137

E

el es

Registered Senior Member
I don't know a deeper meaning of where it comes from, but:
www.quantamagazine.org

Physicists Nail Down the ‘Magic Number’ That Shapes the Universe

A team in Paris has made the most precise measurement yet of the fine-structure constant, killing hopes for a new force of nature.
www.quantamagazine.org www.quantamagazine.org
bigthink.com

The strange number 1/137 shows up everywhere in physics. What does it mean?

Does it have a deeper significance — or is it just a number? Unfortunately for physics enthusiasts, 1/137 is no more significant than 3.14.
bigthink.com bigthink.com

I don't get the Feynman Conjecture. Does anyone else understand it?
 

The Mysterious 137 – Richard Feynman

If you have ever read Cargo Cult Science by Richard Feynman, you know that he believed that there were still many things that experts, or in this case, physicists, did not know. One of these 'unknowns' that he pointed out often to all of his colleagues was the mysterious number 137.
feynman.com feynman.com

Somewhat helpful.
 
TheVat said:

The Mysterious 137 – Richard Feynman

If you have ever read Cargo Cult Science by Richard Feynman, you know that he believed that there were still many things that experts, or in this case, physicists, did not know. One of these 'unknowns' that he pointed out often to all of his colleagues was the mysterious number 137.
feynman.com feynman.com

Somewhat helpful.
Click to expand...
I've read that link 4 times now and I can't for the life of me see how it is not ballocks.

This Bill Reimers stuff sounds all wrong. First of all, 137 is not the odds that an electron will absorb a photon. The Fine Structure Constant, α is the reciprocal of 137.03......., which is itself not an integer, because α = e²/2ε₀hc, so its reciprocal is just the non-integer number that results from that calculation. Secondly I don't see why 137 protons in the nucleus means "you get 137 photons". What can that mean? Nor do I see why that, if true, would mean "100% absorption". And absorption of what, under what circumstances, and so what? It sounds like gobbledegook.

And when it comes to the conjecture, where is the conjecture stated? I couldn't see it anywhere in the passage of Feynman's that is quoted. There seems to be something about a link to some quantity called "p". As far as I can see, after re-reading it several times, it looks as if by "p", it may mean π. But then the quote from this guy Gibson speaks of the conjecture being something to do with a connection between α and some other quantity, called "n", the identity of which is not described anywhere in the article.

Frankly, I'm left none the wiser and wondering who wrote this stuff.

Maybe a physicist can explain if I'm missing something.
 
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James R said:
What's the Feynman Conjecture?
Click to expand...
I had to look it up.

It seems to be a re-statement of the magic number 1/137. I'm not sure how it's a conjecture.

"Physicist Leon M. Lederman ... [noted] that not only was it the inverse of the fine-structure constant, but was also related to the probability that an electron will emit or absorb a photon—i.e., Feynman's conjecture.**"


"**There is a most profound and beautiful question associated with the observed coupling constant, e, the amplitude for a real electron to emit or absorb a real photon. It is a simple number that has been experimentally determined to be close to −0.08542455. (My physicist friends won't recognize this number, because they like to remember it as the inverse of its square: about 137.03597 with about an uncertainty of about 2 in the last decimal place. It has been a mystery ever since it was discovered more than fifty years ago, and all good theoretical physicists put this number up on their wall and worry about it.) Immediately you would like to know where this number for a coupling comes from: is it related to p or perhaps to the base of natural logarithms? Nobody knows. It's one of the greatest damn mysteries of physics: a magic number that comes to us with no understanding by man. You might say the "hand of God" wrote that number, and "we don't know how He pushed his pencil". We know what kind of a dance to do experimentally to measure this number very accurately, but we don't know what kind of dance to do on the computer to make this number come out, without putting it in secretly!"

137 (number) - Wikipedia

en.wikipedia.org en.wikipedia.org
 
DaveC426913 said:
There is a most profound and beautiful question associated with the observed coupling constant, e, the amplitude for a real electron to emit or absorb a real photon.
Click to expand...
The link I posted is probably crap - I posted it because it had that Feynman quote. The "solution" posted below it was opaque to me. exchemist, sorry if I sent you on a dumpster dive. Somehow I had hope that a site called feynman dot com would do better than that.
 
TheVat said:
The link I posted is probably crap - I posted it because it had that Feynman quote. The "solution" posted below it was opaque to me. exchemist, sorry if I sent you on a dumpster dive. Somehow I had hope that a site called feynman dot com would do better than that.
Click to expand...
In fact, from DaveC426913 's post the light may be starting to dawn. That suggests Feynman's conjecture was the original idea that α was related to the probability that an electron will emit or absorb a photon. Does this perhaps refers to the virtual, rather than real, photons that in QFT are said to mediate the EM interaction, i.e. was it a conjectural insight at the birth of QFT to which Feynman contributed so much?

But if I search the web for "Feynman Conjecture" I draw a blank, so it seems hard to corroborate.

Thanks anyway for trying: we may get there in the end.....
 
It's something about a polygon with 137 sides and the distance from the center to the center of a side, but I got lost after that.
 
el es said:
It's something about a polygon with 137 sides and the distance from the center to the center of a side, but I got lost after that.
Click to expand...
Yes, this prof Gilson (not Gibson, my mistake earlier) seems to be turning an n-sided polygon into a circle at the limit as n -> ∞ . But I strongly suspect what has happened is the notation has got garbled on the web page TheVat found for us. It looks as if π has come out as p, the subscript suffices on n have been turned into superscripts and there may also be a small p as well as a Capital P and π, all confused. So I can make neither head nor tail of it either. Perhaps if someone can find a clean version of Gilson's "solution", we can have another go.

But this suggests the "conjecture" is that α is related in some way to π and not, as the quote in DaveC426913 's post seemed to me to suggest, that it was to do with the role of α in determining the probability of electrons emitting or absorbing (virtual?) electrons. So a mathematical conjecture rather than a physical one.

I must say I am dubious about Gilson's idea because, as I said earlier, α is not 1/137, it is 1/137.035999177...... i.e. not an integer at all. So I can't see how a mathematical relationship arriving at the integer 137 can be any kind of explanation.

But I'm not an expert in this area. I have only come across α in the context of the QM of spin-orbit coupling, i.e. the energy difference between an electron whose spin is aligned with its own orbital magnetic moment, as compared to one whose spin is opposed to it, which is important understanding the atomic spectra of elements. It was presented to us, at university, as just a constant we need to know about, without any investigation of its importance in other aspects of physics.
 
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