Scrapped justdropped data, patched:
+++ b/cia-2010-covert-communication-websites/cdx-post.sh
@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 # Post process the output of cdx.sh to enrich IDs even further, and reconstruct easier to Web Archive inspect domain names.
-grep -P -e '([^,)]+)\)\/\1\.swf|\)/[^/]+.jar|([^,)]+),([^,)]+),([^,)]+)\)/cgi-bin/[^/]+\.cgi' "$1" |
-  sed -r 's/\).*//' | awk -F, '{ printf("%s.%s\n", $2, $1) }' | uniq -c | awk '$1 == 1{ print $2 }' | tee $1.post
+grep -P -e '([^,)]+)\)\/\1\.swf|\)/[^/]+.jar|([^,)]+),([^,)]+),([^,)]+)\)/cgi-bin/[^/]+\.cgi' "$1"|
+  sed -r 's/\).*//' | awk -F, '{ printf("%s.%s\n", $2, $1) }' | uniq -c | awk '{ print $2 }' | tee $1.post
and then:
./hupo-cdx-tor.sh out 'news|headline|internationali|mondo|mundo|mondi|iran|today' 2006 2022
web.archive.org/web/20110203041325/http://financecentraltoday.com/
web.archive.org/web/20110202221328/http://thenewsofpakistan.com/
web.archive.org/web/20050424123432/http://www.pokernewsweb.com/ likely legit in the intended emulated style
web.archive.org/web/20100923090646/http://mideasttoday.net/
web.archive.org/web/20100206221718/http://euronewsonline.net/
web.archive.org/web/20110208063146/http://news-and-sports.com/ Hit.
web.archive.org/web/20110202054628/http://intoworldnews.com/ hit.
web.archive.org/web/20110207171340/http://mydailynewsreport.com/ hit
web.archive.org/web/20050508220858/http://www.asianewsupdate.com/ this looks like the exact format of legitimate site the CIA was emulating. Copyright 2005, a CGI link to as: www.asianewsupdate.com:80/cgi-sys/FormMail.cgi There's a phone there 01 647-0910 so seems less likely?
2010. JAR unarchived. rss, split image
2010. JAR. Split header.
2011. JAR unarchived. Split header.
2011. JAR. a.newslink, a.newslinkalt.
2011. Arabic. RSS.
web.archive.org/web/20110129115400/http://kmirano.com/ shallow but off style? Has a kmirano.sfw... viewdns.info/iphistory/?domain=kmirano.com says 211.1.224.71 Japan NTT SmartConnect Corporation 2012-01-11
2011. JAR. Copyright 2008. Split header and other images. They are obsessed about CDMA (2G).
2011. JAR. split header, RSS.
2010. Suspicious. But no clear fingrenprint. Also not as shallow as others. Also Joomla based which would be novel.
2010. JAR.
newspapergateway.com/ web.archive.org/web/20110208070309/http://newspapergateway.com/ hard to tell but generally off. Has both JAR and SWF.
2011 Farsi. JAR. RSS.
2010 JAR. Split header, rss.
2011. English. Split header, RSS.
sandstormnews.com 2011, SWF Arabic. ul.rss-items > li.rss-item, split header
zerosandonesnews.com 2011. SWF Split header, ul.rss-items > li.rss-item
lasthournews.com web.archive.org/web/20100513182623/http://lasthournews.com/. Urdu. JAR at: web.archive.org/web/20100513182724/http://lasthournews.com/recent.jar. Split header images.
mynepalnews.com, split header images, ul.rss-items > li.rss-item, Unarchived jar:
Mathieu group by Ciro Santilli 40 Updated 2025-07-16
Contains the first sporadic groups discovered by far: 11 and 12 in 1861, and 22, 23 and 24 in 1973. And therefore presumably the simplest! The next sporadic ones discovered were the Janko groups, only in 1965!
Each is a permutation group on elements. There isn't an obvious algorithmic relationship between and the actual group.
TODO initial motivation? Why did Mathieu care about k-transitive groups?
Their; k-transitive group properties seem to be the main characterization, according to Wikipedia:
Looking at the classification of k-transitive groups we see that the Mathieu groups are the only families of 4 and 5 transitive groups other than symmetric groups and alternating groups. 3-transitive is not as nice, so let's just say it is the stabilizer of and be done with it.
Video 1.
Mathieu group section of Why Do Sporadic Groups Exist? by Another Roof (2023)
. Source. Only discusses Mathieu group but is very good at that.
Lemma (mathematics) by Ciro Santilli 40 Updated 2025-07-16
A theorem that is not very important on its own, often an intermediate step to proving something that the author feels deserves the name "theorem".
Real projective plane by Ciro Santilli 40 Updated 2025-07-16
For some reason, Ciro Santilli is mildly obsessed with understanding and visualizing the real projective plane.
To see why this is called a plane, move he center of the sphere to , and project each line passing on the center of the sphere on the x-y plane. This works for all points of the sphere, except those at the equator . Those are the points at infinity. Note that there is one such point at infinity for each direction in the x-y plane.
Their status is a mess as of 2020s, with several systems ongoing. Long live the "original" collegiate university!
Lie algebra by Ciro Santilli 40 Updated 2025-07-16
Intuitively, a Lie algebra is a simpler object than a Lie group. Without any extra structure, groups can be very complicated non-linear objects. But a Lie algebra is just an algebra over a field, and one with a restricted bilinear map called the Lie bracket, that has to also be alternating and satisfy the Jacobi identity.
Another important way to think about Lie algebras, is as infinitesimal generators.
Because of the Lie group-Lie algebra correspondence, we know that there is almost a bijection between each Lie group and the corresponding Lie algebra. So it makes sense to try and study the algebra instead of the group itself whenever possible, to try and get insight and proofs in that simpler framework. This is the key reason why people study Lie algebras. One is philosophically reminded of how normal subgroups are a simpler representation of group homomorphisms.
To make things even simpler, because all vector spaces of the same dimension on a given field are isomorphic, the only things we need to specify a Lie group through a Lie algebra are:Note that the Lie bracket can look different under different basis of the Lie algebra however. This is shown for example at Physics from Symmetry by Jakob Schwichtenberg (2015) page 71 for the Lorentz group.
As mentioned at Lie Groups, Physics, and Geometry by Robert Gilmore (2008) Chapter 4 "Lie Algebras", taking the Lie algebra around the identity is mostly a convention, we could treat any other point, and things are more or less equivalent.
Quaternion by Ciro Santilli 40 Updated 2025-07-16
Kind of extends the complex numbers.
Some facts that make them stand out:
Dual space by Ciro Santilli 40 Updated 2025-07-16
The dual space of a vector space , sometimes denoted , is the vector space of all linear forms over with the obvious addition and scalar multiplication operations defined.
Since a linear form is completely determined by how it acts on a basis, and since for each basis element it is specified by a scalar, at least in finite dimension, the dimension of the dual space is the same as the , and so they are isomorphic because all vector spaces of the same dimension on a given field are isomorphic, and so the dual is quite a boring concept in the context of finite dimension.
One place where duals are different from the non-duals however is when dealing with tensors, because they transform differently than vectors from the base space .

Pinned article: Introduction to the OurBigBook Project

Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
We have two killer features:
  1. topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculus
    Articles of different users are sorted by upvote within each article page. This feature is a bit like:
    • a Wikipedia where each user can have their own version of each article
    • a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
    This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
    Figure 1.
    Screenshot of the "Derivative" topic page
    . View it live at: ourbigbook.com/go/topic/derivative
  2. local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:
    This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
    Figure 2.
    You can publish local OurBigBook lightweight markup files to either https://OurBigBook.com or as a static website
    .
    Figure 3.
    Visual Studio Code extension installation
    .
    Figure 4.
    Visual Studio Code extension tree navigation
    .
    Figure 5.
    Web editor
    . You can also edit articles on the Web editor without installing anything locally.
    Video 3.
    Edit locally and publish demo
    . Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.
    Video 4.
    OurBigBook Visual Studio Code extension editing and navigation demo
    . Source.
  3. https://raw.githubusercontent.com/ourbigbook/ourbigbook-media/master/feature/x/hilbert-space-arrow.png
  4. Infinitely deep tables of contents:
    Figure 6.
    Dynamic article tree with infinitely deep table of contents
    .
    Descendant pages can also show up as toplevel e.g.: ourbigbook.com/cirosantilli/chordate-subclade
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact