# Questions tagged [determinism]

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### Flipping a coin with same initial conditions

Today, in my physics class my teacher was talking about how we can never predict the outcome of a coin flip. So I thought: Will the outcome of a coin flip be the same if we do not change the initial ...
0answers
124 views

### Is Gerard 't Hooft's Cellular Automaton Interpretation of Quantum Mechanics background independent?

In Gerard 't Hooft in his Cellular Automata Interpretation of Quantum Mechanics (https://www.researchgate.net/publication/...
2answers
37 views

### Can a perfectly symmetrical round bead dropped into a perfectly level Galton Board indefinitely balance on a peg?

Probability implies that "The Galton Board consists of a vertical board with interleaved rows of pegs. Beads are dropped from the top and, when the device is level, bounce either left or right as they ...
0answers
38 views

### Block universe and quantum mechanics [duplicate]

Can a block universe (complete determinism) ever be compatible with quantum mechanics?
1answer
81 views

### Quantum mechanics limits to understanding the Universe [closed]

By definition, a wave function does not describe a particle's state exactly, we can only know that information when we make measurements and thus collapse the wave function. This gives us a lot of ...
1answer
91 views

### Quantum Mechanics - How do we know that the observed locations of electrons are random? [duplicate]

How do we know that the observed location of a electron (or any quantum object) is purely random (there is no way to predict it) within the probability-function instead of normal randomness (we don't ...
0answers
22 views

### Question reg. reasoning of deterministic reversible cyclical laws - The Theoretical Minimum

I recently started reading "The Theoretical Minimum: What you need to know to start doing Physics". In the first chapter, the authors define the "Minus-First law", and state that reversible ".. laws ...
5answers
5k views

### Is throwing dice a stochastic or a deterministic process?

As far as I understand it a stochastic process is a mathematically defined concept as a collection of random variables which describe outcomes of repeated events while a deterministic process is ...
1answer
52 views

### Are there theories or experiments involving multi variable particles?

Every hidden variable/entanglement experiment I’ve ever heard described involves ONLY one variable of either polarization or spin. Therefore Venn calculations backed by diagrams highlight the ...
0answers
66 views

### How do you determine the path of a particle placed in a vector field?

I have recently found a way of expressing newtonian gravity as a vector feild. First the Equation $$F=\frac{Gm_1m_2}{r^2}$$ I only want to know the accelleration in the equation since I only want to ...
1answer
45 views

### How can the whole path of a particle be determined by its configuration at any time and the rate of change of configuration at that time?

In the image, it says the whole path can be determined by knowing u(t1) and u'(t1) at any point t1. As far as I know, using u(t1) and u'(t1), the best we can do is approximate a nearby point u(t1+del ...
1answer
57 views

### Non deterministic quantum gates

There are situations (e.g. in quantum optics) where local non-unitary operators can be defined. In these cases, people say that the operation is non-deterministic. Could you please clarify how the ...
1answer
82 views

### How did Big Bang determine the initial conditions of the universe?

My question is that how did the Big Bang determine the initial distribution of the particles and their wavefunctions? In theories like Bohmian mechanics or Many worlds, how was the universal ...
2answers
369 views

### If $A^\mu$ is not determined uniquely by Maxwell's equations, what happens if we solve for it numerically?

Given a solution $A^{\mu}(x)$ to Maxwell's equations \begin{equation} \Box A^{\mu}(x)-\partial^{\mu}\partial_{\nu}A^{\nu}=0\tag{1} \end{equation} which also satisfies some specified initial conditions ...
2answers
90 views

### Does retro-causality imply unpredictability?

In some interpretations of Quantum mechanics (e.g. transactional interpretation), the future affects present. Is this a source of unpredictability in such interpretations, which makes them have the ...
3answers
2k views

### Predicting the future [duplicate]

In the special theory of relativity, each event is a point in 4d spacetime. And we can represent our life as a world line in the spacetime. Then, if we somehow find out the mathematical equation of ...
1answer
85 views

### Unpredictability, per definitions of chaotic behavior

Apparently I've been confused about the meaning(s) of "chaotic behavior". I always thought it meant that infinitesimal perturbations of a system parameter would lead to large changes in the system's ...
2answers
238 views

### Does quantum randomness exist? [duplicate]

I just want to know if the quantum world is random. Or if the randomness is fully explained by measurement error. Or if it is just semantic. The previous questions are open to interpretation and do ...
2answers
160 views

### Why does information loss in quantum collapse not threaten determinism?

When Hawking argued that information is lost in black holes, this triggered the "black hole war" because it threatened determinism, which would mean the laws of physics are only true on average. But ...
1answer
163 views

### How does the black hole information paradox threaten quantum determinism?

I was surprised by the subtitle of Susskind’s Black Hole War: My Battle with Stephen Hawking to Make the World Safe for Quantum Mechanics. I would have expected that information loss would violate ...
7answers
4k views

### How can a particle's position be random and uncertain in quantum mechanics if it is already pre-determined in relativity?

In relativity, to my knowledge, the path of an object is described by its worldline in spacetime, and since time is a part of the spacetime geometry, an object's worldline--in a sense--always exists ...
14answers
2k views

### How can the solutions to equations of motion be unique if it seems the same state can be arrived at through different histories?

Let's assume we have a container, a jar, a can or whatever, which has a hole at its end. If there were water inside, via a differential equation we could calculate the time by which the container is ...
1answer
85 views

### What do physicists mean when they say QM proves randomness?

Some physicists like Michio Kaku has said that the physics has proven randomness. Even some of my friends(they're not physicists) cite the Delayed Choice Quantum Eraser experiment and entanglement to ...
1answer
138 views

### Why do the laws of physics fail to predict the behavior of frustrators? [closed]

This is my attempt to make an earlier question less broad. This question takes the form of a thought experiment, and is based on this video. Suppose you are given: The positions, velocities, ...
0answers
106 views

### Why are there limits on physics' applicability? [closed]

(Not sure if this is the right SE for this question). Physics is great at predicting what inanimate stuff do. Why can't it also predict what living things do? For example, if I throw a ball off a ...
0answers
78 views

### Is the Many-Worlds Interpretation consistent with our best understanding of time? [closed]

Einstein's theory of relativity implies a B-theory of time. Deterministic interpretations of quantum mechanics such as the Many-Worlds would seem to be consistent with the B-theory. Regardless of ...
0answers
139 views

### Newton's Principle of Determinacy (intuitive explanation)

I was reading Arnold's Mathematical Methods of Classical Mechanics. In it he speaks of "Newton's Principle of Determinacy". He says for a mechanical system (collection of point masses in 3D Euclidean ...
1answer
68 views

### Randomness - Quantum Mechanics

If there is pure probabilistic randomness for quantum particles, why isn't this randomness seen in macroscopic objects too, after all they are made up of quantum particles? Why and How does this ...
1answer
128 views

### Could the apparent non-determinism of Quantum Mechanics be explained with a universal pseudo-random number generator? [closed]

As a thought experiment, would it be logically plausible to claim that the apparent randomness of Quantum Mechanics could be explained by the existence of a universal and deterministic pseudo-random ...
1answer
2k views

### What situations in classical physics are non-deterministic?

In Sean Carroll's book "The Big Picture," he states (chapter 4, page 35): Classical mechanics, the system of equations studied by Newton and Laplace, isn't perfectly deterministic. There are ...
1answer
71 views

### Distinguish Definitions: Realism Scientific, Realism, and realistic

I was readying about study about bell's theorem, where I had the question about some definitions. Here's some of my summaries: Scientific Realism: (https://en.wikipedia.org/wiki/Scientific_realism#...
0answers
38 views

### How deterministic nature of our world emerges?

Quantum mechanics shows that nature is non-deterministic. But the world we see around us seems deterministic. Take for an example: harmonic oscillator when $n$ becomes very large the probability ...
9answers
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### What exactly is deterministic in Schrödinger's equation?

I have read the following on Wikipedia but I can't understand it: In quantum mechanics, the Schrödinger equation, which describes the continuous time evolution of a system's wave function, is ...
1answer
55 views

### What determines the determinism of observables?

It is well known that there exists certain class of physical observables like momentum and position which are common to both classical and quantum mechanics, and has different 'kinds of predictability'...
1answer
209 views

### From locality to deterministic hidden variables

According to this link here Bell said: "My own first paper on this subject ... starts with a summary of the EPR argument from locality to deterministic hidden variables. But the commentators have ...
2answers
699 views

### Is the future predetermined and fixed? [closed]

I just watched a YouTube video which explained that life as a sequence of events is a geometric object in the four-dimensional spacetime and that the future is not only predetermined, but it already ...
4answers
873 views

### Causes and Effects in the quantum world [closed]

I am debating with a person about questions of causes and effects in the quantum world, and some questions came into our minds, hence I would be very happy to know what is "your opinion" that is, what ...
3answers
157 views

### How can we certify that the randomness in the measurement outcomes is not due to randomness in the state preparation?

According to the theory of quantum mechanics, if a spin state is prepared along axis "x", and then measured along axis "z", then the result of the spin projection is probabilistic: half of the times ...
1answer
377 views

### Does relativity of simultaneity prove determinism? [closed]

Does relativity of simultaneaty imply determinism? Let's say an alien in a distant part of the universe travels towards us at a certain speed at this moment(i.e. from our perspective that alien is ...
1answer
90 views

### Unitarity of Quantum Mechanical Systems

I was reading this lecture notes "Black holes from A to Z" by Andrew Strominger. In the first chapter Introduction the following statement is made: "If we know the present, there are laws that ...
1answer
52 views

### How do you know the classical deterministic past when particles bind?

Firstly, this is assuming a classical mechanics approach as outlined in Leonard Susskind's theoretical minimum (first lecture). In a classical setting assuming no quantum effects, how do you tell the ...
1answer
65 views

### Is a future event fixed by happening of past events?

If i say an event as an outcome of past events and those past events as outcomes of earlier events. I can also say that an event generates future event. If i take all the systems of chains of events ...
3answers
355 views

### How do we know that certain quantum effects are random?

I was looking at a website that claims to generate random numbers from observation of quantum effects. This lead me to question how we know that the numbers are truly random. When we observe a ...
5answers
5k views

### Do identical starting conditions always lead to identical outcomes?

My friend and I are discussing whether or not physical phenomena are deterministic. Let's say, for example, that we have a 3-dimensional box with balls inside of it upon which no gravitational forces ...
2answers
440 views

### Randomness in Quantum Mechanics

Is the quantum world really random?How can one be sure that there are no variables that can actually predict the outcome like they do in Newtonian physics?
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### The principle of Quantum indetermination

Well, it is a amazing fact that Quantum world deals with indeterminism, one can't tell about the system without directly "seeing" it. (Many novels, short stories are also formed on the same) My ...
1answer
83 views

### Is a lightening strike deterministic?

This relates to a previous question: Is a dice roll deterministic? Essentially, I'm trying to get a better understanding of how quantum indeterminacy interacts with the macro world. It seems to me ...
3answers
931 views

### Is quantum mechanics truly probabilistic?

Probability arises inherently from a lack of information. For example, if I were to take a ball out of a bag with 3 yellow and 2 white balls, I would have a 0.6 probability of getting a yellow and a 0....
1answer
163 views

### Classical indeterminacy and measurement uncertainty

In one of his lectures, Feynman argues that classical physics is essentially indeterminate. Here I have tried to distill his original argument which was related to collisions of (classical) atoms in ...
1answer
163 views

### Is there a consensus about the trueness of the randomness in QM? [duplicate]

I personally believe that there is a very strong case in favor of true randomness in QM but not being a physicist I would like to know from experts if there is a consensus about this. @John Rennie: ...