[devils advocate]

So I'm stood on a beach looking out to a calm sea with the horizon visible for many miles each side of me. The horizon is about 3 miles in front of me. From in front of me a boat sails away towards the horizon and then vanishes 'over' it, bottom first. RE tells me that is proof of the curve of the earth that I am witnessing.

However.......the horizon is visible for well over three miles each way to my left and right also so why can I not see evidence of the curve in either of those directions? If the curve is great enough to hide a ship 3 miles to my front would I not expect to "see" the curve laterally also?

[Hmmm]

devils advocate, do you know where this beach is according to Google, Bing maps, and where is the north and south? It's important to know the geolocation of the beach itself too.

[douglips]

I was just doing the math on this in response to the statement "The horizon is always at your eye level" statement on the wiki. The only way to see the curvature would be if the horizon is perceptibly lower than eye level, refuting a key tenet of FET.

In RET the horizon is always slightly below eye level. I.e. if the tangent to the surface where you are standing is at 0 degrees, the horizon is at about 0.04 degrees below that tangent plane. Not enough to measure.

But, if you go up to 5000 feet, it's 1.25 degrees below, and at 10000 feet, 1.77 degrees. In an airliner at 40000 feet, it would be 3.5 degrees below the tangent plane.

From a mountain top it should be possible to build a rig to measure 1 degree of additional sky above the horizon, but I don't think you could see it with your naked eye. From low altitude, there's no way you could perceive it.

Here's the calculation: https://www.google.com/search?q=arccos%283%2C959+mi+%2F+%283959+mi+%2B+40000+feet%29%29+in+degrees

[devils advocate]

Brull thanks douglips that does make sense. Cheers Hmmm I was just thinking figuratively rather than a specific location which I should have States, thanks for your response :-)