Is Feynman the "wise guy" in Zee's QFT book?

[apostolosdt]

Zee, in his QFT in a nutshell, tells that beautiful story about a "wise guy" who, through his annoying questions to the professor, actually describes a fundamental principle of quantum mechanics, essential to Feynman's approach to quantum phenomena (pp. 9 in Zee's). Now, Zee appears to imply that the "wise guy" is Feynman himself.

Just like most of you here, I have gone through various stories about Feynman, but I cannot recollect any passage referring to Feynman actually having said that. Is there anyone here in this forum that can clarify that point?

 

[George Jones]

Zee, in his QFT in a nutshell, tells that beautiful story about a "wise guy" who, through his annoying questions to the professor, actually describes a fundamental principle of quantum mechanics, essential to Feynman's approach to quantum phenomena (pp. 9 in Zee's). Now, Zee appears to imply that the "wise guy" is Feynman himself.

I get the impression that this is a fictional story concocted by Zee for pedagogical purposes. On page 8, Zee starts the story with "Suddenly, a very bright student, let us call him Feynman, asked ..."

 

[apostolosdt]

I get the impression that this is a fictional story concocted by Zee for pedagogical purposes. On page 8, Zee starts the story with "Suddenly, a very bright student, let us call him Feynman, asked ..."

Well, yes, sure it's a fictional story told by Zee, I get that. But what bothers me is this. Did Feynman ever actually either write, or teach, or say, or simply imply such a colorful example of his "sum over histories" concept? And Zee only borrowed it and made it into a fictional story?

 

[hutchphd]

It was Feynman's doctoral thesis. Or am I missing something?

 

[apostolosdt]

I should have been more precise---apologies!

In Zee's story, the professor is explaining the double-slit experiment when the `wise guy' starts repeatedly asking about the cases with more than two holes on the screen and more than two screens, etc. until the student throws his `bomb': an infinite number of holes on the screens so that there are no screens anymore!

That remark sounds very much like real Feynman's. So, in my original post, I asked whether Zee invented the entire story, or Feynman himself somewhere mentioned that `infinite number, thus no screen' thing, and Zee turned it into a good story.

Does anyone know anything about it?

 

[hutchphd]

Check this out. Nice review,might help

 

[apostolosdt]

Thank you very much hutchphd! That resolves the issue! It was after all Zee's idea. Thanks again.

 

[TSny]

So, in my original post, I asked whether Zee invented the entire story, or Feynman himself somewhere mentioned that `infinite number, thus no screen' thing, and Zee turned it into a good story.

Thank you very much hutchphd! That resolves the issue! It was after all Zee's idea. Thanks again.

There's a book titled Quantum Mechanics and Path Integrals by Feynman and Hibbs which was published in 1965. In the first chapter on pages 20 and 21, the authors discuss extending the double slit apparatus by adding more screens and more holes in the screens. I will quote a few sentences:

"Next, suppose we continue to drill holes in the screens D and E until there is nothing left of the screens."

After discussing this, they go on to say:

"Clearly, the next thing to do is to place more and more screens...and in each screen drill so many holes that there is nothing left. Throughout this process we continue to refine the definition of the path of the electron, until finally we arrive at the sensible idea that a path is merely height (x) as a particular function of distance (y), or x(y). We also continue to apply the principle of superposition, until we arrive at the integral over all paths of the amplitude for each path."

Also, on page 20 there is a diagram that is similar to the diagram in Zee's YouTube video at time 49:40 in the video.

 

[apostolosdt]

There's a book titled Quantum Mechanics and Path Integrals by Feynman and Hibbs which was published in 1965. In the first chapter on pages 20 and 21, the authors discuss extending the double slit apparatus by adding more screens and more holes in the screens. I will quote a few sentences:

"Next, suppose we continue to drill holes in the screens D and E until there is nothing left of the screens."

After discussing this, they go on to say:

"Clearly, the next thing to do is to place more and more screens...and in each screen drill so many holes that there is nothing left. Throughout this process we continue to refine the definition of the path of the electron, until finally we arrive at the sensible idea that a path is merely height (x) as a particular function of distance (y), or x(y). We also continue to apply the principle of superposition, until we arrive at the integral over all paths of the amplitude for each path."

Also, on page 20 there is a diagram that is similar to the diagram in Zee's YouTube video at time 49:40 in the video.

TSny, thank you so much! Although now the mystery deepens! (LOL) Was or wasn’t Zee aware of that passage? Feynman & Hobbs is a well known book, too well known to ignore. And my sarcasm extends to myself as well!