how do you know for sure the Earth isn't flat?

Answer 1

Really I don't know for sure. Just going by what I have been taught.

Answer 2

Because of a very simple piece of surveying.

You can't see beyond the horizon, beyond where the curve of the earth drops below the ground effect.

There are telescopes used to look at the moon, which is measured at a quarter of a million miles away. From new york to london is only about 1/100th of that distance, yet telescopes can't see london from new york, or new york from london. The horizontal straight across line of sight, keeps going straight, but the earth curves down away from it.

Columbus didn't prove that the earth was round, he just proved his measurements of the curve of the earth were wrong. He thought the earth was much smaller. He didn't realize that there were two continents and another ocean between Spain and the East Indies. Nobody circumnavigated the globe until almost 20 years after columbus died, so he never found out the real story anyway. But Cartographers (mapmakers) and other surveyors had already noticed the horizon and ground effects.

Answer 3

I know you have had a lot of wise-*** answers to this question, but it is the sign of an intelligent mind when someone questions what most people take for granted. Galileo, Copernicus, Newton and every other great scientific individual started-off by questioning the bland assumptions that the majority make.

However, I know for sure that the earth is not flat as I have flown in a plane and you can actually see the curve. It is quite a sight.

Answer 4

Actually, that hasn't been the question among educated people for millenia. Pythagorus, as early as 570 B.C.E., saw that the Earth is a sphere. They could tell this by the way the days were different lengths and at different times in different places across the world, and by the way certain constellations only appeared as you travelled farther north or south, along with a number of other reasons.

Answer 5

The planet earth can not be flat. There have been many photographs of the earth taken from space which reveal it to be spherical. Most of what we know about anything depends on taking somebody else's word for it.

Answer 6

Um maybe bec people have been outside of Earth. Been on the moon and seen the big ball in space lol.

Answer 7

YEAH..........how do we know the earth aint flat? Just because some fancy dancy scientist said so? If them scientists are so smart....how come they aint invented anything to make Rosie O'Donnel quit yappin' so much?

Answer 8

because if you look at the moon or the sun durning an eclipse then the shadow will be circular in shape.

Answer 9

Pictures from space.

Answer 10

I saw it from the moon.
And it's def. flat.