Talk:Eddington number

This article was copy edited by Wahrmund, a member of the Guild of Copy Editors, on December 22, 2014.Guild of Copy EditorsWikipedia:WikiProject Guild of Copy EditorsTemplate:WikiProject Guild of Copy EditorsGuild of Copy Editors articles

Physics High‑importance

	Physics portal This article is within the scope of WikiProject Physics, a collaborative effort to improve the coverage of Physics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.PhysicsWikipedia:WikiProject PhysicsTemplate:WikiProject Physicsphysics articles
High	This article has been rated as High-importance on the project's importance scale.

"I believe there are 15 747 724 136 275 002 577 605 653 961 181 555 468 044 717 914 527 116 709 366 231 425 076 185 631 031 296 296 protons in the universe and the same number of electrons." Did he actually said thatc? How would that be written in text then? — Kieff | Talk 06:54, Sep 20, 2004 (UTC)

Actually, it's a quote from his Philosophy of Physical Science. According to a lecture given by Chandrasekhar, Bertrand Russell asked Eddington if he had computed this number himself or if he had someone else do it for him. Eddington replied that he had done it himself during an Atlantic crossing! (Chandrasekhar, S. "Eddington: The most respected astrophysicist of our time").

I, however, have a question of my own - what exactly is the connection between this massive number and 1/137? The article doesn't explain it. Were they both called Eddington number? Is there a physical connection between them (in which case Eddington's article needs to be changed to reflect this)? Confusing Manifestation 14:15, 5 May 2006 (UTC)[reply]

There is no direct connection. Having reworked his book "Fundamental Theory" published posthumously, Eddington takes the measured values of 3 constants, The Rydberg Constant, The Speed of Light and Faraday's Constant and then adds to that the assumption that the Fine Structure Constant is exactly 137 and N is 3/2 x 136 x 2^256 (50% up on the above value). From that he calculates every other fundamental constant from the mass of the universe to the mass of an electron. If anyone is that interested I'll email them my spreadsheet calculations. Rgoodhand 00:57, 29 January 2007 (UTC)[reply]

I am not quite certain if this comment makes much sense here (not being a physicist), but I think this page is not very "non-physicist"-friendly. I say this as I got here by searching "number of electrons in the universe" in a search engine and this page was presented as the top result. Albeit the search result being good, I didn't understand a lot of the information (as a previous comment pointed out: what is the relation between N_Edd and α ?) and I was missing some guidance on how to actually read the value for α as I wasn't familiar with the presented notation on uncertainty, which is explained in Standard Uncertainty. Furthermore, although stated as such, maybe a pointer would be great stating the difference between the stated value for α, which is a value obtained experimentally, and the commonly accepted value, which is slightly different, and given on the related page Griphook (talk) 15:31, 24 January 2014 (UTC)[reply]

Actual number of protons

Are the notation N_Edd and the name "Eddington number" still used to talk about the number of protons in the universe? Or are they only used historically, in the context of Eddington's conjecture?
If they are currently used, this article should mention the currently accepted figure for this number. If not, it should point to the appropriate other article. --Macrakis (talk) 18:51, 9 November 2015 (UTC)[reply]