> I tried to track down the original source of this idea ... Beiser cites an article from the UN, which itself cites a 2006 paper about using two types of desert sand from China in concrete. But that paper doesn’t mention the roundness of the particles at all.
This seems to be a fairly common pattern where a citable source (Beiser's book and the UN article) makes a mistake, that then propagates everywhere as common knowledge even though it's incorrect. There are many well-researched blog articles like this out there, where the author has dug deep, done the hard research, and found mistakes at many levels, but because it's not in what academia or Wikipedia considers a "citable" source, the mistaken assertion continues to be propagated. Until someone manages to present it in an academically acceptable format, if that happens at all.
Solving the "what should be a citable source" problem is complicated, but in the interim, I hope we can at least find a way to transfer these well-researched findings and corrections from non-academic sources to citable forms regularly and easily.
The problem is that what defines a “citable source” for Wikipedia is loose at best and malicious at worst. There are many examples where “improper” sources are accepted, especially in social matters, because they benefit a certain viewpoint. STEM is, for the most part, decent, but anything covering the life of people needs to be considered carefully due to the lack of several types of important sources and the biases present on many people’s pages.
If you're bilingual, it's often useful to read a wikipedia topic in more than one language, as the editorial slant may be different in different languages.
The BBC Maths and Statistics programme 'More or Less' has coined a term for statistics like this - 'Zombie Statistics'. An initial, often misquoted fact, which is useful as a soundbite and gets repeated over and over and over again, despite multiple debunkings.
This seems to be a fairly common pattern where a citable source (Beiser's book and the UN article) makes a mistake, that then propagates everywhere as common knowledge even though it's incorrect. There are many well-researched blog articles like this out there, where the author has dug deep, done the hard research, and found mistakes at many levels, but because it's not in what academia or Wikipedia considers a "citable" source, the mistaken assertion continues to be propagated. Until someone manages to present it in an academically acceptable format, if that happens at all.
Solving the "what should be a citable source" problem is complicated, but in the interim, I hope we can at least find a way to transfer these well-researched findings and corrections from non-academic sources to citable forms regularly and easily.