When you have only one, it’s PHENOMENON!
Here’s the goof, by someone who ought to know better.
Although the ideas have persisted for generations, the modern Flat Earth phenomena is surprisingly recent.
This is from The Guardian, a British newspaper. If anybody ought to get their Latin plurals right, it’s the Brits! Harrumpf.
The article, except for this error, of course, is kind of a fun read. Flat Earthers say this photo is fake: