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7
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7answers
630 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 ...
7
votes
3answers
766 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.] ...
2
votes
5answers
317 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
219 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
372 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
369 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
151 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 ...
14
votes
3answers
770 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
882 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
115 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
280 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 ...
3
votes
3answers
390 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
195 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
2k 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
524 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?
-3
votes
1answer
420 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
517 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
128 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
2k 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
202 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 ...
4
votes
4answers
321 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
120 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 ...
17
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
446 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
122 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.
62
votes
7answers
8k 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 ...
20
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
316 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
687 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 ...
9
votes
4answers
794 views

Can quantum mechanics really be the same as underlying deterministic theory?

I am perplexed by recent papers by 't Hooft giving an explicit construction for an underlying deterministic theory based on integers that is indistinguishable from quantum mechanics at experimentally ...
25
votes
11answers
6k views

Discreteness and Determinism in Superstrings?

So Gerard 't Hooft has a brand new paper (thanks to Mitchell Porter for making me aware of it) so this is somewhat of a expansion to the question I posed on this site a month or so ago regarding 't ...
18
votes
5answers
4k views

Why do people rule out local hidden variables?

I bet the automatic response to my question would be "Bell's theorem" and of course I am not disputing Bell's proof. I am however uncertain of one of his assumptions. The so called "no conspiracy" ...
6
votes
3answers
2k views

Can randomness exist?

Considering every cause has an action, how can anything be random? For something to happen, it must have a cause and through that definition it can't be random. Considering this why are many quantum ...
2
votes
2answers
1k views

If randomness doesn't exist, how come the universe isn't a perfect sphere with predictable distribution of matter?

I'm presuming that the scientific community pretty much agrees that randomness doesn't exits, and that everything has a cause. Please correct me if I'm wrong, I've heard of quantum mechanics, but as ...
3
votes
3answers
366 views

Power laws and deterministic systems

I am facing the following question. It is well known that power laws arise in many situations in nature. They arise even in thats physical systems that are completely deterministic (e.g. sand piles). ...
4
votes
1answer
177 views

Event-by-Event Simulation of Quantum Phenomena

I just recently stumbled over http://rugth30.phys.rug.nl/dlm/ and http://www.sbfisica.org.br/bjp/files/v38_26.pdf As the title suggests these are presentations of mathematical models capable of ...
7
votes
4answers
886 views

Does the “Andromeda Paradox” (Rietdijk–Putnam-Penrose) imply a completely deterministic universe?

Wikipedia article: http://en.wikipedia.org/wiki/Rietdijk–Putnam_argument Abstract of 1966 Rietdijk paper: A proof is given that there does not exist an event, that is not already in the past for ...
3
votes
2answers
813 views

Can cellular automata be reconcilied with quantum mechanics?

CAs are deterministic representations of the universe, which, according to the Bell's inequality are not entirely accurate. Cells interact "locally" (only with the closest neighbours), while quantum ...
3
votes
4answers
634 views

How can indeterminacy in quantum mechanics be derived from lack of ability to observe a cause?

I don't get this part of quantum mechanics. I get the part that you can't observe particles and not affect their behavior because you are shooting photons to them while you are observing them, but ...
3
votes
2answers
280 views

Why doesn't phase space contain acceleration/forces?

I'm watching some Physics lectures on the internet by Leonard Susskind: http://www.youtube.com/watch?v=pyX8kQ-JzHI&feature=BFa&list=PL189C0DCE90CB6D81&lf=plpp_video In this lecture, and ...
10
votes
5answers
2k views

Deterministic quantum mechanics

I came across a very recent paper by Gerard 't Hooft The abstract says: It is often claimed that the collapse of the wave function and Born's rule to interpret the square of the norm as a ...
14
votes
5answers
1k views

What combinations of realism, non-locality, and contextuality are ruled out in quantum theory?

Bell's inequality theorem, along with experimental evidence, shows that we cannot have both realism and locality. While I don't fully understand it, Leggett's inequality takes this a step further and ...
9
votes
4answers
995 views

By what mechanism do quantum effects become observable in normal life at the macroscopic level?

By what mechanism do quantum effects become observable in normal life at the macroscopic level? For instance, when two molecules "collide" is the momentum a probabilistic event wherein the end state ...
-2
votes
2answers
416 views

Chaos and quantum physics: How many ways can a bonfire burn?

I'm interested in the extent to which quantum physical effects are seen at a macroscopic level. I might get some of the physics wrong, but I think I'll get it close enough that I can ask the ...
10
votes
6answers
2k views

Chaos theory and determinism

My professor in class went a little over chaos theory, and basically said that Newtonian determinism no longer applies, since as time goes to infinity, no matter how close together two initial points ...
27
votes
5answers
3k views

Is Stephen Wolfram's NKS, an attempt to explain the universe with cellular automata, in conflict with Bell's Theorem?

Stephen Wolfram's A New Kind of Science (NKS) hit the bookstores in 2002 with maximum hype. His thesis is that the laws of physics can be generated by various cellular automata--simple programs ...
12
votes
4answers
1k views

Is randomness deterministic?

Is randomness based on lack of knowledge or behavior of universe is true random? Or in other words, are the allegation by EPR about hidden variable in the QM theory justifiable? What evidence can ...
19
votes
10answers
1k views

Why can't the outcome of a QM measurement be calculated a-priori?

Quantum Mechanics is very successful in determining the overall statistical distribution of many measurements of the same process. On the other hand, it is completely clueless in determining the ...