Hacker News new | past | comments | ask | show | jobs | submit login
Cognicull: Knowledge base for mathematics, natural science and engineering (cognicull.com)
115 points by matsuu on April 29, 2021 | hide | past | favorite | 20 comments



The idea is interesting and the website is designed very nicely, but the subjects themselves are extremely lacking. For example the "level 22" Simple Harmonic wave is simply three graphs of a sine function with no other explanation. What is there to learn from that?


Some other knowledge-graph type projects for comparison:

> Metacademy - "Package Manager for Knowledge" - https://metacademy.org/

> MathLingua - language for easily creating a collection of mathematical knowledge, including definitions, theorems, axioms, and conjectures, in a format designed to be easy and fun to read and write. - https://www.mathlingua.org/

> Learn X in Y minutes - https://learnxinyminutes.com/

> Learn X by doing Y - https://aquadzn.github.io/learn-x-by-doing-y/

> Awesome Lists - https://github.com/sindresorhus/awesome

> ncatlab - https://ncatlab.org/ - I visit the page I want to understand and make sure I understand the meaning of most of the hyperlinks in the first paragraph before I attempt to understand the rest

Many people are also starting to use the bidirectional-link style of note-taking to create their own knowledge graphs. I'm curious to see what sort of tools will emerge in the future to help people share the graphs they've created.

It's easy enough to find reading lists online for a topic, but one of the hardest things about learning a new subject, especially without the help of a teacher, is learning what NOT to spend time on and why.


"Many people are also starting to use the bidirectional-link style of note-taking to create their own knowledge graphs. I'm curious to see what sort of tools will emerge in the future to help people share the graphs they've created." Roam research and clones...I started looking into that but I haven't setup anything yet. Would be keen to hear/read any testimonies


I use roamlikes as a combined bookmark / note-taking system.

I tend to spend a few minutes every day taking some interesting links from HN or elsewhere (that I may or may not read that day) and creating entries for them in my personal wiki system.

(This is how I keep track of collections of related links -- for my post above, I just searched for [[knowledge-graph]] tags in my wiki system and copied the results into an HN comment)

I find this most useful for topics that I know I'd like to explore in the future, but just don't have time for right now. The Google search signal-to-noise ratio has lessened so much that I know I'll never be able to find a specific link again unless I remember the exact title, so it's useful to have a way to quickly assign tags to a URL and forget about it until later. Tagging systems are much better than a hierarchical bookmark system for recall later [1].

Then, when I take the time to read about a certain topic, I start taking notes in the .md file corresponding to the appropriate keyword or citation.

The best part is discovering new connections between topics -- sometimes I'll type a [[keyword]] in my notes, and see that several of my existing notes already link to it.

I'm still learning how to best use a system like this, it does take some effort to maintain. Right now what works for me is really short, concise notes about very specific keywords to start. Then I'll do a "synthesis" pass where I'll summarize the relationships between several keywords all in one document, and then make all the keyword nodes in the graph point to the synthesized document instead.

[1] Nayuki, "Designing Better File Organization around Tags, Not Hierarchies" -- https://www.nayuki.io/page/designing-better-file-organizatio...


I use roam myself. Mind sharing the alternative(s) you use and find most useful? Would be interested in learning what roamlikes others prefer and why.


I use my own not-yet-ready-for-release app called Noteworthy [1], but here is a list of some of the roamlikes I find most inspiring:

> Athens Research -- free and open source roam competitor made by someone who failed an interview for a job at roam :) -- https://github.com/athensresearch/athens

> Obsidian -- free but non-open wikilink system based on Markdown files -- https://obsidian.md/

> Foam -- Markdown-based knowledge management system based entirely around VS Code extensions -- https://foambubble.github.io/foam/

> Neuron/Cerveau -- Markdown-based Zettelkasten and static site generator written in Haskell -- https://neuron.zettel.page/

Some other honorable mentions that I can't be bothered to dig up links for: Madoko, RemNote, Notion, TiddlyWiki, Cerveau, Zettlr, Notable

[1] https://github.com/benrbray/noteworthy


Awesome, thanks so much!


Thanks a lot - this thing is great! https://ncatlab.org/nlab/show/Gravity+and+Grace


This looks good. For me the name recalls "cull" as in

verb 1. reduce the population of (a wild animal) by selective slaughter. "he sees culling deer as a necessity" Similar: slaughter kill destroy reduce the numbers of thin out the population of 2. select from a large quantity; obtain from a variety of sources. "anecdotes culled from Greek and Roman history" Similar: select choose pick take obtain get glean

noun a selective slaughter of animals. "fishermen are to campaign for a seal cull"

I guess it may be too late to change the name now, but some suggestions:

cognical (nearly the same sound, but no connotation of slaughter, for me anyway)

cognizul (not really sure, just a random one)

cogniqul (not sure, just random one)


Neat and smooth GUI indeed, but like the other commenters I am not impressed by the contents.

The animated graph for instance in https://cognicull.com/en/8e2konlv that shows "If the width of the change stepwise in the time direction is narrowed as follows, it will be a very smooth curve. You can't see the change stepwise, but the last smooth curve is also a digital signal."

-> their bit depth is ALSO changing in their animated picture. So even if the text that follows further addresses that - they are completely missing the point of a good explanation with their illustration.


Very nice website, but it would be tremendous undertaking to create content under all the topics. I would imagine another possible approach is to provide a short summary and a link to Wikipedia (or other sites) for detailed content. Presenting knowledge as a tree / web is always an attractive idea to me.


This is a good concept. Identifying what skills the student may lack if the lesson is difficult is a really good idea. It is missing from too many books in which the author just assume a student will be able to identify what he or she should learn to understand a specific topic.


Spent some time on this today, it's very close to how I think in general, and the "if you don't get this, you may need this, and this" is absolutely amazing.

There is a breadth first way of learning that this site enables, and for applying math concepts in code, this is way more efficient than wikipedia. Like if I want to learn to use the numpy fft package because I want to do something to an audio file, as a non-engineer, I'd use cognicull's FFT example to learn enough about the concepts to be able to use the library features.


Very nice! I appreciate also the multilingualism.

However, would it be possible to add an easy way to change language from the page of an article?

Right now to do that, I need to lookup the translation of the title and go back to the summary, which is not convenient.


Well designed interface. There might be something here if one can use this to render one's own notes? Or is this meant to render user provided content like Wikipedia?


Pretty nice, I liked it.

A dark mode would be ideal.


There is dark mode, you can toggle it in the upper left corner.


I see it now. It goes away once you click a concept.


If you want to learn what's on the site a the first semester of university maths would be a good choice.


I don't understand the purpose, or rather, the comparative advantage of this website. It looks like a series of topics covered in the first few lectures of an undergraduate course in Fourier analysis (plus a few other topics). So why not just read a well-written Fourier analysis textbook? There's no motivation or coherence to this project, as far as I can see, just a collection of terse notes.




Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: