what is the best method of observing curvature of earth?

I shouldn't answer this, this is top secret CIA information but if you walk to the top of the world, the North Pole carefully estimating your position by compass, ruler and pencil and paper.

Then live for a month there off the land examing your landscape.

Then walk south carefully counting your footsteps as you go examining only one side usually west since most are right handed, you will see the flat plane of the flat Earth we live on..never look east!

And when you discuss it you will swear all rumors of a round Earth completely fake. Without a doubt.

If you observe a large smooth body of water with a good pair of binoculars, you can see the curvature of the surface.

Nfjdei

The easiest is to watch a ship move over the horizon ... If earth is flat a ship would simply get smaller and smaller ..but you would see the entire ship from waterline to top of mast

What really happens is the bottom of the ship drops out of sight completly. The only part visible at one hundred to 200 miles is the highest poiint

This can only happen on a curved surface

HOT AIR BALLOON!

Coriolis effect is also a good way of observing this.

If you know someone who lives directly north or south of you, call him and tell him to put a vertical stick in the ground on a sunny day and measure the length of the stick and its shadow. . You do the same with the same length stick at the same time. The difference in shadow lengths indicates the earth's curvature. You can even calculate its radius.

The higher the better

Or if you live beside the sea like me

You can watch ships sailing over the horizon, which is actually 11 miles away

the last thing to disappear is their funnel

You can ask yourself, why does the Ocean curve when it is water ??

We used to climb a desert mountain in southern New Mexico. Just a huge rock jutting up. Easy climb and we'd sit on a cliff edge way up there and watch the world. We could see 50 miles at least. And the curvature of the Earth was obvious. Not something everyone has near their house, no.

Observing the curved shadow of the Earth when cast upon the Moon during a Lunar eclipse is one of the best ways.

Standing at the edge of the ocean and watching ships disappear at the horizon - bottom of the ships disappear first as they go over the curvature of the earth.