Feynman Definition and 649 Threads

Hi, I just ordered the Exercises for The Feynman Lectures on Physics and although the exercises in them appear to be very interesting, most of them come without answer. I'm just wondering if there is someone with answers to all of them or if there is a book or website which has them. Thanks

Hi all, This is just wild shot, since my memory is not what it used to be ... I remembered reading about Feynman pointing out an interesting fact, that the integration of the gaussian function \int_-\infty^\infty e^(-x x) dx = \sqrt[\pi] has to do with Pi. He then went on to show...

Does anyone know where I can download Richard Feynman lectures free?

I need help - Higgs for idiots: So, how a particle which have no mass without higgs (so it travels at c, and on feynman diagram we would draw its worldline at 45deg) can slow down or even be at rest when Higgs is switched on? Could anyone draw a feynman diagram?

Greetings, In Feynman's lectures - vol. 2 either chap 19, 21 or 23 - I think 23 (I'm at work and don't have the lectures here), Feynman shows in a capacitor that a changing E-Field induces a B-field, then he shows that the B-field induces a new E-Field (he calculates the E-field) and then...

I'm watching a youtube video () of an interview with Feynman. He says, "...there are a number of paradoxes with this quark picture...we've done some experiments at very high energy, hitting a proton with an electron...that can only be interpreted by supposing that the number of particles inside...

I'm not making any statements here, only asking questions. When I take two permanent magnets and I feel the repulsive force between them, Feynman QED says it is the momentum of the virtual photons "pushing" the magnets apart? Experiments have been done, forcing some of these virtual...

Lets say we have a process where: Particle B(P) -> v(p2) + k some particle effectively goes to an antifermion and a photon, with momentums P, p2, and k. And the diagram is just straightforward, in arrow to vertex, out photon and out antifermion from vertex. Now the arrow on the...

Consider the functional: (1) \mbox{ }e^{iW[J]} = \int d \hat{\phi} \mbox{ }e^{i\int d^4x \mbox{ } \mathcal L(\hat{\phi})+J\hat{\phi}} Define a Legendre transformation to get a functional in \phi(x) instead of J(x): (2) \mbox{ }\Gamma[\phi]=W[J(\phi)]- \int d^4x \mbox{ } J(\phi) \phi...

I hear a lot about "the feynman lectures", but is there any set of lectures that most people have in mind when they hear "the Feynman Lectures"? Or does that phrase really not point to a specific set of really good/popular lectures? I'm trying to find some to watch, but it seems like there...

I wonder... Would it be something like that?

Hi, Does anyone know where I can find the audio version of the "Feynman Lectures"?? I know not all of them are taped, but most are, I can't seem to find them anywhere. Help! Thanks.

As I state my questions, there are likely to be errors that I would appreciate being corrected. Beyond that, however, if the gist of the questions can be salvaged after correcting these errors, I would also like answers to your version of the questions. Both Feynman's summation over histories...

Feynman Looking for A "Particle Version" of QFT Hey, I think I read somewhere (though can't find it now) that Feynman was looking for a 'particle' version of quantum field theory which he didn't find but this instead led to the path integral approach of quantum mechanics. Can anyone shed any...

I have some well ordered feyman diagrams which have an incoming neutrino interacting at a vertex with a w boson and emitting an electron. since a neutrino can pass through some 18 light years of led without interacting, I'm wandering how a single neutrino interacts at this vertex?

Is this right? To calculate a scattering amplitude for a certain scattering event, you take the term in the wick's expansion of the S-Matrix that suits your situation best. Then you draw a Feynman Diagram that corresponds to the term in the wick's expansion, then just use the Feynman Rules to...

https://www.youtube.com/watch?v=http://www.youtube.com/watch?v=QMRGYkfzgs0

I've been in a very history of physics mood lately and have been rediscovering Feynman. I was watching the Nova special from after his death and SJMF was typed out from audiotapes of Feynman telling the stories. Does anyone know if there is anyway to get a hand on the original version as read by...

Homework Statement I am trying to prove that \displaystyle{\not} a \displaystyle{\not} b + \displaystyle{\not} b \displaystyle{\not} a = 2a\cdot b using the relation \{\gamma^{\mu},\gamma^{\nu}\} = 2g^{\mu\nu} Homework Equations The Attempt at a Solution If I work backwards...

I'm having a problem calculating the Feynman amplitude for the scalar scattering process \chi^+ \chi^- \to \chi^+ \chi^- for an interaction Lagrangian which is: \mathcal{L} = - g \chi^\dagger \chi \Phi - \frac{\lambda}{4} (\chi^\dagger \chi)^2 So far I have the 2 Feynman Diagrams for...

Homework Statement Hello all, thanks for reading... I was assigned to calculate feynman rules for the scalar QED theory via functional methods. The fields are a scalar complex field \phi, \phi^* and gauge field A_\mu, and the lagrangean is \mathfrak{L} = (D_\mu \phi)^* (D^\mu \phi) - m^2...

Has anyone read the Feynman Lectures of Physics*? I've heard about them and they seem pretty nice. I'm thinking of looking into them but wanted some feedback from someone who has already read them. I already know some of the basics and so I mainly wanted these to better my understanding of...

Hey all, I am just wondering if one can directly calculate the Einstein coefficient in spontaneous emission of, say, two-level atoms through feynman diagrams? I searched for sources in google but could not find anything. Thanks a lot for an answer! Wit best regards, blue2script

I was reading the Feynman lectures, on the parts that deal with optics, and he explains diffraction in a very interesting way. He imagines a diffraction grating to be made up of a long line of infinitesimal dipole oscillators, all oscillating in phase. What I don't understand is, in which...

Not looking for much of a discussion, just a simple answer. Did Feynman smoke cigarettes?

I always wanted to ask (but was afraid to) about the borders on the famous Feynman diagrams. As I understand, Feynman diagrams have the same age as Copenhagen Interpretation. So at that time it looked very logical: quantum behavior inside, but classical world outside. Outgoing particles are the...

Hi everybody, I'm new. I'm approaching to QFT in these months and I have a couple of questions about Feynman rules. The most of the books I have read (or tried to) explain feynman rules telling what you have to do when you have an internal or external line in a graph, and when you have a...

http://research.microsoft.com/apps/tools/tuva/index.html" has a transcript, timeline, and other interesting features. (Silverlight required.) I learned this from Slashdot: http://science.slashdot.org/story/09/07/15/1635245/Bill-Gates-Puts-Classic-Feynman-Lectures-Online?art_pos=4"

Hi everybody! I'm a new Physics Forums user and hope someone could help me out with my minor dilemma. I'm a PhD student in mathematical/theoretical physics and I' working on the Boltzmann equation in QFT. Up to now, there was no major emphasis on Feynamn diagrams - the approach was rather more...

how good Feynman Lectures are ? and if learn basic physics what mathematical physics book should i learn to learn core course physics ? Is Mathematical methods for physicists good enough ?

Is Feynman lectures on physics suitable for beginning physics (learn basics of physics) OR physics for scientists and engineers (Serway) ? i want to learn basics most powerful thx

Homework Statement Hello, I am trying to draw a Feynman Diagram at quark level for the decay sigma+ -> neutron + pi+.Homework Equations sigma+ -> neutron + pi+ uus -> udd + udbarThe Attempt at a Solution Well, the attachment is what I came up with. I have no idea if it's right to be honest...

which is the better series one can learn physics from? I've personally read feynman's but I haven't tried halliday's.

My library only had the first volume, I would love to read them all. Is it worth to buy them?. Its just that the shipping will be quite expensive to my country.

After summing up the rudiments of quantum mechanics Feynman tries to answer a question that readers might have at this point of his book, The Feynman Lectures on Physics, Vol. III, page 1-10.1. He writes, "One might still like to ask: "How does it work? What is the machinery behind the law?"...

There was a question several days ago related to visualizing the electro-magnetic field. I reminded me of a great passage from the Feynman Lectures on Physics. I won't quote the whole thing, but it is in section 20-3, "Scientific Imagination" (unfortunately I don't think the lectures are...

Homework Statement I'm working my way through Quantum Field Theory in a Nutshell by A. Zee. I'm religiously doing the exercises but since I'm doing it on my own (I'm not in school) I have no one to ask when I get stuck. Any hints would be appreciated. The problem is IV.7.5, on page 253 of...

can someone please explain the attached picture to me? if the electron and positron are just annihilating each other shouldn't the positron be going the other way? and shouldn't the antiquark be going the other way too? and what's up w/ the ->t thing at the bottom?

hello, I am trying to follow the arguments in Peskin pages 96-97 where the exponentiation of disconnected diagrams are performed. I think the 'proof' is too 'not detailed' and was wondering if there exists a better explanation elsewhere? My biggest question is the sentence on page 97 "The sum...

I'm reading a course in Introduction to QFT and I'm stuck at a problem. I'm hoping someone here could point me in the right direction or say if my assumptions are incorrect. Homework Statement Derive the Feynman rules and all diagrams at tree-level for \lambda \phi^3 theory using Wick's...

Homework Statement Hello :smile: The question is from "Advanced Physics" by Adams and Allday. It is from section 9 "The Physics of Particles", "Practice Exam Questions". It is question 11, part c. The level of this study is between school and University. Figure 9.5 represents a simple...

Can anyone recommend a good Feynman diagram calculator ?

I'm trying to learn Feynman diagrams from Srednicki's QFT book! Could someone retell and summarize in his or her own words what Srednicki is saying in the three paragraphs after equation 9.11? (I don't understand what the (2P)!/(2P-3V)! different combinations are, how Feynman diagrams are...

I'm learning QFT by reading Lewis Ryder's book, so my question in short is: how he arrives at Eq 7.57 and Eq 7.58? If you don't have the book, the question is: why are there Minkowski metric terms in the Feynman rules for a gauge field coupling to itself? If the answer is complicated, simply...

I got my final pick of books as extra readings/studying to supplement my rather deficient Physics C class. It's the Feynman lectures on Physics and Irodov problem book (and when my calculus is ready, I'll tackle Introduction to Mechanics by Kleppner and Kolenkow) How do you think should I...

...like in Photon-Photon-scattering. I know this doesn't make sense physically but the value for the diagram should still be computeable. If I want to put the expression for the matrix element together, I get a matrix, but it should be a scalar, right? Since the spinor bi-product is missing...

I'm not sure if this is the right place to post a graduate level course material, but I have a question about perturbative expansion of the 2n-point function of a scalar field theory. Homework Statement First, the question: In which space (position or momentum) is the topological distinctness...

A friend introduced me to this very strange, very funny video of Richard Feynman. Has anyone seen it? What a guy...:smile:

Homework Statement Draw the Feynman diagram for: e^{-} + p \rightarrow n + \upsilon_{e} Sorry, I don't know how to make everything even but you should get the gist. Homework Equations The Attempt at a Solution Well, what I have is the electron and proton annihilating(and this...

Homework Statement Q) Neutral pion decays into 2 photons which then decay into electron-positron pairs. What would the feynman diagram look like? :confused: