Information Definition and 999 Threads

Hi, I want to change the header of some document files like pdf, ms word, libre office programatically. I know that I have to use some byte type command like putc(..) and getc(). But I don't the header size of the above mentioned file formats.I saw a list of file format at wikipedia...

I can't seem to wrap my head around the notion of conservation of quantum information. One thing that might help that is if someone can tell me what the associated symmetry is. For example, phase symmetry leads to conservation of electric charge according to Noether's theorem; a fact that...

Anybody know more about this? It is in DISCUSSION forums since I do not see any decent references on the subject. Maybe I'm having a bad day... ##SF_{6}## - Prevents fires from electrical shorts, used in high kVa distribution lines - at connection points, substations, and "ties" Apparently...

Suppose I fire a photon with an upward spin towards a hydrogen atom. It is absorbed by the hydrogen atom's electron which subsequently emits a photon when it returns to its ground state. I then fire another photon with a downward spin towards the same hydrogen atom and the same thing happens...

I am 3rd year physics student (actually I have just finished it). I have good knowledge on basics of quantum mechanics: I had 1 semester of Introduction to Quantum Physics and then 2 semesters of Quantum Physics. Our literature were Griffiths (Introduction to Quantum Mechanics) and ''Gennaro...

I just wandering about the following hypotetical process to get some information from the inside of a black hole. 1. Drop a satellite into the black hole on a nearly tangential orbit. 2. After it crossed the event horizon drop a large mass after it (for example a small black hole). 3. This mass...

I'm sure that many PF members are fans of the seminal book The Visual Display of Quantitative Information by Edward R. Tufte But books on dead trees can only show static information. How about quanitative information depicted with the help of audio and/or video? I would like to nominate...

Did physicist John Archibald Wheeler propose the existence of multiple universes through his "It from Bit" or "Participatory Universe Principle" or "Law without Law and Pregeometry"? Is the multiverse related to Wheeler's ideas? I've been told that It can produce multiple universes, obviously...

In the context of a forecast, I am currently working on Fisher's formalism which is part of a more general theory, that of information. My problem applies to estimating cosmological parameters from input data with the Fisher formalism and recipes to build a Fisher matrix. The context is...

So I started from the heat governing equation above. There is no heat generation or matter flow, so I simplified it to dT/dt = A d^(2)T/dx^(2). Now I assume dT/dt = (278.15K-277.38K)/(1200s-900s) = 0.0025667. But then I'm stuck with the d^(2)T/dx^(2). Is the x just 0.20 m? For T I used 288.15K...

I have been asked to draft a (informal) research proposal for a PhD thesis. I have some background in quantum information and my interests are leaning towards the AdS/CFT correspondence. I was wondering if you could suggest a few (preferably recent) theory papers at the junction of quantum...

It seems that the way to combine the information given is z = f ( g ( (3r^3 - s^2), (re^s) ) ) we know that the multi-variable chain rule is (dz/dr) = (dz/dx)* dx/dr + (dz/dy)*dy/dr and (dz/ds) = (dz/dx)* dx/ds + (dz/dy)*dy/ds ---(Parentheses indicate partial derivative) other perhaps...

I am looking for information on a supposed prompt supercriticality event that occurred at ORNL while the MSRE reactor was running under Syd Ball. This incident was told to me by an engineer that is actively involved in reigniting interest in MSR based reactors. According to his summary, "Syd...

Other than with black holes, are there any other natural ways that quantum information can be lost, and thus jeopardize quantum determinism?

Hi everyone, initially let me introduce a concept widely used in ARIMA in the following. $$AICc = AIC + \frac {2k^2+2k} {n-k-1}$$ where n denotes the sample size and k denotes the number of parameters. Thus, AICc is essentially AIC with an extra penalty term for the number of parameters. Note...

The brain receives a lot of visual information some of which is redundant visual information. I am imagining it like the brain receiving a 1000 pixel wide by 1000 tall image of a road. The brain has received 1,000,000 bits/pixels of information. I am assuming the brain doesn't need all that...

Hi everyone, while I was digging arima model I saw that BIC value is given as $k*log(n)-2*log(L)$ where $L$ is the maximized value of likelihood function whereas $k$ is number of parameters. I have found the proof of AIC but no any clue about that. I wonder how it is derived. Could you help me...

I am a master student in theoretical physics from Italy and I would like to know more about fields related to "Quantum Information". I've been to some seminars and I think that these fields are very interesting, but I need to understand before applying for a PhD. What should I do?

Both the heat equation and the diffusion equation describe processes which are irreversible, because the equations have an odd time derivative. But how can these equations describe the real world when we know that all processes in nature are reversible, information is always conserved? But these...

Hello everyone! I would like to ask a rather comprehensive question. I would appreciate it if you could help me with this. I have started reading a chemistry textbook recently and typically in the first chapter of any basic chemistry course, you come across, measurement, unit conversion, etc...

Hello all: I need to ask this rocky question, if you want some funding for a research project and you are outside academic sphere currently , how to get it ? Where to apply ? And how to find team member, considering the project is a short one ? What about patents ? Best H

Is the problem with interpretations of quantum mechanics that one can describe the universe consisting of "stuff" that exists ontologically in different but conflicting ways, so that the universe can really only be described informationally instead of ontologically? That is: does the universe...

I have only recently started studying information theory and I am stuck even trying to understand the basic problem and concept of information theory. My question is why does information need a probability? I have read some text that starts by introducing the idea that the amount of information...

There are two aspects of uncertainty (a) how far different from the situation where all possibilities are of equal probability (b) how spread out the values are. In discussions about (Shannon) entropy and information, the first aspect is emphasized, whereas in discussions about the standard...

If they could solve the information loss paradox in black hole https://en.wikipedia.org/wiki/Black_hole_information_paradox What other related problems it could solve in Beyond Standard Models or unsolved quantum questions, etc.? If the LHC could no longer detect new particles, could beyond...

More specfically can time be defined as information being passed from particle to particle?

Hi all, I don’t know if posts like this are allowed and if not mods please remove but I am currently enrolled in Gen Physics 1 w/Calc(I don't know why I challenged myself with this class when normal Physics 1 would’ve worked for me as a biochem major) and am struggling to do understand the...

Hi, I’m interested in self studying so that I can learn / understand integrated information theory about counciousness. I was wondering if anyone could help me identify what courses (I’m looking at using MIT’s opencourseware to study although just types of math is all that is needed) I would...

So I have been trying to derive peukerts exponent based on assumptions I know this won't be accurate but I am curious about the data. So I don't know the time to discharge the battery so I guessed 3 Hours the capacity at a 20 hour rate is 40Ah meaning the manufacturer rated discharge current was...

Could information in a boundary be modified once encoded in holographic principle?There are models of universes where holographic principle has a different correspondence (there is absolutely no reason to assume that this would hold true for all possible universes. You could have a universe...

If this is not in the correct area please move it as I am not sure. Also the same with the prefix. I have searched this on the forum and could not find anything relating to it. https://phys.org/news/2018-09-scientists-mechanism-storage-atom.html

Suppose you measure the spin of an electron along some axis, we get the result +1 with probability 0.5 and -1 with probability 0.5. The average information we receive is 1 bit of information. Now if we rotate our apparatus 90 degrees and make a new measurement, we will as before get the value +1...

I have a question about black holes. So imagine that we start putting energy in some region of space, until we reach Schwarzschild radius. We also reach the maximum amount of information we can store in that region of space. Still, the energy continues to collapse in smaller and smaller space...

I'm working with Aerodesign, and I want to study "Inertial loads" but I can't find books about the subject, do you know any? thank you

So let me preface this by saving, I am a computer programmer, not a physicist, and the main reason I became interested in quantum mechanics has a lot to do with the recent developments in quantum computing and quantum entanglement in general, although I do have a lot of curiosity about the inner...

Where in this though-experiment do I get it wrong? Even though no mass can travel faster then c, maybe information can? And I'm not talking about quantum entanglement etc. Consider a pipe, filled with balls that are very tightly arranged. If I push the outermost ball on one side of the pipe...

So I read a couple of explanations of how night-vision equipment works. Unfortunately I don't remember the sources but my recollection/understanding is that infrared light is converted into electrons and then into visible light. So my question is how does the information by which I mean (the...

For ex. if two particles close to each other require n bits of info to describe them, why does it take n bits to describe them when they are far apart? Shouldn't the information content be the same for the macrosystem?

My guess is the number is huge,but I don't know what transformations from the hip Iwould use to figure this out.

Hey Everyone! So disclaimer, I'm not involved with physics professionally or educationally, it's just a hobby I like to think about, so please excuse my ignorance :). Anyway, I had a thought, and I was wondering if you guys could elucidate it. Imagine that we have a hypothetical telescope...

Greg Bernhardt submitted a new PF Insights post How to Better Define Information in Physics Continue reading the Original PF Insights Post.

Having in mind the idea that "information is not lost" (referring to the black hole information paradox), is not the same rule violated in the wave function collapse? I.e. during the decoherence process information is not lost as this process of entanglement of some object with its environment...

So let suppose I have a random variable Y that is defined as follows: $$Y=\alpha x+ \mathcal{N}(\mu,\sigma) \text{ where } x \text{ } \epsilon \text{ }\mathbb {R}$$ and $$\mathcal{N}(\mu,\sigma)\text{ is a i.i.d. normally distributed random variable with mean }\mu\text{ and variance }\sigma$$ So...

Let's say I have a ball 299792458m away and i want to apply a force to it. Evidently any information (for eg if i instantaneously increase my mass to increase the gravitational force) will travel at the speed of light and thus, the increase in gravitational force will only be felt by the ball 1...

Stephen Hawking proposed that black holes will eventually evaporate due to Hawking radiation, thus all information eaten by the black hole is destroyed. This violates basic physics, and hawking soon recanted his views, but there is still no real answer to whether they do or don't destroy...

I'm a math major interested in the field of quantum information science and quantum computing, but I'm unclear on what path to take to explore the field. The field is presented as being at the intersection of physics, computer science, and mathematics but it seems that a majority of the experts...

Suppose we have a quantum system ##Q## with an initial state ##\rho^{(Q)}##. The measurement process will involve two additional quantum systems: an apparatus system ##A## and an environment system ##E##. We suppose that the system ##Q## is initially prepared in the state ##\rho_{k}^{(Q)}## with...

Homework Statement Is the following conclusion correct? Assume there's an equation with vectors on both sides. Taking the dot product of this equation with vectors on both sides loses information, but information will not lose when taking dot products with higher rank tensors on both sides...

Can whatever type of information be encoded in a boundary in holographic principle? in a question some years ago regarding holography (https://physics.stackexchange.com/questions/75436/are-stokes-theorem-and-gausss-theorem-examples-of-the-holographic-principle) It is said that AdS/CFT is the...

I am interested in defining Krauss operators which allow you to define quantum measurements peaked at some basis state. To this end I am considering the Normal Distribution. Consider a finite set of basis states ##\{ |x \rangle\}_x## and a set of quantum measurement operators of the form $$A_C =...