendulum. It is an extremely simplified device, easily explained and understood, whose motion is chaotic. [1] https://en.wikipedia.org/wiki/Double_pendulum https://en.wikipedia.org/wiki/Double_pendulum