Information Definition and 999 Threads

Homework Statement A string vibrates at its third-harmonic frequency. The displacement at a point 59.0cm from one end is the first time the displacement is half the maximum amplitude. How long is the string? Homework Equations wavelength=(2(rope length))/nodes y=Asin(kx) k=2pi/wavelength...

Hi I'm having some trouble understanding Shannon entropy and its relation to "computer" bits (zeros and ones). Shannon entropy of a random variable is (assume b=2 so that we work in bits) and everywhere I've read says it is "the number of bits on the average required to describe the random...

Is there any theory that says anti-information exists? If there is anti-matter, would that matter carry information to annihilate the regular matter's information saying its a certain type of matter and turn it into energy? Could anti-matter just be regular matter with anti-information.

Hi everyone, Hoping someone can give me insight on this. I am visiting two schools next week - CU Boulder and University of Maryland, both of which I have been accepted to for quantum information experiment (PhD.) Both are very highly ranked and seem to have great departments, and I'm...

I have been asked to find a way to integrate our DSC instrument into a teaching laboratory. I have read through some articles on the Journal of Chemical Education and I have a good idea on what to do as far as content goes, but there are some particulars about the instrument that I'm unsure of...

Hi Folks, Can somenone explain what "information" is with respect to black holes? I thought it was all about mass and energy from both quantum Mechanics and GR perspective. Why does "information" come into it...sounds unusual to say the least. Thanks B

If the torsion of the straight line is undefined what happens with the information about the torsion? It is known (https://en.wikipedia.org/wiki/Quantum_no-deleting_theorem, http://van.physics.illinois.edu/qa/listing.php?id=24045) that the information conserved in a system can be nor created...

I met with a professor/teacher advisor for the CIS (Information Systems) major. They said it's probably not for me, based on my career intentions. I'm intending to start a startup IT corporation ASAP as a career. I need the knowledge of (many, several) programming languages for my intentions...

Homework Statement Let X1, X2,...Xn be a random sample from pdf, f(x|θ) = θx-2 where 0 < θ ≤ x < ∞ Find the MLE of θMy attempt: Likelihood fxn: L(θ|x) = ∏θx-2 = θn∏ θx-2 And to find MLE, I take Log of that function and partial derivative (w.r.t θ, of log L(θ|x) and set that = 0, and get...

Leonard Susskind says so. But I don't see it. Yes, the present "here and now" is computed by nature from the events lying in its past light cone + the laws of nature. If we assume a deterministic universe, the present "here and now" contains the information from the events in its past light...

Hello..What do you think of the course Electronic and Information engineering course? Is it a good course for industry? I don't know much about this field. I would like to do master in computer science/engineering or electrical related fields. Is it a good degree? These are the modules: -...

I need to give a presentation about roger bacon (the guy who said that rainbows form at a 42 degree angle). It's hard to find information about his study of rainbows so if anyone knows something about it I'll be grateful.

Hi. From an outside observer's view, any object approaching the event horizon of a black hole appears to slow down and never quite pass through the horizon. So information about those objects can always be retrieved (if you correct for the redshift). So what actually is the information paradox...

You perform a double slit experiment, detecting the photons at the slit, and storing, but not observing, that data on a memory stick. The pattern on the screen is also stored, but not observed. Person A travels with the memory stick to New Zealand and person B travels to London with the...

[I originally posted this in Astronomy and Astrophysics but it didn't get much traction. Perhaps folks in this forum would have something to contribute...] I'd like to understand if and when information is ever actually lost in a black hole; specifically, I'd like to analyze the statement: Is...

[Mentor's note: Split off from https://www.physicsforums.com/threads/an-abstract-long-distance-correlation-experiment.852684/page-6 because this subthread was discussing possible mechanisms behind the phenomenon] My take on these: 1) - not weird at all - you send a photon in one direction...

I'd like to understand if and when information is ever actually lost in a black hole; specifically, I'd like to analyze the statement: Is there information, which existed in the past, that is theoretically unavailable to external observers today due to falling through the event horizon of a...

Hello, I have a question: let's assume that some photons are passing ~10m pupil, like in largest telescopes. Are they EXACTLY identical AFTER passing, than before? Or is there some lost of infromation becouse most part of their wavefront is cutted off and we only register ~10m part of it (from...

Hello, It is my desire to build a functioning robot & start a company called Applied Robotics. I would like to use the IBM TrueNorth processor, however I am not able to get IBM to respond to my requests for info. They have even created a send in form but do not respond to it. Does anyone know...

I have just seen a brief clip of an article by a journalist regarding a lecture given by Hawking this week about the mystery of where information of a star goes to when it is swallowed by a black hole. As a non physicist, I am grappling with what exactly is meant by this. Isn't this just a...

Hi everyone I need help understanding the lines on the attached picture. In the proof of corollary 14 how does it follow from corollary 13 that: Λ(X) = ∑li><il Tr[KijXKij†] I think what has been done is take a partial trace over the system HB, but what exactly is the effect of this? It says...

I recently attended a talk about molecular clouds discussing CO transitions in them. I've been trying to understand spectroscopy in astronomy and have tried reading lots of articles online although I still don't quite get everything. It seems that telescopes can find the intensity emitted by...

Hi, guys, I am an undergraduate pursuing electronics and communication in her 3rd year. For last few months, I have been trying to obtain internships in the field of quantum information so that I could have more exposure to it. I am already pursuing the subject learning it in bits by bits and...

I'm a biologist interested in physics. Biology is undergoing several revolutionary changes, but physics is interesting too! I am interested in the physical aspects of information processing in biological entities, things like: genetic control systems, information transmission through...

Hi. I have no significant pure physics or math education or work experience (retired corporate analyst) but I was wondering what experts here might think about the relations between energy, dark energy and information. My understanding is that dark energy is the expansion of space, with space...

Is it possible to find the pressure of water that leaves a pipe of certain area/diameter given only the flow rate of the water itself? OR the requires piping diameter/area given the pressure that I desire. I'm trying to design a system that requires relatively high pressure (for spraying)...

According to the EPR-paradox, if we have a pair of two entangled spin-1/2 fermions A and B and measure z-component of A, B collapses immediately as well(i'm using these letters for both particles and their observers). The 'canonical' solution is then to state that it is not possible to transfer...

I am doing my undergrad research on Dark Matter and Dark Matter but have only few links of sources. Are there any online info-stores where I can get most of the discovered information on them. All related research papers and the different properties discovered about Dark Matter and Dark Energy...

Would a perfectly ordered crystal in an isolated system with no temperature be able to store information that can be used to predict the future of that system? I am asking this question with the Big Bang in mind: intuitively, it appears to me that at the beginning of the universe there should...

I would appreciate any clarification (or opinion) on the relationship between Quantum Numbers and Quantum Information. My question is related to the puzzle wether matter merely represents information or - at the basement level of reality - actually can be said to be information. Just to give...

Does anyone know anything about quantum information theory? I am reading a text about transmitting quantum states, represented by density matrices, through channels. Here the depolarising channel is defined as the map: X: -> (1-p)X + pτ Tr[X] which with probability (1-p) maps the state onto...

Dear PF Forum, I'm interested in environment. And I want to know about nuclear power plant waste. In fission reaction: Neutron + U235 -> Kr 92 + 141 Ba + 3 free neutrons. What is the radioactive waste in fission power? Is it in the result Kr92 and 141 Barium? Is it in the 3 free neutrons? Where...

In both cases there are contrast agents available. MRI has vastly superior location error but that doesn't mean everything. It also doesn't illuminate the tissue in the same way as x-ray optics. With MRI you can find where molecules are but wouldn't necessarily illuminate an equivalent density...

Hi everyone, I'm looking for websites that provide information on what a nanoparticle is and which explain the physics of how its structure remains stable. Can anyone recommend a site or more that explain it as simple as possible, in a manner that is understandable for non-scientist? Thank you!

I'm very confused as to how qubits function. I understand that qubits can represent 2^n classical bits due to superposition, but I cannot find an explanation as to how the qubit can "parallel process" if you will. How could the qubit represent 2^n bits if, whenever it is measured, you still...

Hello, I am currently a grade 12 high school student and I am doing a project for my physics class on aerospace engineering. In order for me to get a good mark on this project I need an interview with an aerospace engineer. I would simply be asking one questions like what they do on a daily...

I've built a rod 186K miles long, of ultra-light, ultra-rigid material. I am on one end of the rod, and an observer is at the other end (we're both in the near vacuum of space). I want to send a signal to the observer on the other end of the rod signaling whether the Packers have won the...

Hello, I need to work on the thermodynamics theory of information, but I can't find real applications aside from the resolution of the maxwell's demon and the szilard engine. I would need more applications... Any idea?

If photons are the force carrier of the EM force, and they have no charge, how do they give the information between two charged particles? How would a proton know the difference between a electron and positron?

I am reading a book called 'quantum processes systems and information' and in the beggining a basic idea of information is set out in the following way. If information is coded in 'bits', each of which have two possible states, then the number of possible different messages/'values' that can be...

Can you please explain what the core problem of the information paradox is? Hi all! I've read many articles about it, watched videos, argued with some physicists, and yet I can't grasp at all where the paradox lies. For example, from the Wikipedia: "An important difference between the black...

Homework Statement 1 mm3 of gas at normal pressure and temperature contains about 1015 particles. Considering the particles as point-like and classical, provide a rough, conservative estimate for how many hard drives would be necessary to store the initial conditions of all gas particles. (As...

Hello, I have to work on the relation between the thermodynamics and the information theory on both historical and theoretical aspects. My work will not contain proof. It will contain the most important equations and descriptive paragraphs. I need to talk about the relation between Clausius and...

I have been looking for literature on this question but can not find any, will a (bounce) retain all the information of the previous galaxy ?

Let's say I encode all the information in some book in a light beam. Then I put a black hole in the way of the beam. Mass and information of the black hole increase as the beam plunges in the black hole. But what if the black hole is moving very fast parallel to the beam? In this case the rest...

I just read this article: http://abcnews.go.com/Technology/plutos-majestic-mountains-atmospheric-haze-revealed-photo-horizons/story?id=33832751 The article itself is really cool, but something at the bottom of it caught my attention. I don't know how fast New Horizons is traveling, but say...

A single electron is fired at a detector, what do we know about the electron after it reaches the detector that we did not know before.

Searches of PF archives for Information Conservation turn up many threads in which the question is more or less dismissed. It sounds like many PF regulars don't believe in it, as if it were fringe science or metaphysics. Contrast that with the prominence given to the recent thread Stephen...

Need a little assistance, and yes I should know how to answer this but... The project is from an Oil and Gas system. Deadline anchor and load cell. a reel has wire rope on it that acts on an arm that puts pressure on a load cell. I'm trying to back calculate the force in lbs on the wire rope...

Homework Statement An electron falls through a distance of 1.5 cm in a uniform electric field of magnitude 2.0 x https://www.physicsforums.com/callto:104 N C-1. The direction of the field is reversed keeping its magnitude unchanged and a proton falls through the same distance . Compute the...