Information Definition and 999 Threads

  1. O

    Nearly Perfect Efficiency - 2nd Law of Thermodynamics

    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...
  2. Danny Boy

    A Von Neumann Entropy of a joint state

    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...
  3. ExplosivePete

    Physics Is quantum information research well funded?

    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...
  4. J

    Good Online Database for EE Research information

    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...
  5. mertcan

    A Akaike information small sample AICc

    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...
  6. K

    A A question about the information loss paradox

    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...
  7. S

    I What is the Conservation of Information in Quantum Mechanics?

    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...
  8. S

    Relativity's role in forbidding FTL Information Transfer

    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...
  9. A

    B Black hole information paradox and determinism

    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...
  10. D

    I How can information possibly be created?

    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...
  11. entropy1

    B Information transfer using entanglement?

    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...
  12. C

    I Quantum entanglement information

    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...
  13. N

    Information transfer in space - with book research

    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...
  14. T

    B Can we detect changes inside a black hole through orbits?

    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...
  15. L

    MHB Find XYZ for Tip of Vector Given Info on 2 Other Vectors w/ Tails at Same Point

    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...
  16. Nim

    I Why Is There No SI Unit For Information?

    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?
  17. B

    B Big Crunch, Big Bang and information loss

    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...
  18. P

    I Just what is information, and what is its place in Nature

    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...
  19. J

    B Send Information Faster than Light: Point A to B

    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...
  20. A

    I Information for black hole region in surface surrounding it

    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...
  21. A

    I Explain about the information lost through black hole

    Having trouble with understanding this equation and its theory.
  22. A

    I Quantum bits information lost in black holes

    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...
  23. J

    Cosmology Book on Black Holes, Strings, AdS/CFT

    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...
  24. STAR GIRL

    I What happens to the information entering a Black hole?

    What happens to the information entering to the Black hole??
  25. L

    Other Quantum Information and General Relativity

    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...
  26. cosmik debris

    A Counterfactual Transmission of Information

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

    Question about the encoding of information

    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.
  28. Arman777

    I Information Theory and Entropy

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

    I Testing the information loss problem

    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...
  30. A

    B Transmitting information using gravitational waves

    <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...
  31. thrasher1031

    Need some information about Shell Sort

    Hello everyone, i was wondering if anyone knows which uses or applications has Shell Sort and what are the advantages and disadvantages of this sorting method. So far i can't find a lot of information on the applications only that is used in some form in the Linux Kernel and on a library from C...
  32. rnk

    I Delayed choice quantum eraser - partial information retrieval

    In Delayed choice quantum eraser experiment (https://en.wikipedia.org/wiki/Delayed_choice_quantum_eraser) entangled photons are sent on different paths. They reach their detectors at different times. The one arriving early is called a signal photon. The photon that arrives at its destination at...
  33. *now*

    Meaning = Information + Evolution

    This paper offers a "first link of a chain", bridging physical and, psychological or linguistically, mental notions of meaningful information. https://arxiv.org/pdf/1611.02420.pdf Meaning = Information + Evolution Carlo Rovelli CPT, Aix-Marseille Universit ́e, Universit ́e de Toulon, CNRS...
  34. Delta Force

    Seeking Information on the Orkney Uranium Deposit

    Apparently there is a major uranium deposit at Orkney in the United Kingdom that might also be very high grade (the article seems to indicate it is 50.2% grade, which would be even higher grade than Canada's deposits). I've found a lot of information on the controversy surrounding potential...
  35. B

    B Information paradox in black holes

    I have always been fascinated with black holes and information paradox. If quantum bits made up spacetime. Could the information getting inside a black hole be possibility encoded in its quantum bits? Look at https://www.quantamagazine.org/20150428-how-quantum-pairs-stitch-space-time/
  36. E

    Does the Wavefunction Collapse Violate Information Conservation?

    I have read that "Information is conserved", or at least that it should be. I read this in some discussion about whether or not black holes destroy information. (ref: Leonard Susskind, Stephen Hawking, The Black Hole War, etc..) It is believed systems in distinct states evolve into distinct...
  37. M

    MHB What is a geometric interpretation of all these information?

    Hey! :o We have the tableau $\begin{pmatrix} \left.\begin{matrix} 1 & 0 & \alpha \\ 0 & 1 & \beta \\ 0 & 0 & 0 \end{matrix}\right|\begin{matrix} c\\ d\\ 0 \end{matrix} \end{pmatrix}$ Since there is a zero-row, we conclude that the column vectors are linearly dependent. The number...
  38. Dadface

    Can arXiv papers be considered as reliable sources of information?

    Is it correct to assume that, in general, authors who have papers accepted by arXiv eventually try to get their work published in a journal? If so what should we make of arXiv papers which apparently do not get accepted by any journals? Should we take those papers as seriously as we would take a...
  39. Ron19932017

    I End point information in lagrangain variation principle

    In lagrangian variation we are trying to minimize the action S = ∫t2t1 L dt. Consider a simple case of free particle. Imagine In a world that everyone one only knows how to solve ODE, Using euler lagrange equation, one has d2x/dt2 = 0 , give that we know the initial position of particle in the...
  40. Maximilian Popelier

    What Are G Forces on a Jet and How to Calculate Them in a Turn?

    Hi, do you guys got information about g forces on a jet and maybe exercise and ansers where you need to calculate the g force in a turn? ty for the help Maximilian Popelier
  41. Viopia

    B Double slit experiment -- consciousness and information

    I am not a physicist but I am interested in the double slit experiment and would like a definitive answer, from a physicist, to my question as follows:. If the which path is just detected by a detector, without it flashing and bleeping at the same time, and without the detections being recorded...
  42. stevendaryl

    A Information Paradox for Unruh Radiation?

    I'm sure that there are limits to the analogy between the event horizon of black holes and the "Rindler horizon" for an accelerated observer, but there are a number of similarities: For Schwarzschild spacetime as described in Schwarzschild coordinates: Spacetime is static, and a rocket must...
  43. B

    Question about information on a disc

    When you load a game from a disc into an Xbox 360, example being Call of Duty, what is the information on the disc classified as? Is it just a different form of application software like Google Chrome or are you just loading a bunch of game files from the disc?
  44. AlexSH

    Conservation of Information and indeterminism?

    I just recently learned about Leonard Susskind's work on conservation of information. From what I've read and from his lectures, conservation of information and the holographic principle are based on the reversibility of physical laws. Reversibility in turn implies determinism, so if...
  45. wolram

    B Does information travel faster than light

    https://www.sciencedaily.com/releases/2012/10/121028142217.htm Usable or not this seems to be a spooky statement can this 10000 be falsified?. Experiments have already shown that if you want to invoke signals to explain things, the signals would have to be traveling faster than light -- more...
  46. B

    Question About Digital Information

    Is digital information that travels across the internet massless? If we were to take out the cables(and maybe the electrons)from the equation, is the digital information taking up physical space?
  47. mesa

    Looking for information on Celanese Fortiflex polymer

    Hey guys, I am trying to located more information on a polymer that was called celanese fortiflex. It was used in TRIGA nuclear reactors to hold samples in a high neutron flux and was developed (I believe) around the early 1960's. Some modern PE materials have been tested, but fall apart after...
  48. T

    I What is the required amount of information to specify an element in \omega_1?

    To select an element from countably infinite set (list set of integers) you need to provide finite amount of information. To specify an element in continuum in general case you have to provide infinite amount of information: any real number is specified as countable-infinite number of digits. So...
  49. newjerseyrunner

    I Is it possible to send information with entanglement?

    I'm not asking about two way or even repeating communication. Is it possible to entangle particles, keep then entangled and send half of them far away, and delay their choice for an arbitrary amount of time? What I'm thinking about is asking a yes or no question: Is there life on Planet X? So...
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