Measure Definition and 1000 Threads

  1. J

    How to measure the transfer function in Simulink?

    Let's say I simulate a simple filter in simulink and I want to see the transfer function graph (bode plot) of it. What do I do to get Vout/ Vin? I tried using the "PS Divide" Block and divide the output voltage and the input voltage, but that didn't work. Could anyone help me out here? This...
  2. S

    How does one measure the absolute velocity of an object?

    It is well-known that the velocity of an object can only be determined in relation to the velocity of another object (the two trains in a station). Einstein's relativity theory limits the velocity of an object to the speed of light; it also been demonstrated that no matter what the velocity of...
  3. Artlav

    How to measure a capacitance of an isolated object?

    How can you measure a capacitance of an isolated object, like a conductive sphere or a coil? Can it be done using a typical RLC meter? I've tried touching only one end of the probe to the object in question, and that seems to give sporadic readings, but within the order of magnitude of the...
  4. B

    Thermodynamics-Gibbs free energy: what can we actually measure in the lab?

    Thermodynamics--Gibbs free energy: what can we actually measure in the lab? Hi everyone: I am getting back into thermodynamics after a long absence and have realized that there are basics I have never understood. If a patient person could either explain or direct me to an online resource...
  5. A

    Measuring Power in Simple Circuits

    In a simple circuit with a power source, electric conductors and a load, you can measure the power being dissipated by measuring the voltage across the load and multiplying by the current. If you only have access to one conductor, for example, an electrical distribution cable, how can you...
  6. N

    Peskin & Schroeder p. 285, change of variables integration measure

    I had a question about about the integration measure for the path integral after a unitary change of variables. First they consider a 4D spacetime lattice with volume L^4. The measure is \mathcal{D}\phi = \prod_i d\phi(x_i) They expand the field variables in a Fourier series...
  7. N

    Exploring the Cut-Back Method: How to Measure Propagation Losses

    How does the Cut-Back method work experimentally? The Cut-Back Method is a method to determine the propagation losses of fibers or waveguides. I have found tons of articles stating they used this method in comparison but no detailed information on how one can execute it successfully...
  8. R

    Interpreting path integral averages as measure integrals

    Hi all, Sorry if this is in the wrong place. I'm trying to understand probability theory a bit more rigorously and so am coming up against things like lebesgue integration and measure theory etc and have a couple of points I haven't quite got my head around. So starting from the basics...
  9. B

    Measure of the Sharpness of a curve

    Measure of the "Sharpness of a curve" I have a set of curves that belong to the family of curves y=\frac{c}{x^m}, where m and c are parameters. The attached picture (save.png) shows three such curves for different values of m and c. Now these curves have different 'sharpenss' of curvature (to...
  10. K

    How do you measure how strong a spring is?

    Homework Statement So I have before me a set of springs about this size: http://tinyurl.com/8g7kvu5 . Some are a little longer, some are wider, and some are slightly stronger. I need a home-made way to measure how much potential energy each spring can build up if I compress it at 2 inches or 3...
  11. F

    Basic random variable question - measure theory approach

    I have always struggled in understanding probability theory, but since coming across the measure theoretic approach it seems so much simpler to grasp. I want to verify I have a couple basic things.So say we have a set χ. Together with a σ-algebra κ on χ, we can call (χ,κ) a measurable space...
  12. D

    Lebesgue outer measure of a set of countably many points is 0 - logic check

    So I know that the Lebesgue outer measure of a set of only countably many points is 0. An example of this is the rationals as a subset of the reals.I want to make sure my intuition behind this is correct. The process: Now, if we are going to take the Lebesgue outer measure of the rationals, we...
  13. B

    How can I accurately measure RF impedance on a wire with a glass coating?

    I'm trying to determine the best method of measuring impedance from a wire through it's glass coating to determine if the thickness of the coating is correct. At the moment I do not have the actual frequency, I just know it is in the RF range and that my impedance needs to be 50 ohms. I've...
  14. R

    Measure big biulding resistance with Earth tester

    HI ALL We have a big building.there is a ring around the building as earthing system. we put bare cooper wire in trench around building . NOW,we are going to measure the resistance of earthing system with Earth tester. Our device is MI 2124 ,one production of METREL . how I can...
  15. J

    A measure related with Reimann integral

    Homework Statement Let ( \mathbb{R}^k , \mathcal{A} , m_{k} ) be a Lebesgue measurable space, i.e., m_{k}=m is a Lebesgue measure. Let f: \mathbb{R^k} \to \mathbb{R} be a m-integrable function. Define a function \mu : \mathcal{A} \to [0,\infty] by $$ \mu(A) := \int_{A} f(x) dx $$ with A \in...
  16. M

    Why do different gauss meters measure magnetic field strength differently

    I have used two different Gauss meters to measure the same NdFeB rare Earth N45 (45 MGOe) disc magnet (D28X6mm), with a Residual Induction (Br) of 1320-1380 mT. The first is a Dr. Steingroever GmbH FH51 Gauss meter. It would take readings of up to approximately 1.2 Tesla (12,000 Gauss)...
  17. I

    How to measure copper sulfate specific heat

    Homework Statement I was wondering, how can i measure the specific heat capacity of a solution? Not the exercise, just doing an experimental work to measure it. Homework Equations q=mct The Attempt at a Solution I'm lost.
  18. P

    Can we Measure and Quantifying smell? (Dog Experiment)

    So right now I am shadowing a 8th grade science teacher at Drew Charter school and I was helping a student work on his idea come up with a science fair project. The student wants to study what kind of smells do dog's prefer over other's but using household (safe items), food, and dirty...
  19. C

    How do we measure time more accurately?

    So I'm beginning to study photonics and the issue of excessively accurate reference times for clock signals are mentioned. I understand that natural frequencies are often compared to determine the accuracy of a time measure (olden times it was vs astronomical events and nowadays it's against...
  20. T

    How do we measure the position of a particle?

    I'd like to know with some precision how the position of a particle is measured. Just to focus the potential answers, I'd like to know some details of it because perhaps with that I could get a better understanding of some basic principles such us: 1) commutation relation of x and p 2) some...
  21. E

    How to measure center-to-center or centre-to-centre?

    I've always been confused by this concept: How do you measure center-to-center in engineering terms when the objects are on different x and y coords? When objects cross the same x or y plane it's simple enough, just draw a straight line from center to center. When they aren't on the same x or y...
  22. M

    Medical Which is the principle and technology that enables us to measure objectively myopia?

    hello! which is the principle and technology that enables us to measure objectively myopia, astigmatism and presbyopia? thanks!
  23. H

    What is/how do i measure the module of these bevel gears?

    Hi all, I've got 2 bevel gears that I'm recreating in CAD, I've got the shapes down it's just a little bit of fine tuning with the dimensions, for which I need the module/diametral pitch of the gears. The pinion has 9 teeth and a tip diameter of roughly 39.3mm, and the gear has 14 teeth and a...
  24. P

    Planck's constant as a measure of significance

    The basic concepts used in physics are mostly derived from everyday human experience. Hardly surprising for a subject which usefully describes our contingent physical circumstances. For example dynamics involves ordinary and familiar concepts like mass, and changing distance is described as...
  25. C

    Justin T. Moore: Why Every Size \aleph_1 Has Measure Zero

    I have attached part of 2 pages from Justin T. Moores dissertation. I am wondering why he says every set of size \aleph_1 has measure zero. He is probably using some axioms that i am not familiar with. And I am not sure what the k_2 is. He says this towards the bottom of the...
  26. D

    New unbiased technique for the measure of the local dark matter density

    Plenty of Dark Matter Near the Sun http://www.sciencedaily.com/releases/2012/08/120809090423.htm Evidence for dark matter near the sun "We are 99% confident that there is dark matter near the Sun," says the lead author Silvia Garbari. In fact, if anything, the authors' favored dark...
  27. R

    Will we measure the velocity c?

    I had an experiment in my mind and I wonder if anyone could help me out with this, I'm just familiar with the basic concepts of relativity so all help is appreciated. Imagine the following case below in the image I have posted (it's possible this image will be gone as time moves forward)...
  28. C

    Why Do We Use Light Signals to Measure Time?

    why do we use light signals to measure time? In flat spacetime Let's say we have two observers in one's rest frame the other one has velocity v. We suppose each of them sent light signals to other one with time separation of Δt(their proper time) and measure time accordingly.we see time...
  29. S

    How Can We Quantify Homogeneity in Physical Systems?

    We all know what it means to be homogeneous in a "hand waving" sort of way. And, of course, there are abstract mathematical definitions for a homogeneous space. I have been unable to find a physical measure of homogeneity which could be applied to a ensemble of particles, box of rocks, or the...
  30. B

    What is the Haar Measure on SO(4) and Where Can I Find References?

    I wasn't quite sure where to post this question, so please forgive me if I chose the wrong place. Essentially I'm looking for an explicit expression for the Haar measure on SO(4), i.e. in terms of angles, or if you prefer, expressed in terms of the Lebesgue integral over a subset of the Lie...
  31. S

    Measure Phase velocity/group velocity of EM-wave

    Hey folks, some weeks ago we had an trial-exam and one of the questions there was: "How do you measure phase and group velocity." That question really got me. Having a fastly oscillating wave as carrier and then the envelope. Can someone help me? Is it impossible for the phase, as it is...
  32. O

    Understanding Measure Theory with Rudin's Principles of Mathematical Analysis

    Hello everyone, I needed to know more about measure theory so I'm reading in Rudin's Principle's of Mathematical Analysis, somewhere in the chapter, he says: We let E denote the family of all elementary subsets of $R^p$... E is a ring, but not a $\sigma$-ring. According to my understanding of...
  33. F

    Measuring Momentum: Is One Measurement Enough?

    I realize that this would probably be patently obvious if I understood the nature of particles, but how is it possible to measure the momentum of a particle with just one measurement? Doesn't determining velocity require multiple measurements?
  34. P

    Is Mass the True Measure of Inertia?

    You have cement block placed on Earth and moon with same mass. When you try to push the block it would be easier to push the block on moon than on Earth i.e. the inertial property shown by block on Earth is more than it shows on moon. But the mass is same on Earth and moon. When you have inertia...
  35. M

    Can Tube Diameters Be Measured Internally with Waves?

    hello! lets say we have a long tube with variable diameter and with variable direction is it possible to measure the diameter of its walls in each point of its lenght, by sending waves or something from its edge towards inside it ? imagine it is not possible to access the outside of the...
  36. S

    Measure the speed of earth in universe

    suppose an electrostatic sphere and an very sensitive magnetometer are placed in a space that has magnetic field outside been screened ideally. Can we know the speed of the Earth transverse in the universe by dealing with the data obtained?
  37. K

    How to measure noise from a current source

    I'm asked to get the noise signal from the constant current source I built with a 741 Op-Amp. I know I have to read it from the scope, but how do I go about the connections to the scope, and what other procedures must I follow to read the noise contribution? Pls refer to the figure provided in...
  38. T

    How to measure force due to a tidal wave?

    I was thinking about (for experience, since somebody's probably already done it) making a sort of generator, with the shaft of the turbine connected to four perpendicular flat pieces. In water, waves would smash against the pieces, rotating the shaft and hopefully generating electricity. The...
  39. azizlwl

    The WMAP objective is to measure the temperature differences in the

    The WMAP objective is to measure the temperature differences in the Cosmic Microwave Background (CMB) radiation. My question are, 1.How to distinguish all the radiations of 13 billion years ago from others of the latter ones. 2.How the distance of radiation source is measured. Thanks.
  40. O

    Measure of Relativistic Flattening of Electric Field

    Homework Statement As a rough measure of the relativistic "flattening" of the configuration of electric field lines from a moving charge, we might use the angle \alpha between two conical surfaces which include between them half the total electric flux. That is, half the flux through a sphere...
  41. A

    Methods used to measure the density of solid materials and liquids.

    Homework Statement I have to find two methods used to measure the density of a solid material and one method to measure a liquids density Homework Equations n/a The Attempt at a Solution got one method for the solids and have written this but my teacher wants me to find the...
  42. Steve Zissou

    Unit of Measure of Exponentiated Item

    Hello. Let's say we have the quantity f=1/(1+x) where x has no unit of measure. What is the unit of measure of f, once we take f^t, where t can be in years? Thanks
  43. F

    How to measure the filter roll-off rate

    Hello, I have taken the attached filter response graph of filter gain to frequency created in micro-Cap. My cutoff frequency is 1kHz. How can I measure the roll off rate in db/Dec based on this graph ? Perhaps there is a formula ? Any help would be appreciated.
  44. R

    By what equation do physicists use to measure the time before the CMB

    I'm reasonably convinced that physicists know what happened in the universe at certain temperatures: just find out what happens when you reach those temperatures in a particle accelerator. I still have yet to come across the equation that measures the time before the CMB and what the universe's...
  45. P

    Induced Measure: Understanding the Concept

    What is an induced measure? I have seen the formal definition many times i am trying to get a grasp of this concept. Does an induced measure mean that we can view the measure associated with a random variable as some co-ordinate function defined on R? Is it the cdf?
  46. T

    Is independence indpendent on measure?

    Is it possible that 2 sigma-algebras could be independent under one measure but not independent under another? Many thanks.
  47. G

    Time Dilation: Why Do Observers Measure Different Times?

    hi i have some troubles to understand something properly: if oberserver A is not moving in his inertial frame and there is some observer B moving relatively to oberserver A with velocity V, then this observer B will measure a different(shorter) time from the one that is measured by observer A...
  48. R

    How to Measure the Bandwidth of an LNA?

    My question is two fold. 1) I was asked to measure the BW of a LNA (RF2472G). Is this done with a VNA. I have an obsolete model in my lab Agilent/HP 8720ES. 2) Exactly how would you measure the BW of the LNA in general? Using the VNA? Is this a S11, S12, S22, S21 parameter? please help.
  49. W

    Is it related to measure theory - Help

    Hi all, I am not sure that if I have posted this thread on right place but as the subject is related to the stochastic & measure theory therefore I am posting it here. Well, my question is that in the subject "Preferences, Optimal Portfolio Choice, and Equilibrium" the tutor has used the...
  50. W

    Why Isn't A^c the Empty Set in This Measure Theory Example?

    Hi all, I am reading Probability and Measure by Patrick Billingsley, and I am stuck at one example, please help me understanding it. http://desmond.imageshack.us/Himg201/scaled.php?server=201&filename=30935274.jpg&res=landing Ω=(0,1] My question is that how come the A^c = (0,a_1]U(a'_1...
Back
Top