What is Symbols: Definition and 292 Discussions

A symbol is a mark, sign, or word that indicates, signifies, or is understood as representing an idea, object, or relationship. Symbols allow people to go beyond what is known or seen by creating linkages between otherwise very different concepts and experiences. All communication (and data processing) is achieved through the use of symbols. Symbols take the form of words, sounds, gestures, ideas, or visual images and are used to convey other ideas and beliefs. For example, a red octagon is a common symbol for "STOP"; on maps, blue lines often represent rivers; and a red rose often symbolizes love and compassion. Numerals are symbols for numbers; letters of an alphabet may be symbols for certain phonemes; and personal names are symbols representing individuals. The variable 'x', in a mathematical equation, may symbolize the position of a particle in space.
The academic study of symbols is semiotics. In cartography, an organized collection of symbols forms a legend for a map.

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  1. F

    Medical Synesthesia, some people perceive individual symbols, characters, numbers

    http://en.wikipedia.org/wiki/Synesthesia#People_with_synesthesia I found this facinating. It seems some people percieve individual symbols, characters, numbers, and letters as having their own color. Not only that, but it appears there can be any number of mixing of the senses. Perhaps...
  2. Z

    Christoffel Symbols: Intuitive Proof for Covariant Derivative of Metric Tensor

    I am learning about christoffel symbols and there is a pretty standard representation of christoffel symbols as a linear combination of products of the metric tensor and the metric tensors derivative. However when this is derived it is always done in a hoakey manner. Something along the lines of...
  3. P

    P&ID Symbols Reference Textbook or similar

    To the viewer of this post, What is a good source for the symbols used in a P&ID? I would like to have a textbook or similar which would have all (if possible, or a majority) which I could easily reference to now and in the future when drawing/analysis P&ID's. Kind regards, pavadrin
  4. C

    Where can I find a list of Christoffel Symbols for Various Metrics?

    Does anyone know where I can find a list of Christoffel Symbols for various metrics? Metrics of general forms, as well as famous ones like Schwarzschild and Robertson-Walker? Yes, I can calculate them all if I really need to, but it's pretty tedious.
  5. Fredrik

    Mathematical statements with logical symbols

    I'd like to get better at writing mathematical statements using logical symbols. Let's start out with something simple. "For every A with property x, there's a B with property y". How should I write that? I don't even know if there's a symbol for "with property". How about this? \forall...
  6. K

    Help with symbols, propto sideways?

    My physics professor used a symbol in his notes that I was unfamiliar with, and so far the closest thing I have found to it is the propto. The only difference is that my prof used it vertically, with the open side up. I'm wondering if this is a different symbol entirely, or if he just tipped it...
  7. Char. Limit

    Exploring Logic Symbols: Meaning of Upside-down A, V, and U

    A lot of times, when I look at something written in logic, there are these strange symbols popping out everywhere. Examples include an upside-down A, a giant V or U, or an upside-down V. Could you point me to an article describing what these symbols mean?
  8. M

    Question about christoffel symbols

    hello, i have a question about christoffel symbols . if we have :- http://www.tobikat.com how can I derive these equations :- [PLAIN][PLAIN]http://www.tobikat.com please i want the answer be clear . with very thanks...
  9. heff001

    Collection of Formulas of Set Theory (Symbols)

    In 'AN INTRODUCTION TO SET THEORY' by Professor William A. R. Weiss, the following symbols are applied to the snippet below: ... The collection of formulas of set theory is defined as follows: 1. An atomic formula is a formula. 2. If ϕ and Ψ are formulas, then (ϕ ^ Ψ) is also a formula. ... I...
  10. D

    Symbols such as derivative symbols

    Can someone help me to put in symbols such as derivative symbols and such? Thanks.
  11. L

    Compute Christoffel Symbols for Metric w/ Time Variable

    I have that g=L^2 \left( e^{-2U} \left( e^{2A} \left( -dt^2 + d \theta^2 \right) + R^2 dy^2 \right) + e^{2U} dx^2 \right) is the metric on my spacetime. taking \{ t, \theta, x , y \} as a coordinate system for the manifol M, i can write this in matrix form as g_{ab}=L^2 \left( \begin...
  12. Monocerotis

    Sixty Symbols [The Greatest YouTube Channel Ever]

    Last week I found wolfram alpha by random chance and it blew my mind, a couple days later I ran across this channel on youtube, and I can't stop watching their videos. I'm officially saying it's the greatest youtube channel ever. You will love it, trust me...
  13. F

    Sphere geodesic and Christoffel Symbols

    Homework Statement I'm trying (on my own) to derive the geodesic for a sphere of radius a using the geodesic equation \ddot{u}^i + \Gamma^i_{jk}\dot{u}^j\dot{u}^k, where \Gamma^i_{jk} are the Christoffel symbols of the second kind, \dot{u} and \ddot{u} are the the first and second...
  14. Q

    Calculating Christoffel Symbols from Metric Tensor

    http://en.wikipedia.org/wiki/Christoffel_symbols#Definition start with 0=\frac{\partial g_{ik}}{\partial x^l}-g_{mk}\Gamma^m_{il}-g_{im}\Gamma^m_{kl} in wiki it said "By permuting the indices, and resumming, one can solve explicitly for the Christoffel symbols as a function of the metric...
  15. M

    Solving Isotopic Symbols Problems: Ar-40 & Beyond

    I am in an online chemistry course and its going well except for this particular type of problems. It states letters and tells me to write what isotope it is. Here goes... Write isotopic symbols of the form X-A (e.g., C-13) for each of the following isotopes. the a isotope with n(subscript...
  16. R

    Proving Epsilon and Covariant Derivatives with Christoffel Symbols

    Homework Statement 1) Show that \epsilon_{ijk,m}=0 and (\sqrt{g})_{,k}=0 . Where ' ,k ' , stands for covariant derivative and \epsilon is the epsilon permutation symbol. 2) where the {} is for christoffel symbol of the second kind. Homework Equations The Attempt at a...
  17. A

    Christoffel Symbols problem in GR

    Homework Statement This is a problem in General Relativity, where I am trying to find the Christoffel symbols that correspond to a given metric. Any help would be greatly appreciated! OK. I have been given the metric ds^2 = (1+gx)^2 dt^2 - dx^2 - dy^2 - dz^2 and have been...
  18. M

    Is There an Easier Way to Set Up Physics Equations Online for Mac Users?

    This may be the wrong place to put this thread, but it appeared to be the best option. Does anyone know of an easier way to set up physics equations online other then finding the keystroke or inserting a symbol? It's a pain to hold ALT on my mac and hit every key trying to find an integral...
  19. W

    Christoffel Symbols for Schwarzschild Metric (?)

    ROUGH DRAFT I have a beginner's basic question: 1. Schwarzschild Metric components Let \epsilon = rs / r, where rs is the Schwarzschild Radius. Then, as is is well-known: g_{00} = 1 - \epsilon g_{11} = - \left( 1 - \epsilon \right)^{-1} g_{22} = - r^{2} g_{33} = - r^{2} \; sin^{2}(\theta)...
  20. H

    Why are there so many different symbols for scientific equations?

    Does anyone have a link or some source for all of the scientific symbols used in equations like this one E=mc2, I know that one doesn't really have any sybols in but I mean like the really long and complicated ones (((THIS IS NOT HOMEWORK!)))
  21. T

    Learn the Meaning of Calculus Symbols | Explanation and Tutorial"

    1. Hi, I am learning calculus off the interenet so that i may learn more advanced physics equations, but sadly I am being held back because i cannot find the meaning of the symbols without the explanation being based around some seemingly random equation like ∫ab x2 dx = b3/3 − a3/3 + blah...
  22. J

    Christoffel symbols etc. via Lagrangian

    I believe there is a way of calculating Christoffel symbols which is easier and less time-consuming than using the metric formula directly. This involves writing down the Lagrangian in a form that just includes the kinetic energy assuming zero potential energy and then equating the coefficient...
  23. T

    Christoffel symbols and Geodesic equations.

    Homework Statement (a) Consider a 2-dimensional manifold M with the following line element ds2=dy2+(1/z2)dz2 For which values of z is this line element well defined. (b) Find the non-vanishing Christoffel symbols (c) Obtain the geodesic equations parameterised by l. (d) Solve...
  24. G

    Definition of uniform convergence written as math symbols

    Hi, how would I write out the definition of "uniform convergence" of a function f(x,y) with as few a possible words and using symbols like \forall?
  25. I

    What is the name of this symbols. See Attachment.

    What is the name of this symbols. See Attachment.
  26. K

    Are Christoffel Symbols Considered Tensors?

    I'm sort of confused about Christofel symbols being called tensors. I thought that to be considered a tensor, the tensor had to obey the standard component transformation law. For example...
  27. M

    Christoffel symbols and tensor analysis

    Hi all! I read about tensor analysis and came about following expressions, where also a questions arose which I cannot explain to me. Perhaps you could help me: I: Consider the following expressions: d\vec v=dc^k e^{(k)} d\vec v=dc^k e_{(k)} where: dc^k=dv^k+v^t\Gamma_{wt}^k dx^w...
  28. N

    LaTeX How to include contraction symbols in LaTeX

    I apologize, I know this is not a QM question per se but I think I am more likely to find someone who could answer this here. I'd like to know (or rather, be reminded of) how to draw contraction symbols in LaTeX (or TeX). I mean the symbol we use to show how two fields are "paired up" when...
  29. F

    Why Hamiltonian and L^2 Don't Commute in Linear Molecules

    Lambda is the quantum number for the total orbital angular momentum of the electrons about the internuclear axis. Unlike in atoms, the cylindrical symmetry created by the strong electric field of the nuclei in a linear molecule destroys the relationship [H ,L^2] = 0. Can anyone tell me...
  30. F

    Atomic & Molecular Symbols: What Do They Mean?

    Atoms have Terms Symbols such as S (L=0), P (L=1), D (L=2), etc...In case of molecules, L no longer exists as other symbols are uesd: which ones?
  31. E

    What do the symbols in quantum equations mean?

    I have a good understanding of general quantum physics but not so much of an understanding of the mathematics around equations, such as the equations on wikipeadia under the quantum physics page to understand any of the equations you much first know what the symbols in the equation means can...
  32. T

    What this symbols means regarding groups

    i got two groups of numbers "a" and "b" what is the meaning of a\b and b\a ??
  33. D

    Symbols Used by Mathematicians - What is a Vertical Bar with an Arrow?

    What symbol is a small vertical bar with an arrow? I know a plain arrow is "determines". Is there a good site that lists the vocabulary of mathematicians?
  34. L

    Sigma Sub/Sup i,j: Differences & Help

    What's the difference between sigma sub i,j and sigma sup i,j??thanks.
  35. T

    Symbols on Div/Curl Question

    Homework Statement Determine Div E and Curl E for each of the following vector fields: \vec{E} = (\hat{x} - \hat{z})cos(3(x - z)) \vec{E} = (\hat{x} + \hat{z})sin(3y) Homework Equations N/A The Attempt at a Solution I can do the div and curl, but I am uncertain what...
  36. S

    Christoffel Symbols: Exploring the First and Second Kinds

    Hi guys, I'm studying C. symbols for my G.R. class and have some doubts I hope you can clear out. First, I just saw this in the wikipedia article for C.s.: 0 = gik;l= gik;l - gmk \Gammamil - gim \Gammamkl By permuting the indices, and resumming, one can solve explicitly for the Christoffel...
  37. F

    Invariant divergence and christoffel symbols

    Homework Statement show that the definition of the invariant divergence divA = 1/√g ∂i (√g Ai) is equivalent to the other invariant definition divA = Ai;i Ai;k = ∂Ai/∂xk + ГiklAl Гkij = gkl/2 (∂gil/∂xj+∂glj/∂xi-∂gij/∂xl) Homework Equations g is the metric tensor...
  38. Tweek

    Need help with physics symbols in question

    Homework Statement I'm taking an online physics course and I do not understand what the symbols mean in the question. The question is: Which of the following is a shorthand way of stating that "the temperature change of a substance is directly propertional to the quantity of heat added"...
  39. A

    Where's the link to the symbols

    so i can write the symbols correctly instead of saying x^2/(4 theta *pi) i can learn how to type them in so you guys can undestand me a lot better
  40. C

    Proving Equations for Positive Integers and Rational Numbers

    Homework Statement Prove uppsidxe Ax, (x is an element Z^+ arrow backwords Ey, backwords Ez, ((y is an element of Q)^(Z is an element of Q)^(yz is not equal to 0)^(x^2=y^2+z^2) Homework Equations The Attempt at a Solution Could someone first help me put this into words? Is it...
  41. Repetit

    Why Do Different Terms Arising From An Electron Configuration Differ In Energy?

    Can someone explain to me why different terms arising from a particular electron configuration have different energies? For example, for carbon in the configuration 1s^22s^22p^2 three terms arise, 3P 1D and 1S. These three terms have different energies but I don't understand why. The electron...
  42. tiny-tim

    Typing math symbols with the alt key on Mac

    ß ∂ ∆ µ π ∏ ∑ Ω … √ ∫ ≤ ≥ ≠ ± # I have a Mac, and I have been typing symbols like the above by using the alt key, and wondering why other people don't use the alt key. :confused: As a result of an in-thread discussion with mkbh_10, and of looking at wikipedia, it now seems that PC keyboards...
  43. S

    Problem displaying math symbols

    Anybody know how I can get my windows XP to display all math symbols? Sometimes instead of the correct symbol, my screen displays a small box. Thanks
  44. J

    LaTeX Welcome to the Forum Latex Symbols Demystified

    Hi everyone I am a new member of this forum and I wonder how can I use those Latex codes for mathematical slymbol displays? I try typing those codes but it came out just the way I type them, do i need to install something before I can use those codes?
  45. G

    Writing Symbols for Elements: A Guide to Chlorine & More

    What is the proper way for me to write symbols for elements such as Chlorine?
  46. S

    Finding Symbols in Microsoft Word Equation Editor

    Homework Statement i have to write on microsoft word the symbol 'N' for natural number and C for complex number but i can't find the symbol on the equation editor Homework Equations The Attempt at a Solution
  47. I

    What are the fundamental symbols and concepts in logic?

    what are the fundamental symbols in logic? maybe this is a vague question but that's cause i don't know anything about logic. are they \neg \wedge \vee? do we define the material implication in terms of these symbols? basically I'm having trouble understanding the paradoxical nature of...
  48. I

    Number Theory (Legendre symbols, quadratic residues/nonresidues)

    Homework Statement "Tell whether the statement is true and give a counterexample if it is false" "Let m > 0 and (m, ab) = 1. If neither x^2 congruent to a (mod m) nor y^2 congruent to b (mod m) is solvable, then z^2 congruent to ab (mod m) is solveable. Homework Equations Legendre...
  49. R

    Using symbols to express my problem here

    Actually I am having a problem with inserting the symbols here. For example if I need to insert the greek letter beta I have to ensert : [\beta but what is " tex" ?
  50. N

    Christoffel Symbols: Solving GR Homework | Fred

    Hey Guys, I'm new here on the forum, and I hope someone can help me out. I'm solving one of my GR homework exercises and I'm asked to find the christoffel symbols corresponding to cylindrical coordinates. I'll post my work and please correct if you see mistakes. I found the metric to be dR^2 +...
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