Flat Earth: Day and Night
The most basic thing we experience is the sun rising in the morning and setting in the evening. The times for sunrise and sunset at all locations on earth are known very accurately and can be predicted very accurately also by the globe earth model. But the flat earth people are unable to present a model that can produce the sunrise and sunset times that we practically experience on the planet.
Flat Earthers Need to Present a Model that Works!
If flat earthers expect to be taken seriously by thoughtful people and scientists they have to present a model based on the assumption the earth is flat that ACTUALLY WORKS!
A very good example of such a working, valid scientific predictive model is the globe earth model we are all very familiar with.
To be taken seriously flat earthers have to present a model that is at least as good as predicting the things we observe happening around us and in the sky as the globe earth model does.