Information Definition and 999 Threads

Hi all! I would like to learn the basics of information theory and want a good book to do so. My math level is that of a second year undergraduate physics student, but I don't mind if I have to struggle a bit through it. Thanks!

Hello, Is anyone familiar with GIS? I'm thinking about switching for my BS then doing an MS or PHD. Does anyone know how these skills support other fields in the private sector or goverment? Also I want to do something 'sciencey'...so how 'sciencey' is it?

Hi there! I'm new here and have a pretty basic and maybe stupid question: What exactly does one mean when talking about "truth information"? I'm working with a simulation of a particle detector and I've been trying to make sense out of all the data that is stored in the ouput files. Words like...

In many experiments that show quantum effects particles are given the option to take different paths/routes. This is done using devices that act as mirrors/splitters/joiners/etc. Probably the most famous of these type of experiments is the Delayed Choice Quantum Eraser, but there are many...

I just got Pinter's book, "A Book of Abstract Algebra", for the modern algebra course that I'm taking. It's a very nice book, I'm enjoying reading through it so far. What's especially interesting is the connections to computer science and controls, mostly because I switched to math and physics...

TL;DR I want to warn readers (non-physicists) of my blog that it is wrong to claim that erasing or not detecting "which-path" information in DS and DCQE experiments is the same as turning off your recording device or deleting a data file on your PC, and it is wrong to assume that the particle...

I could have also titled this thread so much to learn, so little time. I don't know what to do, I really want to get into QCD and M-theory, but I know I need a lot more prereq's before I get to that point. I am feeling really impatient, however. and that's led me to try to get into a lot of...

Hello^^ It's always interesting to ponder the various ways that quantum entanglement *appears* to allow transmission of faster-than-light information, but on closer examination, actually doesn't. One that occurred to me today was the situation of two persons who receive each of a pair of...

http://arxiv.org/pdf/1401.5761v1.pdf Abstract: It has been suggested that the resolution of the information paradox for evaporating black holes is that the holes are surrounded by firewalls, bolts of outgoing radiation that would destroy any infalling observer. Such firewalls would break the...

I think about the following: For a black hole it seems quite natural to reflect about information loss. May be we have a firewall etc. We have an event horizont which does not allow any information exchange with the outer world. The difference between the universe and the singularity might be...

When electromagenetic wave is produced by dipole antenna, all the space exist EM waves like torus with different amplitude. Even though waves could reach destination, then how to decode information within it?

Hello all, I am trying to locate information on the following painting: Information either about the name of the artist or location of the painting is what I am after. I have searched high and low but have found nothing (and the signature is very difficult to read). I am at my wits end, so...

Hi all, 1. Homework Statement http://imgur.com/kqZK1Vv This is the loop gain (A.F.) of unity feedback system. I need to extract DC Gain Bandwidth GBW (is GBW Gain Bandwith ?) f unity (I suppose this is unity frequency) Phase Margin Gain Margin What is the optimal PM and f2/GBW for time and...

[Mentor's note: Edited to fix an error in the title] I hope to know where does this definition come from. Thank you very much.

I hope I've searched the forums thoroughly enough, I didn't find a similar question. I'm wondering about the specifics of the speed of the information on change in B of the solenoid between the two paths in a double-slit setup, one large enough where relativistic speed effects are within a...

(sorry for quality of the drawing) There are 2 accelerating observers, A and B in the infinite and asymptotically flat universe. When accelerating both A and B observe Unruh radiation from their Rindler horizon. If there is a cold screen between observer B and his horizon, B detects less Unruh...

Hey everyone, I just got my admission from the following programs: MSc Mathematical Physics --Edinburgh MSc Theoretical Physics -- Durham MSc Quantum Fields and Fundamental Forces -- IC I have a BSc in Mathematical Science, and I wish to continue a Phd study in particle physics and cosmology...

In Euclidean geometry (presumably also in non-Euclidean geometry), the part of the dissecting line that dissects the vertex angle and is inside the isosceles triangle is shorter than the legs of the isosceles triangle. Let ABC be an isosceles triangle with AB being the base. Then, for...

Question! So Alice falls into a black hole, instead of the volume increasing for the black hole, it actually increases proportional to it's area. Thus one can draw the conclusion that 3 dimensional information can be fully explained by the information encoded on the surface area at the boundary...

If the sun suddenly vanished, hypothetically ceased to exist. Would the Earth still continue on its circular path for 8 min 20 sec? and then leave its orbit tangentially?

Homework Statement A dog of mass M is standing on a raft so that he is a distance L from the shore. He walks a distance d on the boat toward the shore and then stops. The boats has a mass of Mb. Assume no fricton between the boat and the water. How far is the dog from shore when he stops...

Reading about the concept of 'information' in physics, I have often read the Shannon definition of information contents, i.e. how compressible the description of something is. A truly random number can not be expressed in any shorter way than itself, thus having a high information contents...

Hello guys, The units for acceleration is ms-2, does this mean that for every second the speed is increasing by x ms-1? Also can acceleration be used for speed and velocity since speed is distance/time while velocity is displacement/time? Thanks

hello , any one give me an information that how i make my own 8" telescope...And for making telescope which instuments are require

As far as i know CPUs consume power because of the ohmic resistance of the transistors that they are built of(i hope i am not wrong on this). But if we were able to build some sort of superconducting CPU with almost zero ohmic resistances, would it be able to operate and perform computations...

Lenoard Susskind's video courses on Clasical Mechanics and Quantum Mechanics, often mention convervation of information. Susskind likes to call it "the minus first law." In classical physics, it is Liouville's Theorum which tells us that the number of states is conserved in time evolutions...

Imagine a maximum entropy information system: This system would hold meaningful information, not just random noise, but still be of maximum possible entropy in the sense that you could randomly change the order of the smallest bits of information in it without actually changing the overall...

Imagine an uncharged solid spherical conductor. Inside this spherical conductor, there is a cavity of a weird shape carved out of it. And somewhere inside this cavity, there is a charge +q. The charge +q induces an opposite charge -q on the wall of the cavity of the conductor, which distributes...

Hey guys Do you have some info about quantum...genetics? Cuz I've seen a book on it but it's £50 so I read an article about some professor at MIT interviewing his about this. So do you have any info, knowledge, material on that subject? Thanks.

Homework Statement I've tried to attached the image of the diagram. If that isn't working please let me know.Height of incident marginal ray now 25. Assume a thin lens. Find: a. the effective focal length b. the power of the lens c. surface curvature for front and back surfaces (assume...

In section IIIA (p11) Max Tegmark tries to prove that the integrated information Φ of a bell state is zero. The definition of Φ that Tegmark uses is given by the mutual information I minimized over all possible factorizations. The bell state has I=2 when written in the usual basis. Tegmark...

Homework Statement Homework Equations Please see below. The Attempt at a Solution From my thread in the Solid State section (and input from DrDu): The Thomas-Fermi wavevector relates to the damping of an electric field caused by build up of carriers around an impurity (screening). Where...

Hydrogen - Halpha cross section i need the absorption cross section for the absorption of an H-alpha photon by a hydrogen atom, in the correct state of course, which I'm pretty sure is neutral hydrogen, n=2. I am needing this for a project, so i also need a reliable source where this comes...

One of the important problems in modern physics is BH information paradox, which is the problem with non-unitarity of Hawking radiation. But now there is this paper which says that this process is actually unitary and so BH information paradox is, not solved, but dismissed. I'm posting this...

Hey everyone. I'm sorry if I'm posting something irrelevant here. I really don't know where to ask this question but this hit me while learning Computing Principles (It's my first day in college). I'm one who is interested in physics too. Hence, I got a little confused about the term...

The smallest unit of information is a bit, which has two possible states. Yet don't you also have to specify the location of this information? So in a 4d world we're talking about 4 + 1 = 5 degrees of freedom, or 5 bits of information to code for just the one bit. So is there really such...

Did they read the recent physics papers about the atoms? Overall what sources of information did the old Manhatten Project Scientist like Edward Teller and Robert Oppenheimer use? I bet they must have really enjoyed what they did to be so good at it.

Does entropy increase during spontaneous emission? If not, how is the information about the emitted photon mode encoded into the initial state of the atom (and/or environment)? If so, where does the extra information come from?

What limits the speed of information through a copper wire? What is the speed of signal in optic fibres? Is it faster and why?

Given five data points (minimum, 25th percentile, 50th percentile, 75th percentile, maximum), do I have enough information to be able to construct what a normal (Gaussian) distribution would look like? I have no data on any other statistical information (population size, mean, median, mode...

Hi I'm debating a creationist and he makes the claim that no DNA can be added to a genome. Says there are no experiments. Can someone help me with concepts or sources to experiments? Thanks

Hello, I bought 20x50 (150m/1000) binoculars that were not expensive from untrusted market but they were relatively cheap. But when I decided to sell them to another person he told that they zoom no more than 12 or even less. I don't understand how magnification is calculated. I didn't thought...

Hi I am doing an assignment where I roll a tin can filled with car oil. This will affect its rolling because it distorts its centre of mass, resulting in an awkward rolling motion. I have already done the experiment, the first revolution is the slowest one by a lot because it slows down a lot...

The National Academy of Future Scientists and Technologists That's the full title of the organization, does anyone know if it is a legitimate organization? I got really excited when I saw, but then when I looked it up on the internet I found a lot of people asking if it was legitimate and there...

This has been on my mind for some time now. I recently read this article and it really got me thinking: http://www.ctvnews.ca/mobile/sci-tech/scientists-debate-sending-out-signals-for-alien-life-1.2235312 The Voyagers will soon drift into the far reaches of interstellar space, and NASA has...

I want to see if anyone has worked with this or know anything about this type of material? I am looking into particular the coating process of materials I.E. steel. Looking for processes and material specs. Any help would greatly be appreciated. Thanks

Homework Statement "If a soft-drink bottle whose volume is 1.50 L is completely filled with water and then frozen to -10 degrees Celsius, what volume does the ice occupy? Water has a density of 0.997 g/cm^3 at 25 degrees Celsius; ice has a density of 0.917 g/cm^3 at -10 degrees Celsius."...

Stuck on another calculus question and not sure where to begin: For each h(x) defined below, find h′(2), given that f(2)=−3,g(2)=3,f′(2)=−3 and g′(2)=7. a) h(x)=f(x)g(x) b) h(x)=g(x)/1+f(x) c) h(x)=x^2/f(x) d) h(x)=g(x)/x^2 Thanks for all your help. Sorry for bombarding but...

I have a question about, perhaps, GCSE level physics, if not below, which, for some reason, is not explained anywhere I've looked up. Or, at least, I didn't find any explanation. The picture above is supposed to explain the concept of superposition. It depicts a pair of one-dimensional waves...

Homework Statement [/B] Consider the missing information function ##S(\left\{p_i\right\}) = -k \sum_{i=1}^r p_i \ln p_i## where ##\left\{p_i\right\}## represents the probabilities associated with the ##r## mutually exclusive outcomes of some procedure. i) Sketch the form of S as a function of...