Polar circumnavigation is complete navigation around Earth through both the North Pole and the South Pole. Several parties have successfully done it, and it is only possible if Earth is a sphere.
Flat-Earthers incorrectly claim that Earth circumnavigation has never been done through both the poles, and they use it to “prove” a flat Earth. In reality, many have successfully done such feats.
Continue reading “Polar Circumnavigation”
Many sports involve launching balls into the air. Launched balls are projectiles and will be deflected by a tiny amount due to the Coriolis effect from Earth’s rotation.
Athletes never account for the Coriolis effect, and flat-Earthers use it to “disprove” Earth’s rotation. In reality, the deflection from the Coriolis effect in sports is very tiny. It does not mean the Coriolis effect does not exist.
Continue reading “Coriolis Effect in Sports”
We can determine if a star is visible from a specific location using the declination of the star and the latitude of the observer, subject to other conditions like observer’s topology, the magnitude of the star, weather conditions, etc. It is possible to do this because Earth is a rotating sphere.
If the Earth is flat, every star would have been visible all night from every location. We don’t see the same stars every night because some of them are below the horizon and obscured by the Earth.
Continue reading “Determining the Visibility of a Star From Its Declination and the Observer’s Latitude”
A circumpolar star is a star, as viewed from a given latitude on Earth, that never sets below the horizon due to its apparent proximity to one of the celestial poles. Circumpolar stars stay up there in the sky, even during the day.
Flat-Earthers claim the Earth is stationary because the same stars are always visible in the sky. They are wrong. Only circumpolar stars are always in the sky. There are others that are not circumpolar. Some are only visible during certain times in a year.
Continue reading “Circumpolar and Non-Circumpolar Stars”