So far, no new domains have been found with Common Crawl, nor have any existing known domains been found to be present in Common Crawl. Our working theory is that Common Crawl never reached the domains How did Alexa find the domains?
Let's try and do something with Common Crawl.
Unfortunately there's no IP data apparently: github.com/commoncrawl/cc-index-table/issues/30, so let's focus on the URLs.
Hello world:
select * from "ccindex"."ccindex" limit 100;
Data scanned: 11.75 MB
Sample first output line:
#                            2
url_surtkey                  org,whwheelers)/robots.txt
url                          https://whwheelers.org/robots.txt
url_host_name                whwheelers.org
url_host_tld                 org
url_host_2nd_last_part       whwheelers
url_host_3rd_last_part
url_host_4th_last_part
url_host_5th_last_part
url_host_registry_suffix     org
url_host_registered_domain   whwheelers.org
url_host_private_suffix      org
url_host_private_domain      whwheelers.org
url_host_name_reversed
url_protocol                 https
url_port
url_path                     /robots.txt
url_query
fetch_time                   2021-06-22 16:36:50.000
fetch_status                 301
fetch_redirect               https://www.whwheelers.org/robots.txt
content_digest               3I42H3S6NNFQ2MSVX7XZKYAYSCX5QBYJ
content_mime_type            text/html
content_mime_detected        text/html
content_charset
content_languages
content_truncated
warc_filename                crawl-data/CC-MAIN-2021-25/segments/1623488519183.85/robotstxt/CC-MAIN-20210622155328-20210622185328-00312.warc.gz
warc_record_offset           1854030
warc_record_length           639
warc_segment                 1623488519183.85
crawl                        CC-MAIN-2021-25
subset                       robotstxt
So url_host_3rd_last_part might be a winner for CGI comms fingerprinting!
Naive one for one index:
select * from "ccindex"."ccindex" where url_host_registered_domain = 'conquermstoday.com' limit 100;
have no results... data scanned: 5.73 GB
Let's see if they have any of the domain hits. Let's also restrict by date to try and reduce the data scanned:
select * from "ccindex"."ccindex" where
  fetch_time < TIMESTAMP '2014-01-01 00:00:00' AND
  url_host_registered_domain IN (
   'activegaminginfo.com',
   'altworldnews.com',
   ...
   'topbillingsite.com',
   'worldwildlifeadventure.com'
 )
Humm, data scanned: 60.59 GB and no hits... weird.
Sanity check:
select * from "ccindex"."ccindex" WHERE
  crawl = 'CC-MAIN-2013-20' AND
  subset = 'warc' AND
  url_host_registered_domain IN (
   'google.com',
   'amazon.com'
 )
has a bunch of hits of course. Data scanned: 212.88 MB, WHERE crawl and subset are a must! Should have read the article first.
Let's widen a bit more:
select * from "ccindex"."ccindex" WHERE
  crawl IN (
    'CC-MAIN-2013-20',
    'CC-MAIN-2013-48',
    'CC-MAIN-2014-10'
  ) AND
  subset = 'warc' AND
  url_host_registered_domain IN (
    'activegaminginfo.com',
    'altworldnews.com',
    ...
    'worldnewsandent.com',
    'worldwildlifeadventure.com'
 )
Still nothing found... they don't seem to have any of the URLs of interest?
Last mile problem by Ciro Santilli 40 Updated 2025-07-16
The exact same problem appears over and over, e.g.:
Ciro Santilli also identified knowledge version of this problem: the missing link between basic and advanced.
activatedgeek/LeNet-5 by Ciro Santilli 40 Updated 2025-07-16
This repository contains a very clean minimal PyTorch implementation of LeNet-5 for MNIST.
It trains the LeNet-5 neural network on the MNIST dataset from scratch, and afterwards you can give it newly hand-written digits 0 to 9 and it will hopefully recognize the digit for you.
Ciro Santilli created a small fork of this repo at lenet adding better automation for:
Install on Ubuntu 24.10 with:
sudo apt install protobuf-compiler
git clone https://github.com/activatedgeek/LeNet-5
cd LeNet-5
git checkout 95b55a838f9d90536fd3b303cede12cf8b5da47f
virtualenv -p python3 .venv
. .venv/bin/activate
pip install \
  Pillow==6.2.0 \
  numpy==1.24.2 \
  onnx==1.13.1 \
  torch==2.0.0 \
  torchvision==0.15.1 \
  visdom==0.2.4 \
;
We use our own pip install because their requirements.txt uses >= instead of == making it random if things will work or not.
On Ubuntu 22.10 it was instead:
pip install
  Pillow==6.2.0 \
  numpy==1.26.4 \
  onnx==1.17.0 torch==2.6.0 \
  torchvision==0.21.0 \
  visdom==0.2.4 \
;
Then run with:
python run.py
This script:
  • does a fixed 15 epochs on the training data
  • it then uses the trained net from memory to check accuracy with the test data
  • then it also produces a lenet.onnx ONNX file which contains the trained network, nice!
It throws a billion exceptions because we didn't start the Visdom server, but everything works nevertheless, we just don't get a visualization of the training.
The terminal outputs lines such as:
Train - Epoch 1, Batch: 0, Loss: 2.311587
Train - Epoch 1, Batch: 10, Loss: 2.067062
Train - Epoch 1, Batch: 20, Loss: 0.959845
...
Train - Epoch 1, Batch: 230, Loss: 0.071796
Test Avg. Loss: 0.000112, Accuracy: 0.967500
...
Train - Epoch 15, Batch: 230, Loss: 0.010040
Test Avg. Loss: 0.000038, Accuracy: 0.989300
And the runtime on Ubuntu 22.10, P51 was:
real    2m10.262s
user    11m9.771s
sys     0m26.368s
One of the benefits of the ONNX output is that we can nicely visualize the neural network on Netron:
Figure 1.
Netron visualization of the activatedgeek/LeNet-5 ONNX output
. From this we can see the bifurcation on the computational graph as done in the code at:
output = self.c1(img)
x = self.c2_1(output)
output = self.c2_2(output)
output += x
output = self.c3(output)
This doesn't seem to conform to the original LeNet-5 however?
Lecture notes:
Video 1.
How the 2D FFT works by Mike X Cohen (2017)
Source. Animations showing how the 2D Fourier transform looks like for simple inpuf functions.
Deep learning by Ciro Santilli 40 Updated 2025-07-16
Deep learning is the name artificial neural networks basically converged to in the 2010s/2020s.
It is a bit of an unfortunate as it suggests something like "deep understanding" and even reminds one of AGI, which it almost certainly will not attain on its own. But at least it sounds good.
BB84 by Ciro Santilli 40 Updated 2025-07-16
Does not require entangled particles, unlike E91 which does.
en.wikipedia.org/w/index.php?title=Quantum_key_distribution&oldid=1079513227#BB84_protocol:_Charles_H._Bennett_and_Gilles_Brassard_(1984) explains it well. Basically:
  • Alice and Bob randomly select a measurement basis of either 90 degrees and 45 degrees for each photon
  • Alice measures each photon. There are two possible results to either measurement basis: parallel or perpendicular, representing values 0 or 1. TODO understand better: weren't the possible results supposed to be pass or non-pass? She writes down the results, and sends the (now collapsed) photons forward to Bob.
  • Bob measures the photons and writes down the results
  • Alice and Bob communicate to one another their randomly chosen measurement bases over the unencrypted classic channel.
    This channel must be authenticated to prevent man-in-the-middle. The only way to do this authentication that makes sense is to use a pre-shared key to create message authentication codes. Using public-key cryptography for a digital signature would be pointless, since the only advantage of QKD is to avoid using public-key cryptography in the first place.
  • they drop all photons for which they picked different basis. The measurements of those which were in the same basis are the key. Because they are in the same basis, their results must always be the same in an ideal system.
  • if there is an eavesdropper on the line, the results of measurements on the same basis can differ.
    Unfortunately, this can also happen due to imperfections in the system.
    Alice and Bob must decide what level of error is above the system's imperfections and implies that an attacker is listening.
Backpropagation by Ciro Santilli 40 Updated 2025-07-16
Video 1.
What is backpropagation really doing? by 3Blue1Brown (2017)
Source. Good hand-wave intuition, but does not describe the exact algorithm.

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