Add this Tag for questions on information theory applied to physics, especially in the fields of statistical mechanics and thermodynamics, the black hole information paradox, complexity of dynamical and physical systems and questions to do with whether information is conserved by physical systems. ...

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4
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2answers
113 views

What is the black hole information paradox really? [on hold]

Preliminaries What is the black hole information paradox really? Is it a sophisticated way to ponder and debate the existence of an operator on the boundary that can tease out the interior of a ...
3
votes
3answers
226 views

Is Bekenstein entropy limit inconsistent with universal continuity?

It is unknown whether the universe is discrete or continuous in its intricate quantum level structure. See for example: Can universal continuity be experimentally falsified? Is the universe finite ...
1
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0answers
37 views

Is it possible in this Universe to communicate a bit of information with energy that scales sub-linearly with distance?

If we look at all the ways that people do communicate information, they all seem to have a cost "at least linear in distance." For example, communicating over a wire has attenutation, so the energy ...
5
votes
2answers
57 views

Books on entropy [on hold]

What books introduce entropy in a intuitive, elementary way (at most, for a person with undergraduate physics studies)? The book should not necessarily introduce entropy in relation only to ...
-1
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0answers
103 views

Did the laws of physics originate due to evolution like in biology? [closed]

Can someone protect this question or edit it so that it does not get closed, it is important to me. Danke. The next two paragraphs are preliminaries you can skip if you'd like. So listen, I have some ...
8
votes
4answers
370 views

Is information entropy the same as thermodynamic entropy?

Context In one of his most popular books Guards! Guards!, Terry Pratchett makes an entropy joke: Knowledge equals Power, which equals Energy, which equals Mass Pratchett is a fantasy comedian ...
1
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3answers
101 views

Information, entanglement and EPR

I'm currently trying to understand why superluminal information transport is not possible. Therefore, I would like to get some help concerning the definition of information or the general setting. ...
1
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1answer
63 views

Does conservation of information mean that the direction of causality is arbitrary? [duplicate]

If it is the case that the information content of the universe is conserved, and the past can be constructed from a complete knowledge of the future just as easily as vice versa, then is there any ...
3
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0answers
33 views

Implication of non-positive tripartite information

Hayden et al 2011 showed that tripartite information is non-positive given Ryu-Takanayagi formula. (For definition of tripartite information, see for instance section 4.4 of this paper) Is there ...
4
votes
3answers
310 views

Speed of Dark experiment, does it *really* travel faster than light? [duplicate]

I have seen many folks doing this Moon shadow experiment concluding that shadow from point A on the Moon can travel to point B on the Moon faster than light. What I fail to understand here (and I am ...
0
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0answers
33 views

Is it feasible to store large amounts of information on DNA molecules (for years)?

This initially might seem like a biology based question, but I want to concentrate on the physics of DNA molecules, used purely as a manmade stable substrate for storing information. A 2013 Ted Talk ...
2
votes
1answer
34 views

Is Entropy Maximized, or Just Increased?

Do different real processes involve different rates of change of entropy? (Is the rate of change of entropy constant with time throughout all regions of space, or perhaps in other words, constant with ...
4
votes
4answers
652 views

Entropy and Information

Several posts and my classes in thermodynamics equate increase in entropy with loss of information. Shannon clearly showed that the information content of a message is zero when its entropy is zero ...
0
votes
1answer
74 views

What gives a particle its identity?

A lot of very smart people have stitched together the standard model, and I accept it. I don't understand it, but I assume there should be a mechanism of sorts that gives a particle some fundamental ...
1
vote
1answer
38 views

What processes create or destroy information?

From a classical standpoint, it seems pretty clear that information can be easily lost. If you knock over a bookshelf and the books fall out, it seems like their initial order on the shelf cannot be ...
-1
votes
1answer
40 views

Is there a way to prove information entropy?

Information entropy is a very general term involving everything from the tendency of material to decay (in all the 3 meanings) to the fact that you need energy to sort your books alphabetically. Let'...
5
votes
1answer
71 views

Holevo Information and Quantum Mutual Information

This question is about the difference between Quantum Mutual Information and Holevo Information of quantum channels. From http://arxiv.org/pdf/1004.2495.pdf equation 7 we know that the sum of quantum ...
-2
votes
2answers
67 views

Can a non-entangled qubit be teleported by entangling it?

Let's say I have a qubit that is not entangled in state $\psi$. I want to teleport this qubit by entangling it with another qubit but still getting $\psi$ back in the end. Is this possible, or would ...
1
vote
3answers
330 views

Speed of heat / quantification of heat and other magnitudes

Is the speed of heat infinite? When solving the heat equation in a semi-infinite bar, we can see that a pulse in the finite end draws an immediate change in every point of the bar. So, at any given ...
3
votes
1answer
39 views

About the holographic principle

I read at a book this quote "As the degrees of freedom of a particle are the product of all the degrees of freedom of its sub-particles, were a particle to have infinite subdivisions into lower-...
0
votes
1answer
85 views

Can a system be PERFECTLY simulated by a quantum (and classical) computer? [closed]

This is a thought experiment, and as such will assume some crazy things. Let's say I decide to perfectly simulate my university as it is right now. I use a magic machine to instantly scan the entire ...
39
votes
4answers
17k views

Maximum theoretical data density

Our ability to store data on or in physical media continues to grow, with the maximum amount a data you can store in a given volume increasing exponentially from year to year. Storage devices continue ...
13
votes
2answers
339 views

Did merging Black Holes in GW150914 give up entropy and information to the gravitational waves, since they lost 3 solar masses?

Since the final Black Hole (BH) had 3 solar masses less of mass than the original binary BH, it seems the 2 BHs lost mass, and with it event surface area, entropy, and information. If that came from ...
20
votes
2answers
2k views

What do physicists mean by “information”?

On the question why certain velocities (i.e. phase velocity) can be greater than the speed of light, people will say something like: since no matter or "information" is transferred, therefore the ...
1
vote
1answer
45 views

Shannon entropy and information function

I'm trying to solve a exercise about Shannon entropy. I've tried some things but I can't solve it, and couldn't find information on the internet. Let's see. We have the Shannon entropy, and a system ...
0
votes
0answers
48 views

Deriving an upper limit to the information in a human brain

For this question I am presuming that the human brain works deterministically and all information in a human brain is, once you get down to the lowest level, stored through the arrangement and other ...
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0answers
25 views

What are some good books on foundations of Thermodynamics [duplicate]

I am not looking for some introductory texts, graduate text, etc. I am looking for something that addresses to foundational problems in thermodynamics and statistical mechanics.
4
votes
2answers
185 views

Maxwell demon with memory storage

Let's consider a classical Maxwell demon as described in wiki https://en.wikipedia.org/wiki/Maxwell%27s_demon. It spends energy for measuring velocities and coordinates of some particles and uses the ...
0
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0answers
42 views

How many atoms do we need to store a bit?

And which kind of storage (HDD, flash, blue-ray, etc) has the most efficient atoms/bit ratio?
3
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0answers
64 views

Can Observation change entropy?

I don't know whether this even makes any sense, but if 'observation' can be considered as 'recieving and reading information', can an act of observation (of a system) change (increase or decrease) its ...
27
votes
3answers
2k views

How to recover an unfocussed image

If the lenses in a camera are not set correctly, the intended subject will be "out of focus" in the resulting image. There seems to be no loss of information here. The photons are just steered to the ...
1
vote
1answer
46 views

Reference for statistical mechanics from information theoretic view

I am interested in knowing if some one here knows book/notes for statistical mechanics from the information theoretic viewpoint.
0
votes
1answer
42 views

Is total order and total chaos equal?

Imagine an ideal gas which possesses maximum entropy. It´s not difficult to describe the state of the system because once you know some part of the system you can say how the whole system looks like. ...
0
votes
0answers
47 views

Can a massive imploding sphere smash the holographic principle and conservation of information into oblivion?

Let $\text{BH}_1$ be a black hole of mass $M_1$, zero charge and angular momentum, and event horizon radius $R_1=\frac{2GM_1}{c^2}$. Alice is loitering at distance (all distances here are from the ...
0
votes
2answers
93 views

Does quantum entangled particle release energy when its “twin” is measured? [closed]

So I was just thinking a bit, and I came up with a couple of questions. As we all know the scenario: We have two quantum entangled particles. Let's call them A and B. We like to measure the state of ...
3
votes
1answer
148 views

Understanding the quantum eraser from a quantum information stand point

Is there a way to understand the quantum eraser experiment in terms of quantum information? In particular, is there a quantum circuit that would function as a quantum eraser experiment? The issue I'm ...
1
vote
1answer
116 views

Understanding the delayed choice quantum eraser from a quantum information stand point

A continuation of Understanding the quantum eraser from a quantum information stand point What quantum circuit would correspond to delayed choice? In particular, the decision of whether to not to ...
2
votes
1answer
54 views

Quantification of uncertainty, or information loss, when modeling a physical system?

Say I have a physical circuit (say a battery, wires and an incandescent lamp) that I want to model. To model it I could perhaps use: traditional circuit theory some kind of finite element analysis ...
0
votes
1answer
75 views

Why doesn't the quantum eraser violate the no-deletion theorem?

In the quantum eraser experiment and its variants, you basically have a double slit experiment, where you detect which slit the photon went through, but then forget this information. My question is, ...
0
votes
1answer
109 views

Is it impossible to practically predict the future?

For the sake of curiosity, let us postulate a universe that can be completely described by mathematics. Let us further postulate, that humankind has fully discovered all the fundamental laws of nature....
0
votes
1answer
40 views

Is the information that a human brain (and body) “contains” superflorous to the information contained within the atoms of the body?

Layman here. I recently watched this video talking about Stephen Hawking's theory of hairy black holes. The speaker mentions, as I've heard before, that once "something" has entered a blackhole its ...
9
votes
2answers
331 views

Information Preservation and Burning Books

I recently read an article in the NY Times called A Black Hole Mystery Wrapped in a Firewall Paradox. I really liked the article, but reading one quote immediately made me think of asking Physics.SE a ...
2
votes
1answer
220 views

Reference paper to support information — energy relation $\left(kT \ln2 \rm\frac{J}{bit}\right)\;.$

In answer to Maxwell's Demon Constant (Information-Energy equivalence) there is stated that one bit of information allows to perform $kT \cdot \ln2$ Joules of work. Which paper supports the thesis?...
6
votes
3answers
601 views

Confusion regarding entropy, reference papers request

1.a In paragraph at Wikipedia/Entropy it is stated: This is because energy supplied at a high temperature (i.e. with low entropy) tends to be more useful than the same amount of energy ...
1
vote
2answers
1k views

can we transfer data via quantum entanglement (likewise we communicate today) to a specific target

Today we rely on electromagnetic field for communication. I'm a entrepreneur, I want to know why we can't transfer data with this technology to transfer data from one place to another place. It can ...
0
votes
0answers
43 views

Thermodynamic reversibility, Landauer's principle, and Maxwell's demon

A lot of the literature surrounding Landauer's principle (and relating it to Maxwell's demon) talks about whether or not a logically irreversible process can be thermodynamically reversible. But why ...
3
votes
1answer
95 views

Infinite bits to describe a qubit

In the Quantum Computation book by Nielsen and Chuang, the authors write in the context of quantum teleportation "Even if she (Alice) did know the state |w> , describing it precisely takes an ...
3
votes
3answers
253 views

The role of context in information theory

Consider Hofstaedter’s jukebox analogy: A jukebox that contains only one record, but many different record players, each of which interprets that one record in a different way to produce an entirely ...
3
votes
4answers
207 views

Is it possible to learn about an event that occurred outside of your observable universe?

I have mixed intuitions about this. On one hand, nothing can travel faster than the speed of light and if there is enough space between you and an event then a signal will get stuck in the middle of ...
6
votes
4answers
411 views

If nothing ever falls into a black hole, why is there a puzzle about information?

From an outside perspective, nothing can ever pass the event horizon. It just scooches asymptotically close to the event horizon. So (from our perspective on earth), when a black hole reduces in mass,...