Information Definition and 999 Threads

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 =...

Recently read this article on Physorg: https://phys.org/news/2018-01-efficiency.html My questions are: 1. If "converting" information into energy requires a system (the demon I suppose) having a photodiode, processor, laser (light trap) all expending energy in order to cause the conversion...

Definition 1 The von Neumann entropy of a density matrix is given by $$S(\rho) := - Tr[\rho ln \rho] = H[\lambda (\rho)] $$ where ##H[\lambda (\rho)]## is the Shannon entropy of the set of probabilities ##\lambda (\rho)## (which are eigenvalues of the density operator ##\rho##). Definition 2 If...

I am applying to phd programs in physics right now. I am interested in doing research in quantum information science. I see there is a lot of interest and funding for quantum information science right now, but does anyone have any advice on whether or not this research will be well funded in the...

Hello All, To better qualify my question, I'm interested in finding a good online database, similar to SciFinder (which is a great resource for Chemistry researchers and engineers), but specifically aimed at EEs. With SciFinder, you can search for various topics in chemistry and it will scour...

hi, initially I am aware that AICc value is $$ -2(*log-likelihood)+2K+2K*(K+1)/(n-K-1)$$ where n is sample size and K is number of model parameters. But I really do not know how last term of right hand side is added, also AIC value is $$ -2*(log-likelihood)+2K$$ , so AICc has some correction in...

In the information loss paradox, people say that in quantum mechanics , time evolution is unitary. They usually do not say anything about the measurement process of if they do, they briefly say that the measurement process does not violate unitarity either if one takes into account the...

Hi everyone, I was watching Susskinsd's lectures posted on youtube about Quantum mechanics and he started explaining his -1st basic law of physics saying: the conservation of information means basically that if you start with 2 quantum states (vectors) which are observably different, or...

Imagine a (purely hypothetical) situation where someone proposes a scheme that exploits non-classical, nonlocal interference effects to transfer information between Alice and Bob. Apart from the accuracy and plausibility of the quantum mechanical part of the paper, would it be necessary for the...

Hello, layman here, I have a simple question, could you please clear this up for me? Whenever I read about the information paradox, it always appears to me that it is automatically assumed that quantum fluctuations / virtual particle pairs are predictably random. Which leads to the loss of...

Isnt the creation of information the same as the creation of mass, or energy, in other words, not possIble? If I am an electron and at time =0 , my position and velocity are x y z and p q r, how can i have gained information when my position and velocity at time T are x2 y2 z2 and p2 r2 q2? My...

See title.

I split this off a separate thread in response to a post of @Nugatory . The matter was about the (im)possibility of transfering information using entanglement. This is a basic thread, so I keep it simple: There are two particles/detectors, A and B. The particles are in the singlet state. My...

It is said that the measurement done on a particle instantly affects its entangled pair because Bell's theorem excludes a hidden variable. That means there is a cause and an instant effect at a distance. Say we have two entangled particles A and B. If there is no hidden variable then the state...

I'm not sure if I'm posting in the correct category. Please direct me to the correct one, if I have made a mistake. As I have mentioned in my intro, my knowledge of physics is almost non-existent. I am writing a book series, and I'm trying to base my ideas on science (more or less). This is one...

I read recently that no information comes out of a black hole. Doesn’t the mass information exit a Black hole with ease? Say I am orbiting a black hole and looking away. If while looking away the black hole gobbled up another star I could tell immediately that something had changed inside the...

I have posted this in University linear algebra, but it is possible there is a simple answer for this and the the problem belongs in some other forum. I apologize if that is the case. I am starting with 3 points in 3 space, along with the centroid of the full data set. The data is in principle...

Why is the quantity "information" missing from the SI system? Also, if they did add it, do you think it would be added as a base unit or dimensionless derived unit?

In compression of information, once any patterns have been 'condensed' as much as is possible, the information appears entirely random. Any further compression produces loss of information and the quantity of information required to encode it is increased. In one theory it is supposed that all...

Just what is Information. That is in Physics how is it conceived? Is it a particle a wave a field or is it another thing in nature entirely. When info is exchanged what is being exchanged Or is it just a maths concept that has no physical reality. Et cetera et cetera. I have looked at other...

We have two points A and B, separated by 10 light years away. WE have an iron tube conecting the two points, so this tube its 10 light years long. We are at point A and want to communicate with B, we have two options: -move slightly the iron tube---> instantly the observer at B will receive...

At one point I read there was the concern that a black hole could lose bits of information. Then a theory arose that showed that all the bits in a black hole were to be found on the surface of the black hole. Thus if there were let's say 1000 particles in a black hole each of which could be...

Having trouble with understanding this equation and its theory.

I have just started googling/youtubeing black holes. One point made repeatedly discussed is the loss of information in black holes. In particular quantum bits. What I have not yet found is very much explanation of what these potentially lost bits might be. So what I would like to know is...

Hello, I would really like a book like Susskind's "An Introduction To Black Holes, Information And The String Theory Revolution: The Holographic Universe" but not so condensed. If you have anything to suggest please do so. Also, if you know of any book that contains any part of the above book in...

What happens to the information entering to the Black hole??

Last year I've finished the undergraduate course in Mathematical-Physics and Mathematics and this year I've started on graduate school on Physics in order to obtain a master's degree. What I'm really interested are two main topics: general relativity and quantum field theory. I also like...

I saw this paper and would like some comments on it if possible. http://www.pnas.org/content/114/19/4920.full.pdf

What is the difference between how digital information encoded into a hard drive and how information is coded into DNA? It just seems strange to me how you are able to encode information/data into a physical object.

1-Whats the relationship between entropy and İnformation ? 2-Can Entrophy always increases statement imply information lost ? 3-If it implies how its lost ?

This paper; https://arxiv.org/abs/1704.08613, Entropy evolution of moving mirrors and the information loss problem, discusses a proposed method to test the information loss paradox posed by black hole evaporation. Several possible outcomes are discussed, including a firewall scenario...

<Moderator's note: thread spawned from this previous thread.> I have a question only loosely associated with any of the above, but that I hope may interest the minds behind this discussion. Does the apparent discovery and confirmation of gravity waves give us a source of information...