# Thomson Definition and 42 Threads

Thomson Reuters Corporation ( (listen)) is a Canada-based multinational media conglomerate. The company was founded in Toronto, Ontario, Canada, where it is headquartered at 333 Bay Street (Bay Adelaide Centre).Thomson Reuters was created by the Thomson Corporation's purchase of the British company Reuters Group in April 2008 and is majority owned by The Woodbridge Company, a holding company for the Thomson family.

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1. ### I Thomson Scattering -- elastic collisions conundrum

Teacher described the Thomson scattering effect through the lens of the electric field changing as a moving particle is accelerated. The changing electric field of the electron accelerating carries with it an amount of energy, and this energy radiates out from the acceleration event. (there were...
2. ### What is the relationship between entropy and pressure in thermodynamics?

Hi, Starting from dS in term of H and P, I'm trying to find ##(\frac{\partial H}{\partial P})_t## in term of ##P,V,T, \beta, \kappa, c_p##. Here what I did so far. ##ds = (\frac{\partial S}{\partial H})_p dH + (\frac{\partial S}{ \partial P})_H dP## ##ds = (\frac{\partial S}{\partial H})_p [...
3. ### Thomson scattering -- Photons can only scatter from free electrons?

Hello , Why does an incoming photon can only scatter from an electron if the electron is not bound top an atom ? Because from what I know a bound electron can absorb a photon then be excited to a higher energy level and then re-emit a photon while transitioning back to it's previous energy...
4. ### How Does Joule Thomson Expansion Affect Gas Temperature?

Wikipedia says, Unlike a free expansion , in Joule Thomson expansion work is done causing the change in internal energy. Whether the internal energy increases or decreases is determined by whether work is done on or by the fluid; that is determined by the initial and final states of the...
5. ### A De Broglie to Schrödinger to Thomson to Bohm?

I'm investigating some newly conceived Hamiltonians using the approaches of de Broglie and Schrödinger as jumping off points. Lanczos in "The Variational Principles of Mechanics" p. 278 describes and analyzes them. Neither de Broglie nor Schrödinger really completed the program of the H-J...
6. ### B A doubt on Thomson's Experiments to determine the value of e / m_e

By carrying out accurate measurements on the amount of deflections observed by the electrons on the electric field strength or magnetic field strength, Thomson was able to determine the value of e/me as... e/me = 1.75 10^11 C kg^-1 would this be a correct understanding of this para- "This para...
7. ### Solving for a neutralizing B0 in a Thomson Cathode Ray (Algebra?)

I've attached a picture from the problem, the given equations, and my work so far. I knew I had a problem when My units wouldn't check out. This should just be simple algebra but It's not working. Please help me to understand what I am doing wrong.
8. ### Thomson Experement, Derive deltaY between E=0 and E=E0

There are more parts to this problem but I can't get to those until I finish this one. I have attached figure.1 and some my work so far, including my answer which the system rejected. (I had to copy my work from my original sheet as it contained sensitive information I didn't want to upload)...
9. ### Particle Thomson (Modern Particle Physics) & Schwartz (Quantum Field Theory)

Hi. Are these two books complementary, or do they have too much in common? https://www.amazon.com/dp/1107034264/?tag=pfamazon01-20 www.amazon.com/Quantum-Field-Theory-Standard-Model/dp/1107034736/ My problem is that I still don't quite understand the difference between university courses in...
10. ### JJ Thomson Discovery of the Electron

pg. 243 Falconer, I. (1987) Corpuscles, Electrons and Cathode Rays: J.J. Thomson and the Discovery of the Electron. The British Journal for the History of Science (BJHS, 1987,20,241-276). "One of their most important properties is that they are deflected by a magnetic field. This provided strong...
11. ### Electrical Optimal Components for a Thomson Coil?

I'm interested in making a Thompson's Coil after seeing my University's physics II (EM) professor demonstrate Faraday's Law to us using it. It seems like a fun device to demonstrate various principles of Electromagnetism to lay people (Induced Voltage by Faraday's Law, Resistive Heating...
12. ### Joule Heating and the Thomson effect in Drude theory

Homework Statement ##\mathbf A##.Joules heating Consider a metal in a uniform temperature in a static uniform electric field E.An electron experiences a collision, and then after a time t, a second collision. In the drude model , Energy is not conserved for collisions, for the mean speed of an...
13. ### B What Effect Does Opening a Valve in a Vacuum Have on Air Molecules?

Hi Suppose there is a 1 m3 cylinder containing 1.3 kg air at 25 C. The cylinder is sitting in a vacuum place. The air inside the cylinder will exert a pressure of almost 1 atm. The cylinder also has a valve which can be opened to let the air out into surrounding vacuum. The average speed of...
14. ### Thomson Scattering In the Early Universe

Homework Statement Why does Thomson scattering occur in the early universe? Homework Equations $$e^{-} + \gamma \rightarrow e^{-} + \gamma$$ is a Thomson scattering process if: $$E_{\gamma} << m_{e}c^{2}$$ (Electrons are essenitally stationary) The Attempt at a Solution [/B] Very confused...
15. ### Thomson's jumping ring: Why net repulsion?

Hi. According to Lenz's law, a conducting ring responds to an increasing external magnetic field with a repelling field and to a decreasing external magnetic field with an attracting one. Thomson's experiment uses an AC coil, so its field strength changes between increasing and decreasing a...
16. ### Thomson scattering and radiating power

I have a question about Thomson scattering from an electron hit by an incident em plane wave. The derivations that I have found all state the same thing. You have an electron in the origin at rest as the initial condition, the incident plane wave is linearly polarized towards z with amplitude...
17. ### Thomson, Modern Particle Physics, Problem 6.7

In Mark Thomson's Modern Particle Physics, Problem 6.7, I am wondering how we obtain: 2(ms, 0, 0, 0) and -2(ms, 0, 0, 0) for the RL and LR helicities (likewise for the muon) in the electron currents using helicity combinations. My solutions for the other helicities (RR, LL) work out, but I am...
18. ### Thomson and Rutherford's experiments

Homework Statement If Thomson's "plum pudding" model was correct, what could have happened when Rutherford fired high energy alpha particles at gold foil?Select all that are True. Alpha particles are reflected. Alpha particles pass right through with no deflection. Alpha particles...
19. ### Thomson Scattering Hot Ionised Hydrogen Region

Homework Statement Consider photons crossing a large hot ionised hydrogen region with constant electron density ne = 5*105 m-3. Assuming that the photons and the electrons interact via Thomson scattering (with Thomson scattering cross section, σT = 6.65*10-29 m2, what is the thickness Δx that...
20. ### Throttling process (Joule Thomson coefficient)

This is a graph obtained during throttling process by keeping pressure and temperature at the inlet of the valve fixed and varying them at the outlet to get different isenthalpic curves for different inlet pressures and temperatures. Is it true that the sudden change in temperature of this...
21. ### Ratio of charges in thomson expt

Homework Statement three particles having charges 1:2:3 produce the same point on the photographic film in the thomson experiment. The masses are in the ratio of a) 1:2:3 b)3:2:1 c) 2:3:1 d) 1:3:2 Homework Equations a = F/m = Eq/m The Attempt at a Solution Since all the...
22. ### Discovering e/m Ratio: The J.J. Thomson Experiment Explained

This experiment aims towards finding e/m ratio and it is a very well known experiment that's why I will directly post my question. Why do we evacuate the glass tube?
23. ### Discovery of electrons - How did Thomson know they were particles?

Greetings, I have been having some fun in the last couple of days by looking at the details of historically significant experiments. One such is Thomson's discovery of the electron, in which he concluded that cathode rays were, in fact, composed of negatively charged, discrete particles. But...
24. ### Why Thomson scattering calls for a size-changing electron?

Why Thomson scattering calls for a "size-changing" electron? From my limited understanding of Thomson scattering, it only works for wavelengths comparable to the size of the electron. Because scattering was observed at a variety of wavelengths, it was assumed that the size of the electron must...
25. ### Thomson scattering and unpolarized light

Elastic scattering from a bound electron is classically described by considering the driven, damped harmonic oscillator model for the motion of a bound electron in a classical em-wave. The (non-relativistic) equation of motion is written as...
26. ### Joule Thomson Effect: Adiabatic Free Expansion & Derivation

Is the equation JT = (1/Cp)(2a/RT - b) valid for adiabatic free expansion of real gases only? How was this equation derived?
27. ### Finding the Radius of a Thomson Atom in Relation to Hydrogen Atom Radius

Homework Statement Assume that the density of positive charge in any Thomson atom is the same as for the hydrogen atom. find the radius R of a Thomson atom of atomic number Z in terms of the radius Rh of the hydrogen atom. Homework Equations The Attempt at a Solution I don't...
28. ### SCILAB - Thomson and Rutherford model

Homework Statement I have a problem with differential scattering cross section. It says: "division by zero". My full work is in attachment. q = 2; - charge of particle Q = 79; - charge of nucleus m = 4; - mass of particle M =...
29. ### Turboexpanfer joule thomson

good morning you need not give a lot of details, basically right or wrong, sometimes a little explanation would be nice: 1. in a turbo-expander (used in rotating equipment to produce refrigeration temperatures at its gas exist), the turbine section is said to have free flow--what is free...
30. ### Joule Thomson Effect: Exploring the Minor Difference

It occurs when a real gas is allowed to expand adiabatically we all know when a ideal gas is expanded adiabatically it temperature decreases so real gas should do the same with minor difference so what is all the fuss about we all know it will happen why is it given a special name
31. ### Energy Density with Thomson scattering

Homework Statement If ne represents the electron density and the interaction between particles is the photons scattering off of the electrons through the Thomson cross section, how low must the electron density be to cross the universe with no scattering? Homework Equations The size...
32. ### Basic Question about Thomson and Compton Scattering

Ok so I am doing a project on the derivation of the Compton Effect, and I would like to briefly discuss Thomson scattering, but I'm having a little trouble understanding what happens in Thomson scattering. This is what I think I understand so far: When a photon enters matter and interacts...
33. ### Why J.J Thomson use gold in his experiment for atomic model?

any can answer this? that why J.J Thomson strike gold by alpha particles in his experiment by which he propose model for atomic structure?
34. ### Compton vs. Raman vs. Thomson Scattering

I'm reviewing my scattering processes and can't quite pin down the difference between raman and compton... It sounds like Compton scattering is exactly the same as Raman scattering (with inverse-compton = raman stokes scattering; and normal compton = raman anti-stokes scattering). Also, just...
35. ### Searching for Joule Thomson and Thermal Expansion Coefficients of Methane

I've been scouring the web in search of a Joule Thomson coefficient value for methane, but so far no luck. I have the volume, temperature, and specific heat as well... so I could also use the coefficient of thermal expansion for methane.. but I can't find that anywhere either! Does anyone...
36. ### Thomson Scattering: What Is It?

Would you please explain more abot it? Thanks:smile:
37. ### MATLAB Draw Thomson cross section in polar plot by matlab

Well I'm supposed to draw Thomson cross section in polar plot by MATLAB software. Have I done it right? I mean does this figure that I got seem to be in polar plot or not? t = 0:.01:2*pi; r = 2.8179e-13 x = t,0.5*power(r,2)*(1+power(cos(t),2)) polar(t,x) Thanks
38. ### Where Can I Find a Thomson Model Alpha-Particle Scattering Curve?

Hello, For a course in experimental physics I need to obtain a curve of alpha-particle scattering as predicted by the Thomson model* (i.e. the plum pudding model). I am allowed to look this up so long as it is from a reputable source and I cite it. Does anyone know where I can find such a...
39. ### Understanding Thomson Scattering for Non-Experts

Can anybody provide me with information on thomson scattering for someone who hasn't done electrodynamics? I find ones like http://farside.ph.utexas.edu/teaching/jk1/lectures/node85.html but I don't know anything about solid angles and the scattering cross section is confusing me. I'm...
40. ### Bill Thomson, Harold Jeffreys and Dark Stuff

Is it by now conclusively established that the universe is made mostly of exotic dark matter and dark energy? I need reassuring that there is no escape from this still startling conclusion. The following cautionary tale will explain why I have the temerity to ask such a question: In the...
41. ### How Is the Joule-Thomson Coefficient Calculated Without Knowing Volume?

Hi. I need a little help with this question. I found a useful link below but can't figure out how to find the joule-thomson coefficient without knowing volume. I'd appreciate any pointers on this. Thanks. http://www.ccr.buffalo.edu/etomica/app/modules/sites/JouleThomson/Background3.html...
42. ### Exploring Atomic Models: Thomson, Rutherford, and Bohr

I am to explain whether the Thomson model of the atom fails at large scattering angles or at small ones...I obviously don't want the answer, but just some hints as to how I would determine this. Thanks in advance. I know that the Thomson model predicts that there should be less than 1 degree...