Recent content by linford86

  1. L

    Magnetic Quadrupole: Model & Vector Potential

    Homework Statement By analogy with an electric quadrupole, one can devise a simple model for a magnetic quadrupole that consists of two small parallel loops with currents circulating in opposite senses and that are separated by a small distance. Consider two magnetic dipoles of equal dipole...
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    Combining Contour Plots in Gnuplot

    I'm trying to combine several contour plots together onto the same graph in gnuplot. I know that I can just do something along the lines of splot "file1.dat" u 1:2:3 w lines, "file2.dat" u 1:2:3 w lines set contour base set no surface set view 0,0 However, when I do that, the data from...
  3. L

    Meaning and derivation of probability

    I agree with lotm. This is, philosophically speaking, a controversial subject area. However, the orthodox mathematical theory -- and, indeed, the one I know best -- is that described by the Kolmogorov axioms.
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    Understanding Lie Derivatives: Acting on Vectors & Tensors

    Sorry it's taken me a while to respond. I've been pretty busy with grad school. At any rate, we want to define something like: L_V T=[V,T] or L_V T=VT-TV for all tensors T and any vector V where L is the lie differential operator. Now, ordinarily, the lie derivative acting on a tensor is...
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    Understanding Lie Derivatives: Acting on Vectors & Tensors

    I did, but I did so by defining a new commutator. Turns out that you actually can do all lie derivatives as commutators so long as you properly define what it means for a tensor to act on a vector (I proved this and, if people are interested, I can post something more explicit later.) After you...
  6. L

    Non-linear Differential Equations and Psuedo-randomness

    Yes, I'm aware of the related Millenium Problem. At any rate, does anyone have any information connecting ergodicity and psuedo-randomness for other systems? That seems intriguing to me.
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    Non-linear Differential Equations and Psuedo-randomness

    Interesting. Do you have any examples? I'd like to know more about this subject.
  8. L

    Understanding Lie Derivatives: Acting on Vectors & Tensors

    Thanks for your reply! Can you give an example of either of these methods?
  9. L

    Understanding Lie Derivatives: Acting on Vectors & Tensors

    I've been trying to get a grasp on Lie Derivatives. I understand that we can represent a lie derivative acting on a vector as a commutator. What do I do when I act a lie derivative on a tensor? Can I still just write out the commutator?
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    Non-linear Differential Equations and Psuedo-randomness

    I was thinking about the non-linear Navier-Stokes equation this morning and was briefly browsing a text on the subject. I'm aware that one popular approach to dealing with turbulence is to take averages and look at correlators (which, in turn, can be related to field theory.) Now, one thing...
  11. L

    Efficiency of Carnot Engine Question

    Ha, that's so obvious! Thanks! How do I mark this thread as "Solved"? I tried looking under "Thread Tools" but I didn't see an option for doing that...
  12. L

    Efficiency of Carnot Engine Question

    Homework Statement This is from "Equilibrium Statistical Physics" by Plischke and Bergerson, problem 1.1: "Consider a Carnot engine working between reservoirs at temperatures T1 and T2. The working substance is an ideal gas obeying the equation of state [ PV=Nk_BT ], which may be taken to be...
  13. L

    Labview/DAQ Problem: Accelerometer Measurement Troubleshooting

    I actually solved this problem today. The connector from the external circuitry to the DAQ on the back of the computer wasn't tight enough, so the ground wasn't actually being properly connected. Why the signal saturates when there's nothing connected beats the hell out of me. At any rate...
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    Labview/DAQ Problem: Accelerometer Measurement Troubleshooting

    I'm trying to use an accelerometer to take measurements. I have it physically wired to my computer's DAQ board (a NI 6025E). According to the manual, pin 1 is ground and pin 3 is analog input 0. Therefore, this is where I have the output from my accelerometer going. I checked the signal at those...
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