Physical Definition and 1000 Threads

  1. S

    Oleum Fuming: Investigating the Physical Mechanism

    I'd like to know the physical mechanism of oleum "fuming" on its surface. Dissolved SO3 reacts very exothermically with some air humidity. Why does the mist occur instead of dissolving created H2SO4 in the solution?
  2. cseil

    Local and integral physical quantities

    Hello everyone, I'd like to know if my understanding of local and integral quantities is clear. An integral quantity refers to the entire physical system, it is not defined point by point. A local one is defined point by point, for example ρ(x,y,z). Can I consider the charge dq as a local...
  3. A

    Physical meaning of max. proper distance at time of emisson

    I cannot picture the physical meaning of the maximum proper distance at time of emisson. In the benchmark comological model the plot of (H/c) * (Proper distance at time of emission) versus z (the redshift) shows a maximum at z=1.6 for a proper distance of emission = 1800 Mpc (mega parsecs). I...
  4. D

    Does Resonating an Inductor at Its Physical Frequency Improve Efficiency?

    17:47 - dlbeeson: Is there any benefit of setting capacitance of an LC tank to resonate an inductor at its natural physical resonance frequency, like a tuning fork frequency? Like a brass pipe hanging on a string in a wind chime, the inductor must also have some physical resonating frequency...
  5. Anique

    Are These Dimensions of Physical Quantities Correct?

    Hello there, I have a confusion between dimensions and units! All of others tell me its not unit but some use units! Please verify the following Quantity Dimension Length L Mass M Time T Temperature Θ Amount of...
  6. kelvin490

    Physical significance of temperature

    Some books say when heat flows into a monatomic gas at constant volume, all of the added energy goes into an increase in random translational molecular kinetic energy. But when the temperature is increased by the same amount in a diatomic or polyatomic gas, additional heat is needed to supply...
  7. N

    Physical interpretation of divergence

    I'm trying to figure out what the physical meaning of divergence is for a vector field. My textbook offered the following example: if v = <u, v, w> represents the velocity field of a fluid flow, then div(v) evaluated at P = (x, y, z) represents the net rate of the change of mass of the fluid...
  8. L

    Why isn't solution state a true physical state ?

    why isn't solution state a true physical state but a pseudo state?
  9. D

    Motherboard bus speed physical maximum

    I read somewhere (article, messageboard, i can't find it anymore) that motherboard bus speeds are limited because if the frequency gets too high then the signal will disappear. I guess I understood it to mean that the bus wire will become like and antenna if the frequency is too high. They...
  10. J

    Physical Chemistry pH question

    Homework Statement The dissociation constant Ka for the acid-base reaction HA-->(H+)+(A-) is given by Ka = products / reactants; but instead of listing Ka, people generally list pKa = -logKa (where log indicates the 10-base logarithm). Similarly, instead of using [H+], people generally use pH...
  11. Lamdbaenergy

    What Happens If We Change Just One Physical Constant?

    So, I know that there are already three absolutely mandatory physical constants, like the gravitational constant, the Planck constant, and the speed of light. But what if you only changed the value of one constant? For example, if you changed the value of the gravitational constant to 4.4663 x...
  12. B

    Dimensional analysis of a physical pendulum

    Hi! Sorry if this is the wrong section to post this: I am doing a laboration on physical pendulums and I have a bit of trouble making sense of it all and I am in need of some guidance. When I do the analysis I get the standard mathematical pendulum. [T]=[m]^a*[l]^b*[g]^c, where a = 0, b = -c...
  13. M

    Understanding the physical meaning of phase shift in underdamped systems

    Hello all I know that the step response of a second order underdamped system is : y(t) = 1 – (e^(-ζωn*t) / sin(θ))*sin(ωd*t + θ) Where sin(θ)= sqrt(1-ζ^2) , ωd = sqrt(ωn^2 – ωn^2 * ζ^2 ) my question is: I can see on the simulation ωd and I can calculate it , but I want also to see the...
  14. S

    Physical interpretation of the stress energy momentum tensor

    First, I'd like to thank everyone that has helped me thus far in deriving the general relativistic tensors for the Morris-Thorne wormhole metric in an orthonormal basis. I have finally done it and grasped that concept. Now that I have done that, my new stress energy momentum tensor for this...
  15. W

    Investing in Stock Markets: Fat Tails, Persistence, Multifractals & Turbulence

    Does anyone here know much about these topics? I understand they surround the absence of normally distrubted returns, excessive kurtosis. Fat tails somehow disprove the EMH? Can anyone explain this argument? I've been advised that there are links to turbulence in fluid dynamics, joined by the...
  16. J

    Physical Chemistry: Chemical Equlibrium

    Homework Statement For the reaction: 2SO3(g) →2SO2(g)+O2(g) when 2.00 mol of SO3 is added to a flask at 10.0 L and 350 K at fixed volume, at equilibrium the ratio of SO2:SO3 is 0.663. What is the values of the equilibrium constant? What is ΔG° at this temperature? Homework Equations...
  17. P

    Physical meaning of orbital polarization?

    In this paper, the Orbital Polarization (OP) is defined as: $$OP=\frac{n_{x^2-y^2}-n_{z^2}}{n_{x^2-y^2}+n_{z^2}}$$ where $$n_i$$ is the occupancy of that given orbital. I would like to understand the physical meaning of this. Also, is there a difference between OP and Orbital Hybridization?
  18. vlemon265

    What is the physical unit for teleport?

    We use ms-1 for unit of speed. But what is the physical unit for teleporting a mass to a distance L? Is it also [L]/[time]? But it seems it does not take time for teleport. I am seeking help. Thanks very much.
  19. vlemon265

    What is the physical unit of teleport?

    We use ms-1 for unit of speed. But what is the physical unit for teleporting a mass to a distance L? Is it also [L]/[time]? But it seems it does not take time for teleport. Seeking help. Thanks p.s: my reference http://www.nature.com/nature/journal/v488/n7410/full/nature11332.html
  20. G

    Physical interpretation of Force=power/velocity

    I understand the derivation of the equation Force=power/velocity, but I'm not sure I quite understand the physical interpretation of this. If you had a constant force acting on a particle in a vacuum, then it would gain velocity and as it did so the power would have to go down for the force to...
  21. 1

    Enthelpy's physical interpretation

    Hi I'm new to this site, so I'm not sure where to post this question but chemistry seemed fitting. I'm current taking 2 thermo classes, engineering and chemistry, and I'm having trouble with the concept of enthalpy. This is what I believe I understand. I Hope the following is all correct if...
  22. J

    Partial Derivative Manipulation for Physical Chemistry Homework problem

    Homework Statement Given the functions Q(v,w) and R(v,w) [/B] K = v(dQ/dv)r and L = v(dQ/dv)w Show that (1/v)K = (1/v)L + (dQ/dw)v (dW/dv)r I have the problem attached if for clarity of the information. Homework Equations I assume everything is given in the problem. The Attempt at...
  23. I

    Physical infinities, what are the limitations?

    From a mathematical point of view there can and is many different infinities that exist. I'm curious what happens when we try to use a physical infinity in cosmology. I'm not going to lie I don't even think my brain is capable of comprehending this but can two physical infinities exist...
  24. P

    Physical Pendulum Formula Derivation

    Homework Statement A physical pendulum, consisting of a uniform rod (of mass M and length L) with an attached blob, can oscillate about an axis that goes through one end of the rod. The mass of the blob is also M. The distance of the blob to the rotation axis is x. The aim is to derive a...
  25. C

    Calculus intuitive and physical approach - me understand.

    Hi if i have a function that relates time and distance travelled, is this correctly understood: (please tell me what is correct and what is wrong - it would help me understand) The function is f(t)=16(t^2) 1. f(4) = 256 This tells me that at the END of 4 seconds (or is it at the...
  26. S

    Can Physical Laws Be Truly Independent?

    There is a famous example that electron couldn't absorb the whole incoming photon without emitting another one. Instead of the normal way, I try to prove it simply by argument ( which might be wrong ). There are four constraints in the process, one from energy conservation, three from momentum...
  27. ChrisVer

    Wavefunction real physical object?

    Here : http://en.wikipedia.org/wiki/Penrose_interpretation One reads: I wouldn't be a liar to say that I understood almost nothing about this...what's the formulation behind it? First of all, how can the wf be a physical wave? it corresponds to what? Also I find obscure the use of...
  28. M

    Physical Interpretation of Coordinates in GR

    What is the relationship between the differentiable manifold that is space-time and the physical space around us? How does one relate the three seemingly Cartesian coordinates around us, those which we can measure out with a ruler, to the coordinates of the Lorentzian manifold? If i say, measure...
  29. ShayanJ

    Physical reason vs. Mathematical reason

    Sometimes people ask a question and when I answer them in terms of equations, they say they want the physical reason, the real reason.. 1- Do you think there is a distinction between physical and mathematical reasons? 2- If your answer to the last question was yes, explain the distinction! if...
  30. Telemachus

    Continuum mechanics, physical interpretation of terms in balance eq.

    Hi there. I'm reading Gurtin's 'the mechanics and thermodynamics of continua', and working some exercises of his book. In the section 21: 'The first law: balance of energy', after the derivation of the balance equation, he uses an identity to rewrite the balance of energy. The balance of energy...
  31. AbhiFromXtraZ

    Physical Meaning Of Divergence

    Currently I'm reading Magnetostatics. While reading Divergence of B, I fell into a confusion that what divergence really means w.r.t. a coordinate system. Supposed there is a current distribution J at r' w.r.t. some primed coordinate system. And B is defined at position r w.r.t. unprimed...
  32. L

    Time as a Derived Physical Quantity

    Time as a Derived Physical Quantity Consider a physical system whose state changes and let us call it a Dynamical System. Let a closed Dynamical System, S, whose state be described by ψ-- A mathematical entity we use to describe S (or the state of S). ψ can take on the following...
  33. R

    Modes - physical meaning and use

    Modes is usually encountered in physics when we study wave propagation of any sort. Every frequency has n number of modes depending on boundary conditions - I know that much but, find it difficult to relate to so many concepts in which modes get mentioned and they baffle me at times. I want to...
  34. 1

    Orthogonality and physical applications

    Just as we have orthogonal vectors/vector spaces/etc., we can have orthogonal functions/function spaces/etc. I'm trying to apply these concepts to physical processes. Here's a general idea of what I'm doing: Suppose you have a physical quantity you are trying to measure, ##F##, and it depends...
  35. Jonathan Scott

    Entanglement and physical spacelike connection

    One theory I've heard and which I find interesting is that entanglement between any pair of two-state systems could be explained deterministically by a spacelike connection which can only communicate something relative, like a phase difference, and which is essentially holding the ends...
  36. RUTA

    The physical world cannot be a single history

    Here is a fun talk by Fay Dowker on a path integral approach to the Greenberger-Horne-Zeilinger (GHZ) correlations. It's a physical instantiation of N. David Mermin's "no instruction sets" for GHZ in his Am. J. Phys. paper "Quantum mysteries revisited," v58, Aug 1990, 731-734. The talk...
  37. Radarithm

    Does the action have any physical significance?

    After studying the methods of Lagrange and Hamilton for a bit I still find myself uneasy about the action. I don't even know how to define it other than the integral of the Lagrangian with respect to time: $$I=\int_{t_1}^{t_2}\mathrm{d}t\, L(q,\dot{q},t)$$ Does the action have any...
  38. HakimPhilo

    What's the physical interpretation of ##\mu_0## and ##\varepsilon_0##?

    What are the physical interpretations of ##\mu_0## and ##\varepsilon_0##, the magnetic permeability and electric permittivity of vacuum? Can these be directly measured? How?
  39. N

    Physical reasons for having a metric-compatible affine connection?

    So as the title says, what are the physical reasons behind requiring the connection between tangent vector spaces to be metric-compatible? My guess is that this is desired from wanting different points in space-time to be "equivalent", in the sense that if any two vectors at a point are the...
  40. C

    Physical explanation for power broadening

    I have been looking into broadening mechanisms and I'm stuck at trying to provide a physical explanation for power broadening. I get how the math shows that at high intenseties the decay rate goes through the roof due to saturation, but how does this increased decay rate manifest in a spread of...
  41. B

    Physical Interpretation of a Vector Quantity

    Homework Statement If \mathbf{r}, \mathbf{v},\mathbf{a} denote the position, velocity, and acceleration of a particle, prove that \frac{d}{dt} [\mathbf{a} \cdot (\mathbf{v} \times \mathbf{r})] = \dot{ \mathbf{a}} \cdot (\mathbf{v} \times \mathbf{r})Homework Equations The Attempt at a Solution...
  42. ChrisVer

    Views on Answering Physical Questions

    Well generally it has come to my attention that a lot of people answer to some questions with the comment: "well, that's like saying that if the laws of physics are like X" -X the false statement- "then Y is true" -Y false conclusion. Well that's not really enlightening I think. The main...
  43. D

    How can I protect my bandaged ankle while showering?

    I have a sprained ankle. On my first visit to the therapist, he stuck a bandage on my ankle, such that it went 270deg around. Issues: 1. No mention of how I am supposed to shower. Do I take care to leave the bandage or do I let it peel off? I take a shower everyday, and there is no way the...
  44. W

    Mathematical and physical concepts in nanoscience

    Dear all, I am going to attend masters program in micro and nano technology. I would like to know what concepts of maths and physics I should be clear at and some good textbooks for the same. My study module includes nanoscience, nanomaterials and nano electronic design.
  45. C

    Did Einstein have a Physical Interpretation of Frames?

    By a frame I mean four orthogonal vectors for which one is timelike and the others are spacelike. In a bypassing some time ago I read something about the basis vectors in a frame representing sticks and and a clock. However, the author also noted that this interpretation was problematic. I...
  46. C

    Difference between physical property and physical quantity?

    Difference between physical property and physical quantity?? Hi I'm confused after reading the definitions of physical Quantity and physical property: Definition from wikipedia: physical quantity= is a physical property of a phenomenon, body or substance that can be quantified by...
  47. T

    Should objects that are connected share the same physical laws?

    Hi, Consider the various kinds of objects we have in our universe, from the smallest to the largest - sub-atomic particles, atoms, molecules, single-celled organism, multi-celled organisms, cities, countries, planets, stars, solar systems, galaxies, collection of galaxies, universe. Since...
  48. J

    Bel is unit for what physical quantity?

    If Newton is unit for measure force, meter is unit for measure length and radian is unit for measure angle, so, bel is unit for measure which physical(/mathematical) quantity?
  49. H

    Physical meaning of solution to step potential with E = V0

    I am able calculate the solution for the TISE relating to the interval to the right of a step potential; however, I am unclear as to what this solutions represents physically for this scattering problem. So, starting with (-ħ2/2m)d2/dx2Ψ2(x) + V(x)Ψ(x)2 = EΨ(x)2 where V(x)Ψ(x)2 =...
  50. B

    Physical Interpretation of EM Field Lagrangian

    Using differential forms and their picture interpretations, I wonder if it's possible to give a nice geometric & physical motivation for the form of the Electromagnetic Lagrangian density? The Lagrangian for the electromagnetic field without current sources in terms of differential forms is F...
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