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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9
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3answers
2k views

How are physics and computer science getting united? [on hold]

How is theoretical computer science getting united with physics? Phenomena like Quantum Computing uses Quantum Mechanics to be able to compute things, how are computers helping not just to model our ...
0
votes
0answers
46 views

Arrow of Time in Information transfer

I am writing a sci-fi script and need some legitimate theory to back up a central story element (so there's no real world application): Could there be a logically consistent theory supporting the ...
3
votes
3answers
382 views

Has anyone ever tried to formulate physics based on computer science or information processing?

Some physicists and university researchers say it's possible to test the theory that our entire universe exists inside a computer simulation, like in the 1999 film "The Matrix." In 2003, University ...
1
vote
1answer
98 views

Quantum violation of Newton's Third Law? [closed]

From this site: http://www.learning-mind.com/5-thought-provoking-quantum-experiments-showing-that-reality-is-an-illusion/ I gained the knowledge that a group of scientists, upon measuring a tiny ...
2
votes
1answer
75 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 ...
1
vote
2answers
54 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 ...
4
votes
3answers
196 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 ...
2
votes
1answer
127 views

Are only 2 bits of information transmitted in quantum teleportation?

Prompted by the recent success in Delft, I've been reading a number of papers and articles about quantum teleportation. I'm comfortable with my understanding of most aspects but haven't found much ...
10
votes
1answer
460 views

How does Landauer's Principle apply in quantum (and generally reversible) computing

I understand that a reversible computer does not dissipate heat through the Landauer's principle whilst running - the memory state at all times is a bijective function of the state at any other time. ...
2
votes
1answer
36 views

Is it possible to calculate the information content of matter? How?

I know the Bekestein bound is the upper bound for the information content of a region of space, but is it possible to actually calculate that information content (number of bits, not the bits ...
1
vote
0answers
43 views

Black Hole Entropy Calculation

I was watching "Leonard Susskind on The World As Hologram" ( youtube ). At one point he describes the way Bekenstein calculates the entropy of a black hole. Paraphrasing: Take a minimally sized black ...
0
votes
2answers
64 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 ...
1
vote
0answers
28 views

Is not the idea of a continuous universe and finite information density mutually exclusive?

As far as I understand, the universe is not divided into discrete units, but rather its continuous. This seems backed up by a quick search: Does the Planck scale imply that spacetime is discrete? ...
4
votes
2answers
34 views

On unfocused images, their information content and possible restoration

So, when an image is out of focus the light of any given point of the object does not refocus exactly at one point on the screen, but is spread out around a region, such that the light of the image at ...
1
vote
1answer
69 views

Information in twisted light

New Scientist has a story on the use of twisted light to store multiple bits of information per photon. What is this technology, and what are the information density limits per photon? "MOZART and ...
4
votes
2answers
1k views

Where does information go if thermodynamic death?

Often read that until Hawking the black holes were introducing a problem with information. Allegedly information should be unable disappear, while this was happening in classic black holes. What ...
0
votes
2answers
124 views

How can Maxwell's Demon erase information while a black hole can not?

It is stated, that information can't disappear even in black holes. On the other hand, it is stated, that mystic beings, like Maxwell demons, can easily erase any information if they just pay with ...
-4
votes
1answer
76 views

Is information a form of energy? [closed]

To better describe my question, do the following experiment: Calculate x=12+26+67+71 Now you might have spent some time in getting the answer. You burnt sugar, you used up energy to get the ...
4
votes
1answer
69 views

What is the interpretatation of individual contributions to the Shannon entropy?

If $X=\{ x_1,x_2,\dots,x_n\}$ are assigned probabilities $p(x_i)$, then the entropy is defined as $\sum_{i=1}^n\ p(x_i)\,\cdot\left(-\log p(x_i)\right).$ One may call $I(x_i)=-\log p(x_i)$ the ...
19
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 ...
4
votes
1answer
224 views

No hair theorem and black hole entropy

The no hair theorem says that black holes rapidly converge to a state that is completely described just by their mass, spin and charge. Black hole thermodynamics says that the black hole entropy is ...
2
votes
3answers
846 views

Sending information faster than light

If I could ever send my friend any information faster than light it would violate causality. If he just guesses the information and acts on it before he could ever recieve it, everything is fine. What ...
9
votes
3answers
2k views

How many bytes can the observable universe store?

Is the number of states in the Universe countable? What framework could be used to answer the question in the title?
35
votes
6answers
5k views

Is there a thermodynamic limit on how efficiently you can solve a Rubik's cube?

Suppose I build a machine which will be given Rubik's cubes that have been scrambled to one of the $\sim 2^{65}$ possible positions of the cube, chosen uniformly at random. Is it possible for the ...
0
votes
1answer
38 views

Total information in the universe

I have no business in this forum. It seems to me the total amount of information in the universe is finite determined by pre-big bang conditins. Information is neither created or destroyed only ...
0
votes
0answers
58 views

Upper limit on the size of the “unobservable” universe based on surface area divided by Planck constant?

There are many kinds of size scale to the universe one can talk of. Much has been discussed with the concept of the upper limit of "bits" contained in the observable universe and therefore the total ...
8
votes
2answers
137 views

Could you theoretically map the internal distribution of mass in a black hole using Hawking radiation?

Assuming you could measure the qualities of the radiation emanating from all around a black hole, could this be used to determine the internal geometry or makeup of the mass inside?
18
votes
5answers
4k views

Why does the speed of light totally prevent instantaneous information exchange?

Based on the classical light-cone approach it's easy to see you can't transmit information faster than $c$ but why does the speed of light (as far as I know) treat information transmission in this way ...
0
votes
0answers
57 views

How does the universe store information

I have read that entropy is responsible for the storage of information in the universe; that information increases with entropy increase. and that information is never lost. Is this correct? But ...
6
votes
3answers
874 views

Is there really time reversibility in physics?

First, how i got to the question. I was randomly looking at this page: http://en.wikipedia.org/wiki/Langton%27s_ant describing some sort of cellular automaton. Here is the path of this automaton ...
1
vote
0answers
41 views

Why is information transfer usually done through frequency modulation but not amplitude modulation [closed]

For example, if we were to transmit a sequence of code, we could do so by alternating the flash rate of the source, or alternate the strength of the source. Both methods can represent a large amount ...
2
votes
2answers
92 views

Superimposed state vs. zero amplitude state

Two equal amplitude wave pulses approaching each other through some medium such as a string may form a region of zero amplitude when they overlap completely. At this point, the location of overlap is ...
6
votes
4answers
2k views

Exorcism of Maxwell's Demon

I am possessed! Yes, with the thinking that if there is actually a Maxwell's Demon, then it would open the negligible weighted door which would ultimately make the second law invalid. But really can ...
5
votes
2answers
122 views

Bekenstein bound for electron?

Using the Wikipedia version of the Bekenstein bound, and substituting the Wikipedia values for electron mass and radius, one obtains 0.0662 bits. Does this really mean that a system, any system, ...
0
votes
2answers
30 views

entropy-infomartion correlation at preliminary universe?

according to the theory of cosmic inflation after Alan Guth, the information should have travelled 100 times the speed of light at the very beginning after the big bang. -when we talk about ...
1
vote
2answers
76 views

Does information paradox in the Many Worlds interpretation cause a problem? [closed]

I'm taking a philosophy of time travel class. In one of the lectures, the teacher was discussing problems with the Many Worlds interpretation. He talked about how since anything that can possibly ...
0
votes
0answers
40 views

No Hair systems and black hole entropy

To my understanding, a black hole is a no hair system. So it can be described just by its mass, spin and charge. In other words it does not differentiate where its mass comes from, so it could be made ...
6
votes
4answers
766 views

Uncertainty Principle for Information?

I'm not familiar (yet) on how Information theory can be emerged/used in QM/QFT but I was thinking about this question: While we have Heisenberg uncertainty principle on measuring coupled observables, ...
1
vote
0answers
94 views

What exactly is black hole complementarity and why is it necessary for solving black hole information paradox?

What exactly is black hole complementarity and why is it necessary for solving black hole information paradox? The first question is about the story of vacuum fluctuation causing Hawking radiations. ...
6
votes
2answers
141 views

How can the microstates be measured with zero energy expenditure?

James P. Sethna. Statistical Mechanics. Exercise 5.2: What prevents a Maxwellian demon from using an atom in an unknown state to extract work? The demon must first measure which side of the ...
1
vote
2answers
58 views

How do we represent 'smell' and 'taste' as signals?

I was wondering if we could represent 'smell' and 'taste' as signals like we do for audio. How do we mathematically represent them? Is there any research papers related to it? Can someone give me ...
31
votes
5answers
3k views

What is the most efficient information storage?

What is the most efficient way to store data that is currently hypothesized? Is it theoretically possible to store more than one bit per atom? Until Floris' comment, I hadn't considered that ...
21
votes
5answers
2k views

Where does deleted information go?

I've heard that, in classical and quantum mechanics, the law of conservation of information holds. I always wonder where my deleted files and folders have gone on my computer. It must be somewhere I ...
3
votes
1answer
60 views

Is there a lower bound on energy needed to transfer one bit of information?

Let's say we want to transmit information between to stations (points in space). Is there a minimal energy required to transfer a single bit of information, assuming that we tolerate that the bit ...
1
vote
1answer
23 views

Can data be transmitted from one object to another one during electrostatic discharge (ESD)?

Did this ever happen to you?, after you touch something (or someone) 'Ouch'! you get a static electric shock. Can (any kind of) information be transmitted between two people during accidental ...
2
votes
2answers
94 views

Minimum information necessary to represent a pure quantum state

I was thinking about how quantum states are represented for various types of systems, and how the amount of classical information (bits) required to represent a state depends on its basis. Let's take ...
0
votes
0answers
47 views

Is spacetime information?

As I understand it, the information in a system is the totality of its properties that make its state uniquely identifiable. Examples I've seen are things such as the spin of each particle within the ...
2
votes
0answers
57 views

Consequences of Entropy/Information Reversal in a System?

Can pairs of different physical systems be symmetrical under a process which would turn one of these physical system's entropic and informational contents into another system's respective ...
8
votes
2answers
5k views

What is the relationship between Energy, Entropy, and Information?

What is the relationship between Energy, Entropy, and Information? I read this - What Is Energy? Where did it come from? - and the top answer says that 'energy' is an abstract number that is a ...
29
votes
4answers
3k views

Why do computers generate heat?

Computers generate heat when they work. Is it a result of information processing or friction (resistance)? Are these just different ways to describe the same thing? Or does some definite part of the ...