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6
votes
2answers
435 views

Why is classical mechanics determinism based on position and momentum only and not forces and scattering rules?

Consider a closed system (say a box) of $n$ particles. There is a well-known idiom/meme/law in classical mechanics that says that the position and momentum of those $n$ particles is all that is needed ...
4
votes
0answers
103 views

Free Will Theorem question

The Kochen-Specker Theorem says, if I understand it correctly, that the results of spin measurements cannot be predetermined independent of measurement. They get to this conclusion by describing 33 ...
5
votes
1answer
258 views

Why must allowable physical laws have reversibility?

I'm watching Susskind's video lectures and he says in the first lecture on classical mechanics that for a physical law to be allowable in classical mechanics it must be reversible, in the sense that ...
0
votes
1answer
95 views

Are all natural processes that are bigger than a molecule also deterministic? [closed]

Is there something bigger than a molecule and still random in nature? I know that the decay of an unstable atom cannot be predicted, only the probability of decay can be calculated. Molecules moving ...
2
votes
3answers
125 views

What are the borders of determinism?

I, a newbie in physics, often read about "near determinism", which is most probably the actual state of physics, meaning: the "big world" is deterministic, but very small things (atoms and smaller) ...
4
votes
3answers
268 views

Does the uncertainty principle make simulation of systems impossible?

Is it possible to fully define a system, then be incapable of simulating or calculating its future states due to the Uncertainty Principle? If it can be done, how?
3
votes
1answer
230 views

How would one test the hypothesis of human free will? [closed]

In this context, I define free will to mean that a human's high-level actions (not the quantum states of his particles) are not determined, in the same sense that some quantum effects are not ...
0
votes
0answers
33 views

Is the universe immediately dependent upon the past? [duplicate]

Given complete knowledge of the precise state of every property of every particle and energy phenomenon existing in our universe for a given infinitely small frame of time, is it possible to ...
2
votes
2answers
220 views

Is inflation deterministic?

In some theories inflation is supposed to be able to turn quantum fluctuations into macroscopic inhomogeneities. I don't understand how an isolated system such as the universe can undergo such a ...
2
votes
2answers
1k views

Are random quantum phenomena happening without a cause?

In everyday life, most of us assumes every event and object has a cause in some sense. I am wondering if the same is true for quantum physics. Does the random nature of quantum phenomena mean they ...
1
vote
1answer
239 views

Why is this classical system seemingly non-deterministic?

So, I was solving this problem1 and I realized that the system given seems to be non-deterministic when analysed with classical laws. The situation is thus: A rope is wrapped for an angle of ...
8
votes
2answers
557 views

Why were the fathers of quantum mechanics so sure radioactive decay was indeterministic?

The classic example of an indeterministic system is a radioactive isotope, e.g. the one that kills Schrödinger's cat. I get there are arguments against hidden variables in quantum mechanics, but how ...
1
vote
2answers
386 views

What are the *necessary* conditions to deterministic chaos?

What are the necessary conditions (not saying sufficient conditions) in mathematical terms that a deterministic dynamic system can transit to deterministic chaos? We collected yet: A positive ...
3
votes
2answers
776 views

What are the principles of deterministic chaos?

I see in literature very different (and chaotic) descriptions of what is deterministic chaos. Can you explain to me based in a type of formal definition, which principles need to be exactly fulfilled ...
2
votes
2answers
278 views

Is everything pre-decided? [closed]

"There is nowhere in the universe where the laws of physics are violated." Considering this general to be true,can i conclude that everything is pre-decided? I can explain this in the following ...
2
votes
3answers
244 views

Can deterministic world view be denied by anything other than quantum mechanics

If we ignored quantum mechanics and looked at the world with a deterministic Newtonian view. Does not that mean that there is no randomness and that if all the information of the state of the universe ...
2
votes
1answer
352 views

Is Brownian motion a deterministic system?

Is Brownian motion a deterministic system? I.e the motion of all particles are completely determined or is there an innate indeterminism like quantum systems?
55
votes
5answers
24k views

Is the universe fundamentally deterministic?

I'm not sure if this is the right place to ask this question. I realise that this maybe a borderline philosophical question at this point in time, therefore feel free to close this question if you ...
8
votes
7answers
740 views

Why Quantum Mechanics as a non-fundamental effective theory?

My question: What (physical or mathematical) reasons (not philosophical) do some physicists ('t Hooft, Penrose, Smolin,...) argue/have in order to think that Quantum Mechanics could be substituted by ...
8
votes
3answers
1k views

Determinism, classical probabilities, and/or quantum mechanics?

[I]f you want a universe with certain very generic properties, you seem forced to one of three choices: (1) determinism, (2) classical probabilities, or (3) quantum mechanics. [My emphasis.] ...
3
votes
6answers
392 views

How do we know that there isn't a classical solution to the measurement problem/Quantum Mechanical uncertainty?

It was mentioned to me that it can be shown that there is no classical explanation for the uncertainty in Quantum Mechanics -- i.e. that there are no hidden workings that we have just not yet seen, ...
6
votes
2answers
252 views

Bell's Theorem graph

My friends and I got into an argument about determinism, and I brought up that quantum events are random. But I couldn't prove it. I found the Wikipedia page on Bell's theorem, which seems to imply ...
16
votes
5answers
414 views

Does the mass point move?

There is a question regarding basic physical understanding. Assume you have a mass point (or just a ball if you like) that is constrained on a line. You know that at $t=0$ its position is $0$, i.e., ...
4
votes
4answers
379 views

Are photons deterministic?

I propose the following scenario: At $t=0$, a photon is emitted from a star. At $t=n$, said photon is received and interpreted by some detector. My question is whether or not it is accurate to say ...
-3
votes
2answers
178 views

Argument against computer consciousness [closed]

Imagine that we have a computer program that produces the conscious awareness of the present moment. Let us assume that every time the program is run a counter is incremented. Let us also assume ...
16
votes
3answers
943 views

Does quantum computing rely on particular interpretations of quantum mechanics?

It is my understanding that quantum computing relies on quantum superposition and entanglement to work--qbits must exist in all states simultaneously before giving a particular result when observed. ...
1
vote
2answers
1k views

Is the movement of electrons truly random?

The result of rolling dice is considered pseudo-random because it depends on an almost endless list of factors (how you roll it, the terrain it lands on, etc.), but it is not TRULY random. Is the ...
1
vote
1answer
132 views

reversible cellular automata

Let's suppose a cellular automaton has a value $b(r,t)$ belongs to $Q$ at site $r$ and time $t$, where $Q$ is the set of possible states at each site. Let $N(r, t)$ be the values of the states of all ...
1
vote
2answers
409 views

What are hidden variables exactly?

What are hidden variables in quantum mechanics? I am aware there are many types but what exactly do they mean or even "do" exactly? Do they mean that the quantum indeterminacy becomes hidden but ...
4
votes
3answers
452 views

Are quantum mechanics and determinism actually irreconcilable? [closed]

As a preface, I am not a physicist. I'm simply interested in abstract physics and fundamental principles of the universe and such. As such, if you can provide an answer for the layman (as ...
4
votes
2answers
225 views

Can we write down a dynamical law of physics which is totally non-deterministic?

In classical mechanics, $F=ma$ tells us how to evolve a system at time $t=t_0$ to $t=t_0+dt$. In quantum mechanics, the Schrodinger equation gives us a similar recipe. These equations are, in a ...
12
votes
4answers
3k views

Does the future already exist? If so, which one?

In the NOVA Fabric of the Cosmos program, Brian Greene explains a theory in which there is no "now", or more specifically, now is relative. He describes an alien riding a bicycle on a far off planet ...
2
votes
2answers
600 views

Is 't Hooft's Determinism based on the holographic principle?

Does 't Hooft's determinism work need the holographic principle in order to work or is it just an extension of his work?
-2
votes
1answer
500 views

Quantum superposition and fate [closed]

First of all, sorry for my knowledge of physics. Maybe my question is too obvious but I want to ask it. I am thinking about fate and if it exist or no. According to my assumption if I take any ...
8
votes
3answers
1k views

How does Bell's theorem rule out the possibility of local hidden variables?

It seems to be common consensus that the world is non-deterministic and this is proved by Bell's theorem. But even though Bell's experiments proved that the theory of quantum mechanics work, How does ...
11
votes
1answer
572 views

What are the 't Hooft papers about classical models underlying QM?

Gerard 't Hooft states on his webpage: I have mathematically sound equations that show how classical models generate quantum mechanics. Also, there are some interesting discussions here on ...
2
votes
1answer
140 views

Basic question about probability and measurements

Say I have a Galton box, i.e. a ball dropping on a row of solid bodies. Now I want to calculate the probability distribution of the movement of the ball based on the properties of the body (case A). ...
4
votes
3answers
3k views

How would we perceive time going backwards? [closed]

I haven't taken Physics in University. Lately, I've been reading about some of the branches of physics through Wikipedia. I read several times that many of the theoretical models do not explain why ...
3
votes
1answer
206 views

In QM, does random data “come from anywhere”? Also, what are the properties of the data?

I have only taken a basic quantum mechanics course (this book, so you know where I'm coming from), but I've been wondering about something. If we set up a quantum system in a known state and take a ...
5
votes
4answers
371 views

Are a quantum mechanical system a chaotic (yet deterministic) system?

The title is slightly misleading. I really want to know if the randomness and probabilities observed in quantum mechanics is really just the result of a chaotic (yet deterministic) system. If it is ...
2
votes
3answers
131 views

Reference for the predictability of rigid body dynamics

I'm looking for a reference, journal article, paper, etc. that supports the idea that classical mechanics, in particular rigid body dynamics, is largely predictable. A view coming from the background ...
20
votes
2answers
2k views

Norton's dome and its equation

Norton's dome is the curve $$h(r) = -\frac{2}{3g} r ^{3/2}.$$ Where $h$ is the height and $r$ is radial arc distance along the dome. The top of the dome is at $h = 0$. Via Norton's web. If we put ...
4
votes
0answers
498 views

Is there any simple quantum model by Gerard 't Hooft which can explain the double slit experiment?

This question is directed to Prof. 't Hooft and anybody who is familiar with his papers. It is a reaction to Prof. 't Hooft's question why nobody is excited about his classical models for quantum ...
5
votes
0answers
139 views

Is it possible to reproduce the energy spectrum of quantum chaos using classical cellular automata?

Is it possible to reproduce the energy spectrum of quantum chaos using classical cellular automata? It's hardly impressive to reproduce harmonic oscillators.
77
votes
7answers
10k views

Why do people categorically dismiss some simple quantum models?

Deterministic models. Clarification of the question: The problem with these blogs is that people are inclined to start yelling at each other. (I admit, I got infected and it's difficult not to raise ...
21
votes
1answer
2k views

In 't Hooft beable models, do measurements keep states classical?

This is a questions on 't Hooft's beable models (see here: Discreteness and Determinism in Superstrings?) for quantum mechanics, and the goal is to understand to what extent these succeed in ...
3
votes
3answers
1k views

Can superdeterminism resolve contextuality, entanglement and Shor's algorithm in quantum mechanics?

Superdeterminism is the idea that the apparent freedom for the choice of experimental apparatuses and their settings are nothing but an illusion. Contextuality is the dependence of the properties of a ...
6
votes
1answer
427 views

Cellular automata rules for quantum mechanics

My limited understanding of quantum theory is that a quantum system is completely described by its wave function, which deterministically evolves according to Schrödinger's equation until wave ...
5
votes
3answers
1k views

What is happening over the 15 minutes it takes a neutron to decay?

I've read that free neutrons decay into a proton, electron and neutrino with an average lifespan of about 15 minutes. Is there anything physically different about a neutron that has existed for 14 ...
1
vote
1answer
197 views

Question regarding the Bohm interpretation [closed]

I tried to understand the Bohm interpretation and this is what picture appeared to me. Please tell me if I understood something incorrectly. All particles have definite positions and follow ...