Update: I fixed the split by adding a command in the HTML source that re-internationalizes the canonical URLs that are served to Disqus. What should have been canonical is canonical again and the global TRF community is reunited. ;-) That's why I moved this blog post to the past.Either Disqus, the world's top web commenting company that has been running the platform for discussions on this blog for several years (after I migrated from Haloscan/JS-Kit/Echo by a difficult process), or Blogger, a company within Google, has changed something in the way how the URLs are transferred in between the two servers.
Consequently, as John Gsheep has pointed out (although a bit more mysteriously than this blog says), all the comments posted to one national edition of this blog are invisible to the visitors of all other national editions right now. The problem has existed for one day. Is there a way to see the comments by fellow members of the TRF community again, or have we been segregated into decoupled national cliques by dozens of iron curtains?
The canonical fix (already mentioned in 2012) is to use the main i.e. American edition of this blog whose URL is
motls.blogspot.com/ncr/ (green desktop)Note that when people outside the U.S. open a blog in the blogspot.com domain, e.g. this one, it gets normally redirected to the national edition such as motls.blogspot.co.uk (the Britons have the 2nd most important domain) or motls.blogspot.cz (which I normally see) or one of the hundred or so other national editions.
However, when you use the URL with "blogspot.com" and add "/ncr" to the URL (which stands for "no country redirect"), you will keep on using the American *.com edition of the blog even if you're outside the U.S. You will stay at blogspot.com and only the "/ncr" disappears in the URL when you're quickly redirected. If you want to know, Americans and/or the native *.com visitors (almost the same groups) represent almost exactly 50% of the TRF traffic.
This "nationalized" behavior of the blogspot.com blogs (and other Google pages) has been adopted some five years ago. Google made it possible to localize national legal problems with the content to the "small editions" which I consider a good idea because countries where the freedom of speech isn't considered a good idea at least don't harm the users in civilized countries too much. (Google explicitly calls it selective censorship.)
So I kindly ask everyone outside the U.S. who expects the usual heavily international discussions we're used to to change the bookmarks to the "blogspot.com/ncr/" format. The rest of the URL should remain unchanged.
Maybe the change will be reverted. But maybe it won't.
If someone could find a way to fix the Blogger HTML template so that the default, international, i.e. American URL with *.com is used as an identification globally again, I would be grateful.
Note that the Disqus discussion threads are always embedded as "iframes" (a reason why the Mathjax LaTeX mathematics can't be used in the comments). If you view the source of a Disqus frame e.g. in a Czech edition of the blog, you will realize that the frame has URL
view-source:http://disqus.com/embed/comments/?base=default&version=85ba7336856f5be9db0e468752c2dad5&f=thereferenceframe&t_u=http%3A%2F%2Fmotls.blogspot.cz%2F2016%2F03%2Fweinbergs-deconstruction-of-measurement.html&t_d=The%20Reference%20Frame%3A%20Weinberg%27s%20%22deconstruction%20of%20the%20measurement%22%20isn%27t%20wrong%20but%20it%27s%20pointless&t_t=The%20Reference%20Frame%3A%20Weinberg%27s%20%22deconstruction%20of%20the%20measurement%22%20isn%27t%20wrong%20but%20it%27s%20pointless&s_o=descYes, you can open Disqus comment iframes separately as whole pages, without my original blog post. ;-) If you replace one *.cz by *.com in the URL, the American/global comments reappear so it's all about this one wrong suffix.
Even though I do like the idea of the separate national domains, as I mentioned, the segregation of the Disqus threads is a serious enough glitch so that I instantly changed my own bookmarks from *.cz to *.com/ncr.
Here you have a random Disqus help page about the split threads and missing comments. I think that the identification of the threads always depends on "url", not "identifier", but it's been misbehaving for a day. (Disqus would prefer people to use "identifier", but things may become more complicated if you need to construct and invent new identifiers for blog posts etc.)
Update I: I have verified that the regression is due to changes at Disqus. The HTML source makes it clear that Blogger is serving the nice canonical *.com addresses everywhere. Disqus just manages to ignore those settings and extract the blogspot.cz URL from another, unconstitutional place.
Update II: I would swear the previous paragraph was right a minute ago. But now, the source of a HTML blog shows the URLs with *.cz even though they're obtained from the Blogger variables with "canonical" in it... See e.g. the outrageous line
var disqus_blogger_canonical_homepage_url = "http://motls.blogspot.cz/";in the source. So it's some bad change of variables at the Blogger side! If they prevented me from using canonical variables with *.com, it would be more likely that Google has actually made the split deliberately. That's harsh.
Update III: I found a Blogger forum request where another user has noticed that the canonical variables have disappeared at Blogger. He or she is told to switch to "prevent redirect". I am probably going to do so, too. Also, Disqus' Twitter makes it clear that Disqus realizes that Blogger started to serve split-inducing URLs to Disqus.
Update IV: I made my own solution – added two lines to the HTML source of TRF which restores the canonical, *.com form of the variables called "canonical". Search for .replace in the comments or in the "view source" of this page. This returned the behavior as of days ago, and you're encouraged to use the national editions of the blog posts here again.