I goof on the flatearthers but it's really deeply saddening that people can't do basic critical thinking and have taken refuge in this "I guess we'll just never know" attitude.
it's true there are people lying to you. this just means you have to take responsibility for figuring things out yourself.
go out and look at the night sky and wonder why it revolves around a central axis, fly to Australia and see how the stars look there ffs.

you can know. if you learn to think and wonder about the world, knowledge comes of itself.
people were measuring gravitational forces in the 17th century, you can do it too.