The idea of a flat earth is not a recent idea; that's not what the "myth of the flat earth" is. The myth of the flat earth refers to the false idea that (educated) Europeans during the Middle Ages believed in a flat earth, or that the ancient Greeks did, etc.

But plenty of other people believed in a flat earth, both back then and in more recent times. Ancient Mesopotamian astronomy, for instance, used a flat earth model. More astonishingly, Chinese astronomers used a flat earth model until the 16th century.

> Ancient Mesopotamian astronomy, for instance, used a flat earth model. More astonishingly, Chinese astronomers used a flat earth model until the 16th century.

This is hardly a proof these astronomers did believe their model pictured the shape of the Earth correctly. In fact, a kind of flat Earth model and a (horizontal coordinate system)[https://en.wikipedia.org/wiki/Horizontal_coordinate_system) is used to this day in astronomy to demonstrate how the sky and the celestial bodies appear to an observer on the ground. This was exactly the purpose of earlier astronomers because from this knowledge they could deduce predictions about the seasons and eclipses (and, ok, lucky and unlucky days and so on). If you're ready to deal with a modicum of epicycles and are only interested in purely local ephemerides, the model is actually not so bad as a framework for calculations and the real improvement only comes with a heliocentric model with elliptical orbits, not so much from a spherical Earth.

What is causing the most recent flat earth theory outbreaks all over the world? Could it be some environmental factor like pollutants, IQ is declining, bs online is increasing. Somehow it has to be the ultimate conspiracy theory measured by outlandishness.

> Ancient Mesopotamian astronomy, for instance, used a flat earth model.

I mean, we do too, we just call them 2D projections, but they are "flat earth models" :^)

Yes I know I gave talks on the topic for some time.