The host of the popular space show "Cosmos: A Spacetime Odyssey" gave a long list of facts that even a dummy can look at and conclude that the Earth is spherical in shape. Moving further in the video, he points out a joke about flat Earth believers who believe that all the planets, sun, moon and other celestial body is round except the Earth.
The flat earth society is composed of people who promote the idea that the earth is flat. If Earth were flat, sometimes you'd get a flat shadow. The sassy astrophysicist has managed to tick off flat-earthers by giving a thumbs down to their beliefs in the latest instalment of his YouTube show, StarTalk, owing the falseness and ridicule of it all to a bad education system, coupled with the very-well-used freedom of speech.
"For me, the fact that there's a rise of flat-Earthers is evidence of two things". And, two, we live in a country with a failed educational system.
"Our system needs to train you in not only what to know, but how to think about information and knowledge and evidence", Tyson says. "If we don't have that kind of training, you'd run around believing anything", Tyson said.
A lunar eclipse occurs when the earth is directly blocking the sunlight for the moon.
"If you see the shape of Earth's shadow on the moon, it is always round".
The first test involves watching a lunar eclipse. According to the astrophysicist, when a ship flows towards the horizon, its lower part seems to submerge under the water and this explains that the Earth is a spherical body. The easiest way is to see the many photos of the Earth taken from space, but there are ways to do it from the Earth's curved surface as well.
Finally, a bit more complicated and thorough test includes three wells at different locations. He also pointed out an ancient experiment conducted in 250 B.C.by Eratosthenes were he talked about two wells in two different cities. The direction of the incoming sunlight would hit the bottom only in one of the three wells. If a well is deep enough, it would only be possible to see the bottom of the well at noon when the sun is directly overhead - otherwise, the sunlight would be coming down at an angle that wouldn't reach the bottom of that well.