Can you help me brainstorm some events that are supposed to happen on a predictable regular cycle, several years apart? In addition to:

* Leap year happens every 4 years. (US Presidential elections are in leap years.)
* You're supposed to get a tetanus booster shot every 10 years.
* Periodical cicadas emerge every 17 years.
* Halley's comet returns every 74 to 79 years.

This is for a project that I'm working on. What other cycles like this can you think of?


@frameacloud I think sunspots happen every eleven years. Need to check that with a solar scientist, though..

· · Web · 0 · 0 · 0
Sign in to participate in the conversation

The social network of the future: No ads, no corporate surveillance, ethical design, and decentralization! Own your data with Mastodon!