If you're really interested in the topic, you'd have to do more research & deploy some critical thinking, not just have blind faith in a puppet called NDT.
https://steemit.com/flatearth/@switzerflatland/the-very-basics-flat-earth-101
https://steemit.com/science/@switzerflatland/the-reality-of-the-fake-globe-fact-no-1
https://steemit.com/science/@switzerflatland/the-reality-of-the-fake-globe-fact-no-2
https://steemit.com/science/@switzerflatland/the-reality-of-the-fake-globe-fact-no-3
https://steemit.com/space/@switzerflatland/the-reality-of-the-fake-globe-fact-no-4
https://steemit.com/flatearth/@switzerflatland/the-reality-of-the-fake-globe-fact-no-5
https://steemit.com/flatearth/@switzerflatland/the-reality-of-the-fake-globe-fact-no-6