Feynman Definition and 617 Threads

I remember reading a discussion by Feynman somewhere. He talks about parity and charge conjugation in terms of a hypothetical scenario involving "radio communication" with an alien civilization living far off in outer space. I don't remember the name of book I read this in. Does anyone know...

Hello everyone! A question came up as I was reading Chapter 24 of the Feynman Lectures book. To more specific, it's the comments after Eq. (24.2) on the first section---called "the energy of an oscillator". I don't quite get it. Thank you very much! :smile: "Now let us consider the...

"If we come to the case of flying saucers, for example, we have the difficulty that almost everybody who observes flying saucers sees something different, unless they were previously informed of what they were supposed to see. So the history of flying saucers consists of orange balls of light...

Hi What is the physical interpretation of Feynman path integral? Thanks :smile:

Good morning, After Feynman formulation's of quantum mechanics, he expressed the propagator in function of path integral by this formula: $G(x,t;x_i,t_i)=\int\int exp{\frac{i}{\hbar}\int_{t_i}^{t}L(x,\dot{x},P)dt'}DxDp$ the question is how we can define the integral measure Dx and Dp? thanks

I'm pretty new to the particle physics world, and modern physics in general, so bear with me. I also don't have a book yet, so it's kind of messed up I'm a bit confused by a few apsects of feynman diagrams, although my confusion actually lies much deeper. Looking at this diagram...

Can I run something by you all please? Feynman asks us to believe that calculating where a photon goes involves us suspending our perception of nature, and that only by working out every path it could take are we able to actually work out where it will end up. We're also told that time...

I am pretty new to the subject and hope someone can give me certain links to start off. We can express the time evolutions of a quantum mechanical state of a system as : |psi(Xf,T)> = Gv(Xf,T;X0,0) |psi(X0,0)> Now Gv can be expressed as a discretized Feynman Path integral which comes out...

Hi, I'm seeking for a software, witch will alow me to easily draw Feynman diagrams. I have currently found: FeynMF: LaTeX package. Not very nice to use, but very good quality diagrams FeynmanDraw: Very primitive WIN software. Not fine diagrams. FeynDiagram: C++ source for drawing...

Hi, I'm seeking for a software, witch will alow me to easily draw Feynman diagrams. I have currently found: FeynMF: LaTeX package. Not very nice to use, but good quality diagrams FeynmanDraw: Very primitive WIN software. Not fine diagrams. FeynDiagram: C++ source for drawing. Complicated...

I'm looking for some excellent references on Feynman diagrams, from an overview of the basics to a description of the relation between the diagrams and the heavy duty mathematics that they represent. Any information would be appreciated.

Can the amplitude and phase associated with each of the paths in the Feynman path integral be connected to geometric attributes of that path? For example, is the amplitude and phase connected to how long the path is or how much it curves or how much it deviates from the geodesic?

Plate with slits, on rollers, a la Feynman In one of Feynan's lectures, he describes a thought experiment about trying to 'beat' the uncertainty principle. Without going into all the details, this version of the two-slit experiment has the diffracting plate mounted on rollers. The text and the...

hi all, I've been busy collecting the mp3's of the original tapes of Feynman lectures on physics during the 1960's. So far - using mainly Kazaa and dc++ - I've found nearly all the lectures of Volume 1 and 3. The lectures of Volume 2 are quite hard to find. Does anyone here know a database...

A while ago I made a post asking why light diffracts and was directed to QED by Feynman. I have now read the book (or the relevant part at least) and it explains diffraction by the number of possible routes of photons through an aperture as being reduced when the is gap made smaller, and...

As I was recalling one of the Feynam lectures, I rememberd him saying that the only phenomena QED couldn't explain are the physics of the nucleus and one other that I can't remember...gravity maybe? Anyway, since QED deals with atomic particle interactions it was the nuclier one that surprised...

Richard Feynman in his Physics lectures and diagrams show a free electron emitting a photo and/ or absorbing a photon. He (They?) always show the electron being deflected. My question is if the photon has no mass how can or why does the electron react by being deflected in motion? If it is a...