Please climb into Cantor’s attic, where you will find infinities of all sizes. The site aims to be a comprehensive resource for the mathematical logic community, containing information about all mathematical concepts of infinity, including especially detailed information about the large cardinal hierarchy, as well as information about all other prominent specific ordinals and cardinals in mathematical logic and set theory, and how they are related. We aim that Cantor’s attic will be the definitive on-line home of these various notions. Please link to us whenever you need to link to a large cardinal or ordinal concept.

Cantor’s attic is the result of a community effort, and you can help improve this resource by joining our community. We welcome contributions from knowledgeable experts in mathematical logic. Please come and make a contribution! You can create new pages, edit existing pages, add references, all using the same mediawiki software that powers wikipedia. Further information about how to help is available at the Cantor’s attic community portal.

Cantor’s attic was founded in December 2011 by myself and Victoria Gitman. We have only just begun, and it is a good time to get involved. Feel free to contact me for advice or specific suggestions about how you might contribute.

Cantor would be proud. This site is set theory at its finest.

I can’t climb into the attic due to the 403 error and it seems others experience the same problem since at least December 18, 2012.

Yes, we will fix this problem very soon.

Mr. Hamkins, I can’t get to the site since November. I see only the “Internal Error” page. Other users around the world have the same problem. The site is excellent and it’s a pity that it is not working at present.

Mr. Hamkins, I also can’t get to the site. Is there any trouble need help? Cantor’s attic is a excellent place to learn about set theory.

Has this project been discontinued, moved or something else? I’m still interested in the site. Thank you!

It hasn’t been discontinued; its just that I’ve been too busy to give it the time it needs.

Aw 🙁 that’s sad to hear.

If anyone’s looking for a static archive, most (all?) of the site seems to be on the Wayback Machine, and the MathJax rendering works: http://web.archive.org/web/20191104130451/http://cantorsattic.info:80/Cantor%27s_Attic

Would you please fix the site soon? This is such a good place to learn about large cardinals and set theory, and without it I would have to search through the whole Internet to find what I need. Thanks!

Hello. Would you be interested in a version of the attic that does not need any database, nor any server, instead built statically and served through modern CDN tech? If that is the case, I will be glad to help setting it up.

Thanks for the offer. I am overwhelmed, and unfortunately haven’t been able to give it attention. I need to consider how to proceed in a way that doesn’t rely on me being in charge of any system.

My idea is to get the content down from archive.org, produce markdown files from it, upload them to a github repository (public) and add enough code to make it into a static site (served by netlify for instance).

Instead of relying on a live database, content updates would rely on git pull requests, that would be done on said repository.

I am willing to do the work and show you the results, of course then you can decide whether to collaborate, block or any other action.

work in progress at https://github.com/neugierde/cantors-attic (rendered: https://neugierde.github.io/cantors-attic/docs/). A lot of the formatting is gone, and I still have to add mathjax or something similar.

Feel free to give me feedback directly on github.

For anyone interested, I have set up a kind of a static mirror at https://neugierde.github.io/cantors-attic/

Contributions are welcome