Heisenberg's Uncertainty Principle and determinism

In summary: One theory is called the Many Worlds Interpretation, which suggests that every possible outcome of a quantum event actually occurs in a separate universe, and that these universes are constantly interacting with each other.Another example is the De Broglie-Bohm theory, which suggests that particles do not have a definite location or momentum until they are observed, and that these observables (like momentum) are always correlated.
  • #1
riballoon
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TL;DR Summary
Hello everyone,

I was wondering if anyone had any insight to what Heisenberg's Uncertainty Principle says about (super)determinism?

Will determinism forever remain speculative?
As I understand it the principle states that the more accurately you measure one factor of an object, for example speed, the less you can tell of any other factors, for example position. To me this seems we will every only be able to measure an approximation of reality and thus determinism becomes unfalsifiable.

With all this said, I am but a lay enthusiast that barely passed math, so please, any and all insight would be greatly appreciated!

Thanks for your time,
-Riley
 
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  • #2
riballoon said:
As I understand it the principle states that the more accurately you measure one factor of an object, for example speed, the less you can tell of any other factors, for example position
First, that is NOT true for just any "other factors", it is only true of complementary characteristics such as position and momentum.

Second, it is not so much about single simultaneous measurements as it is about consistent measurements. What I mean is, in classical physics if you know EXACTLY the initial conditions / setup of an experiment, then you can be confident that the subsequent results of measuring complementary characteristics will always be the same. In Quantum Mechanics, what the HUP tells us is that if you know EXACTLY the initial conditions / setup of the experiment, then when you measure the complementary characteristics you not only do NOT know the what the results will be, you know in fact that they won't be the same over a series of measurements.
 
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To give a specific example, classical physics predicts that if you were to fire an electron with a precisely known velocity in a precisely known direction, then you could predict what the position and momentum of that electron would be a microsecond later. But in reality, what the HUP tells us that if you were to fire an electron with a precisely known velocity in a precisely known direction and then measure the position a microsecond later, then the more precisely you were to measure the position, the LESS precisely you would know the momentum. You could perform the same experiment over and over and depending on the precision with which you measured the position, you would get various values of the momentum as specified by the HUP limitations. **

** To be even more precise, you would get a range of the PAIR of values (position and momentum) as specified by the HUP limitations.
 
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As a further note, there are approximately 6.3 zillion threads here on PF about the HUP so you could do a forum search (but be warned, some of them will make your head hurt :smile:).
 
  • #5
Thanks for you reply! I didn't realize that distinction of complimentary characteristics vs "any" other factors.

So I guess my question becomes, how can one ever know the exact conditions of the setup if one can only measure, to the maximal degree, one of the complimentary characteristics? Will this still not lead to the approximation issue? It seems to me an infinite regress of how to set up exact conditions, especially since particles are not static and the only type of real measurement would be continuous observation?

If I've made some improper assumptions I'd love to know, this does confuse me if determinism turns out to be testable in any practical way.
 
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  • #6
riballoon said:
Summary: Hello everyone,

I was wondering if anyone had any insight to what Heisenberg's Uncertainty Principle says about (super)determinism?
It's clear what the Heisenberg UP says, but it's not clear what superdeterminism says. When superdeterminism has been discussed on here it seems everyone has their own idea about what the superdeterminists claim.

I would turn your question round, therefore, and ask what superdeterminism says about the HUP?
 
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  • #7
PeroK said:
I would turn your question round, therefore, and ask what superdeterminism says about the HUP?
Thanks for the question!

I don't necessarily think superdeterminism says anything for HUP except adding back local hidden variables, and taking away QM's probabilistic results.

I would think that only continuous monitoring of preset unaltering variables would be able to test for superdeterminism, otherwise how can you rule out that your hidden variables have changed from measurement 1 and 2? And how can that be set up in a practical way?
 
  • #8
riballoon said:
Thanks for the question!

I don't necessarily think superdeterminism says anything for HUP except adding back local hidden variables, and taking away QM's probabilistic results.
That's more what Bohmian mechanics does. That's a legitimate theory in the sense that it includes a full mathematical model.

In order to understand what SD (superdeterminism) says you must understand the concept of correlation, especially in respect of quantum entanglement. SD tries to explain the experimental results that support QM by proposing that all things are correlated in a way that falsely makes QM appear to be true. In that sense, a lot of physicists believe it's not even a valid theory and is possibly just sheer nonsense.

To give an example of a SD theory of gravity. That would suggest that there is no law of gravity. Instead, objects can fall upward or downward. But, we are correlated with them in such a way that whenever we release an object it falls downward. And experimenters are prevented from seeing objects falling upwards, not because they can't, but because their decision to release an object is correlated with the object's decision to go downwards. By this means the law of gravity simply appears to be true. And no one can prove otherwise.

And many people believe that approach to physics is nonsensical.
 
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PS I would refer you to Scott Aaronson for a sane view of superdeterminism from a quantum physicist. I agree with everything he says.

https://scottaaronson.blog/?p=6215
 
  • #10
PeroK said:
To give an example of a SD theory of gravity. That would suggest that there is no law of gravity. Instead, objects can fall upward or downward. But, we are correlated with them in such a way that whenever we release an object it falls downward. And experimenters are prevented from seeing objects falling upwards, not because they can't, but because their decision to release an object is correlated with the object's decision to go downwards. By this means the law of gravity simply appears to be true. And no one can prove otherwise.

I really don't see why you assume objects "decide" anything as opposed to react to the environment. If there is a sufficient gravitational pull, then the object will gravitate towards it. That does not mean the object chose to obey gravity.
 
  • #11
PeroK said:
SD tries to explain the experimental results that support QM by proposing that all things are correlated in a way that falsely makes QM appear to be true
This is essentially proposing hidden variables, no?
 
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  • #12
PeroK said:
And experimenters are prevented from seeing objects falling upwards, not because they can't, but because their decision to release an object is correlated with the object's decision to go downwards.
Do you propose that observers observe what the object "decides" to reveal, and not what actually is?
 
  • #13
riballoon said:
I really don't see why you assume objects "decide" anything as opposed to react to the environment. If there is a sufficient gravitational pull, then the object will gravitate towards it. That does not mean the object chose to obey gravity.
I was illustrating the absurdity of a SD theory of gravity. Not proposing one!
 
  • #14
riballoon said:
This is essentially proposing hidden variables, no?
No. Bohmian mechanics is a valid hidden variables. Superdeterminism is an unjustified and unsupported theory that asserts that QM only appears to be correct. In other words, as Scott Aaronson says, we have to ignore what experiment is telling us directly and trust the instincts of a few contrarians!

In one respect, superdeterminism is not that different from a capricious god!
 

Related to Heisenberg's Uncertainty Principle and determinism

1. What is Heisenberg's Uncertainty Principle?

Heisenberg's Uncertainty Principle is a fundamental principle in quantum mechanics that states that it is impossible to know both the exact position and momentum of a particle at the same time. This means that the more precisely we know the position of a particle, the less precisely we can know its momentum, and vice versa.

2. How does the Uncertainty Principle relate to determinism?

The Uncertainty Principle challenges the concept of determinism, which is the idea that the future state of a system can be determined by its current state and the laws of physics. Heisenberg's principle suggests that the very act of measuring a particle's position or momentum can affect its future behavior, making it impossible to predict with certainty.

3. Can the Uncertainty Principle be applied to macroscopic objects?

No, the Uncertainty Principle is only applicable to microscopic particles, such as electrons and photons. This is because the effects of quantum mechanics are only noticeable at the subatomic level, and macroscopic objects have enough mass and energy to overcome these effects.

4. How does the Uncertainty Principle impact our understanding of the physical world?

The Uncertainty Principle challenges our classical understanding of the physical world and highlights the limitations of our ability to observe and measure particles at the quantum level. It also suggests that there may be inherent randomness and unpredictability in the behavior of particles, which goes against the deterministic view of the universe.

5. Is the Uncertainty Principle a proven concept?

Yes, the Uncertainty Principle has been extensively tested and confirmed through numerous experiments and observations in quantum mechanics. It is considered a fundamental principle in this field and has been a crucial factor in the development of modern physics.

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