What changes would need to be made to the following question for it to be on-topic on this site?

I'm trying to determine:

1. why this is the best number for its purpose given how confusing it is
2. if there is a better number that would be easier for a lay person to understand - to help more people understand and appreciate physics

I feel I have expressed this in the question but if everyone is shutting it down there must be some sentences or question marks that I am missing

• Note: only users with reputation above 10k, and the question's author, can see the content at the link. Low-reputation users will see an error page telling them that the question has been hidden. – rob Mod Mar 24 '20 at 11:33
• – rob Mod Mar 24 '20 at 11:35
• What do you mean by "better number"? Do you mean a more accurate estimate, or do you mean a number that is easier for the layperson to comprehend? If it's the second one, why would we want to present an incorrect number. If it's the first one, can you point to any reasons that the current numbers are inaccurate and need of change? The reasons you seem to list in your linked question mostly seem to be misunderstandings to me. – JMac Mar 24 '20 at 12:16
• Your two points are subjective. I would start with making your question more objective. Also your question wasn't closed due to punctuation errors. – BioPhysicist Mar 24 '20 at 13:49
• The text of the question you've linked reads basically like a rant about how you don't like (whatever it is you don't like), while at the same time not even being clear about what it is that you don't like. If you're looking for places to start editing, I'd suggest starting from scratch and then making sure not to include anything that even smells like 'rant'. (Hint: since you're the one writing, it obviously won't smell like 'rant' to you. Instead, everything to do with your strongly-held opinions needs to go.) – Emilio Pisanty Mar 24 '20 at 15:11
• @JMac by better number i mean a number of similar magnitude that represents something else that one could easily picture in their head (not accurate but say the number of grains of sand that could fit in the empire state building = 10^80) and would get across the point that it is the biggest number of physical things that we can have. secondly the wording that is always used implies a different definition then what physicists actually use and comprehend – user1886419 May 14 '20 at 8:24
• @EmilioPisanty ignoring the text, what about the content. what can i do to better express the content. what do you think about when i say that's more than the number of atoms in the universe? does that make sense to you? does your non-physics friend understand what that means when you say it to them? do they know you mean observable universe? what the observable universe is? – user1886419 May 14 '20 at 8:28
• @AaronStevens is there a particular sentence or paragraph you could point to that sounded subjective but that you could do a better job writing objectively then poor me? – user1886419 May 14 '20 at 8:29
• @user1886419 Now it just feels like you're ranting at me. To the best that I can tell, there's a perfectly reasonable calculation, which is already explained in a thread on this site, and which for whatever reason you have decided you cannot and will not accept. That's not a recipe for a constructive thread - the only solid thing here seems to be that you won't accept the answer, but you won't (or can't) express any real or solid criticism of why you think it's flawed. And the tone of the question and your comment above makes me personally not want to touch any of this with a ten-foot pole. – Emilio Pisanty May 14 '20 at 10:08

As one of those who voted to close I feel I should respond. I voted to close because I do not think this was a question about physics. No physicist I know cares about the calculation of the number of atoms in the observable universe. It is just one of the superficially impressive statistics thrown around by popular science programs.

Questions about the average density of the universe and the size of the observable universe are very much on topic because they are related to the spacetime geometry in an important way and neither number is as precisely known as we would like. From these you can work out the number of atoms in the observable universe, but this is at best recreational physics.

• Does this mean that "questions physicists do not care about" cannot be considered to be physics questions? – BioPhysicist Mar 24 '20 at 19:45
• The OP asked for “help with alternate wording”. – G. Smith Mar 24 '20 at 19:57
• No physicist I know cares about the calculation of the number of atoms in the observable universe. Eddington thought the number of protons (or electrons) in the observable universe was so interesting that he had a theory about its exact value as an integer. So this general idea has been of intense interest to some physicists in the past, possibly including Weyl and Dirac as well. – G. Smith Mar 24 '20 at 20:23
• you assume only physicists use this site. it is a question and answer site about physics, by definition it is not a site for physicists. how do you become a physicist? have to start somewhere? have to ask questions. and have to understand things in lamen terms. and you say questions about the number of atoms in the universe are on topic. how does this help me reword my question to fit site rules? – user1886419 May 14 '20 at 8:14

Change the title to “Number of nucleons in observable universe”.

Change the body to “How do physicists estimate this number to be roughly $$10^{80}$$?”

• How is that a different question from the duplicate question? – BioPhysicist Mar 24 '20 at 17:26
• It isn’t. I’m just trying to make the OP understand how not to rant. This would still be closed as a duplicate. – G. Smith Mar 24 '20 at 17:28
• @AaronStevens It chooses to use nucleons instead of atoms; but I'm not sure if that would still follow the spirit of OP's question. – JMac Mar 24 '20 at 17:28
• We’ve already been over this. There are no atoms in stars. – G. Smith Mar 24 '20 at 17:29
• The OP did not get 12 downvotes and 0 upvotes because they wrote a duplicate. They got slammed for an unclear rant. – G. Smith Mar 24 '20 at 17:31
• @JMac Right, since they seemed more interested in talking in layman's terms, and I would guess "nucleon" is not as well known as "atom" – BioPhysicist Mar 24 '20 at 17:35
• The problem isn’t that the OP mentioned atoms. – G. Smith Mar 24 '20 at 17:36
• @G.Smith We were over this, but I thought even you concluded that "stars aren't made of atoms" was more of a "maybe it's just me" type of situation, and definitely didn't represent consensus. I think editing the question based on your opinion of ions being atoms isn't particularly good advice, and possibly more confusing here, since it does actually change the question. – JMac Mar 24 '20 at 18:09
• @JMac I was just being polite. I do not actually know any physicists who consider an ion to be an atom. If you think I have offered a poor answer, you should downvote it. I think the OP is entitled to actually get suggestions for improvement, not just criticisms of what they wrote. – G. Smith Mar 24 '20 at 18:43
• @G.Smith And at the time I was looking for any references where people say that ions are not atoms; because I can only find sources to the contrary. I would figure that if all the physicists you know agree that ions are not atoms, there must be some good accessible information about that somewhere, so again I would ask for any support for that. – JMac Mar 24 '20 at 18:47
• Wikipedia’s “Atom” article is inconsistent on this, but at least this sentence is correct: “Every atom is composed of a nucleus and one or more electrons bound to the nucleus.” This is not the place to debate whether all ions are atoms so I am not going to continue doing so. – G. Smith Mar 24 '20 at 18:49
• Before I get slammed for my sloppy use of the word “ion”, I am talking about bare nuclei with no bound electrons, as in most stellar plasma. – G. Smith Mar 24 '20 at 18:54
• I also should not have said “There are no atoms in stars.” There are in the photosphere. As far as I know, the hotter interior is fully ionized. If I’m wrong about this, someone please let me know. – G. Smith Mar 24 '20 at 19:07
• anyone that reads the question would be able to tell that OP does not want to understand how the calculation is made.interesting fruitless attitude. OP wants to understand why it is never described honestly, how to describe it honestly, without using math, or big words. i am trying to help evangelize the most amazing thing people have ever calculated. please help – user1886419 May 14 '20 at 8:18