What evidence is there that the earth is spherical or shaped like a ball?

Question

Hi im in The Bahamas and i need this for my grade 11 geography class.

Answer 1

1. The shadow it casts on the moon during an eclipse
2. The fact that you see an approaching ship's mast prior to the rest of the ship as it emerges over the horizon.
3. Measuring the height from the horizon of a tall structure from three different locations, fixed at 12:00, 4:00, and 8:00 will reveal that if you are the same distance from the tall object, the height will appear to be the same from all three locations. This would only happen if the world were round.

Answer 2

Egyptian mathematicians first measured the diameter of the earth about 5,000 years ago, by observing the differences in the angles of shadows cast in deep wells at different locations at the same time of day.

There are numerous geometric solutions that show that the earth's diameter can be measured the same in all directions, indicating a spherical shape. Some of those ideas have been described in other answers.

In today's scientific environment, there can be no question about it, as high flying aircraft have been observing the curve of the horizon, which becomes noticeable at about 45,000 feet, since about the 1930s. Now countless photographs of the earth from space show that our home is a blue marble.

And, of course, there is the fact that the earth casts a round shadow on the moon during an eclipse. That has also been observed for hundreds of years.

So those are some of the ways we know. You can't fall off the edge.

Answer 3

How about pictures from space? Looks round to me, and I didn't calculate anything.

Answer 4

So you think the world is square look at the maps its round

Answer 5

Everyone knows the earth is flat!

Answer 6

the most obvious evidence, is the whole ship dissappearing over the horizon thing. its quoted all the time as the example of the earth being not flat.
gimme 10 points please please?

Answer 7

by copernicus' theory

Answer 8

We have seen it.