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Path Integral Simplified

Started by josephpalazzo, May 12, 2014, 08:23:49 AM

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josephpalazzo

You’ve probably heard many crazy ideas, and most of the time, they are just that, crazy. But once in a while one of those crazy ideas turns out to be correct. Feynman’s idea of the path integral was one of those crazy ideas. In this blog, you will see how Feynman put his "crazy" idea into a mathematical formulation with results that were equivalent to QFT.

Path Integral Simplified

Any comments would be appreciated.

Jason78

I got as far as time slicing before my brain gave out. 
Winner of WitchSabrinas Best Advice Award 2012


We can easily forgive a child who is afraid of the dark; the real
tragedy of life is when men are afraid of the light. -Plato

josephpalazzo

There's an anecdote as told by Zee in Quantum Field Theory in a Nutshell :

In a double-slit experiment, a student asked: "what if you bore a third hole in the screen?" The professor replied,"Clearly, the amplitude for the particle to be detected at O is now given by the sum of three amplitudes." The professor was just about to continue  when the student interjected again, "What if I drill a fourth and a fifth hole in the screen?" Now the professor is losing patience, "All right, wise guy, it is obvious that we just sum over all holes. "  But the student said, "What if I drill an infinite number of holes so that the screen is no longer there?" The professor sighed:" Let's move on, there's a lot of material to cover in this course". That student was Richard Feynman.


Solitary

Quote from: josephpalazzo on May 12, 2014, 08:23:49 AM
You’ve probably heard many crazy ideas, and most of the time, they are just that, crazy. But once in a while one of those crazy ideas turns out to be correct. Feynman’s idea of the path integral was one of those crazy ideas. In this blog, you will see how Feynman put his "crazy" idea into a mathematical formulation with results that were equivalent to QFT.

Path Integral Simplified

Any comments would be appreciated.

If you can explain this so Casparov realizes it's about particles you are a genius. Solitary
There is nothing more frightful than ignorance in action.

Solitary

Quote from: josephpalazzo on May 13, 2014, 06:38:55 AM
There's an anecdote as told by Zee in Quantum Field Theory in a Nutshell :

In a double-slit experiment, a student asked: "what if you bore a third hole in the screen?" The professor replied,"Clearly, the amplitude for the particle to be detected at O is now given by the sum of three amplitudes." The professor was just about to continue  when the student interjected again, "What if I drill a fourth and a fifth hole in the screen?" Now the professor is losing patience, "All right, wise guy, it is obvious that we just sum over all holes. "  But the student said, "What if I drill an infinite number of holes so that the screen is no longer there?" The professor sighed:" Let's move on, there's a lot of material to cover in this course". That student was Richard Feynman.


That really is a good question, and I'd like to know the answer---an Aleph of particles? Solitary
There is nothing more frightful than ignorance in action.

josephpalazzo

Quote from: Solitary on May 13, 2014, 11:44:40 AM
That really is a good question, and I'd like to know the answer---an Aleph of particles? Solitary

The answer is in the OP: the Path Integral.

josephpalazzo

Quote from: Jason78 on May 13, 2014, 05:29:59 AM
I got as far as time slicing before my brain gave out. 
It's not much different than integrals, just the time is parceled and use the sum instead of an ordinary integral.

Berati

Quote from: josephpalazzo on May 12, 2014, 08:23:49 AM
You’ve probably heard many crazy ideas, and most of the time, they are just that, crazy. But once in a while one of those crazy ideas turns out to be correct. Feynman’s idea of the path integral was one of those crazy ideas. In this blog, you will see how Feynman put his "crazy" idea into a mathematical formulation with results that were equivalent to QFT.

Path Integral Simplified

Any comments would be appreciated.

I believe the correct answer is 42.
Carl Sagan
"It is far better to grasp the universe as it really is than to persist in delusion, however satisfying and reassuring."