What is the primary proof earth isn't flat?

Question

I don't believe the earth is flat, but I cant prove it isn't, people says photos are doctored. what other proof can I offer stating the earth is not flat

Answer 1

There are no photos of the edge.

Answer 2

You can't offer ANY proof, actually, that earth is NOT Flat. Because it is. You'd be a lot better offering proof that the earth is Not a Globe/Ball. Its Not.

Answer 3

Spherical excess.
As the size of triangles increases, on Earth's surface, the sum of the three angles exceeds 180 degrees (with modern instruments, this is easy to detect). The amount of spherical excess is directly proportional to the area covered by the triangle, relative to the total area of the sphere. This is only possible on a finite, positively curved surface.
"Flat" triangles do not have spherical excess.
Even this was already understood by Greek geometers, over 2000 years ago.

Answer 4

Use Aristotle's three proofs. He sure didn't have photos available

Answer 5

my mother in law hasn't fallen off yet-we sent her on a cruise-she's back-now that's proof

Answer 6

People have navigated around the earth. Also it was written in the Bible that the earth was not flat years before navigation devices for ships.

Isaiah 40:22

Answer 7

Ways to see for yourself that the Earth is a sphere:

• Earth’s shadow on the Moon during a lunar eclipse
• Ships and the horizon – approaching ships appear as if they “emerge from the waves”
• Varying star constellations as you move toward or away from the equator
• Ride an aircraft - If you look out the window at high altitude, most of the time you can see the curvature of the earth at the horizon. You can also take many trips in the same direction and circle the globe.
• The existence of time zones
• Observe the direction of the pull of gravity from different locations.
• Images from space

Answer 8

Two thousand or more years ago even some ancient Greeks knew that the earth wasn't flat. As a ship goes away from port, the sails would disappear first. This was the first considered 'proof'. Another Greek thought he would attempt to find just how big the earth is. He erected a staff at noon and measured the length of its shadow. One year later, in another city north of the original, he did the same thing with the same staff. The shadows were no the same length, and with some geometry he figured out how big the earth is. He was wrong by about 10%, but that's not bad or ancient measurements. The noticed the shape of the shadow o the earth on the moon during an ellipse .. it was round. Sea going craft relied on the stars in the sky or navigation. As some went into the southern hemisphere they saw different stars and constellations. The north star was no longer visible. All these were proof that the earth is round.

Answer 9

Which city of earth is supposed to be at the edge?
Why can planes fly both ways?
What did Magellan's round-the-earth expedition do?

Answer 10

when you fly in a plane you can see that the earth is curved.