substack.michaelhartl.com
substack.michaelhartl.com is a live English-language website hosted on Cloudflare, Inc. (AS13335) in the United States, served by Cloudflare. cl0q first saw it on 2026-06-23 and last crawled it on 2026-06-30. It resolves to 172.67.167.89 and has mail (MX) records set up. Its favicon is fingerprinted by SHA-256, so you can find every other site that serves the same icon.
How the site describes itself:
Math, Physics, Tau, et alia | Michael Hartl | Substack
Mostly math and math learning. Posts include announcements related to Tau Day and The Tau Manifesto, as well as a variety of math topics and curated book and YouTube recommendations. Click to read Math, Physics, Tau, et alia, by Michael Hartl, a Substack publication with thousands of subscribers.
| Status | 200 OK — live & indexed by cl0q |
|---|---|
| First seen | 2026-06-23 |
| Last crawled | 2026-06-30 |
| IPv4 | 172.67.167.89 |
| IPv6 | 2606:4700:3031::6815:49de |
| Network | AS13335 Cloudflare, Inc. · California |
| Mail (MX) | aspmx.l.google.com,alt1.aspmx.l.google.com,alt2.aspmx.l.google.com,aspmx2.googlemail.com,aspmx3.googlemail.com |
| Language | en |
| Server | cloudflare |