First of all, it's not a theory. "A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment. Such fact-supported theories are not "guesses" but reliable accounts of the real world." Flat-earthers are simply crackpots.

Guys like this started it!

If it wasn't for Utube the 'flat earth' cult would be a non event and the followers of this cult would be no bodies.

I mean let's just start by saying that the earth is certainly not flat. I visited the flat earth convention in the UK this year out if morbid curiosity and basically every presentation had some form of religious sub text... I wouldn't doubt that faith is the true guiding principle of flat earth theory.

"some of the measurements and experiments to proof the theory" Much of science relies on what is called "falsification", or in other words disproof of ideas. Flat-earthers need to also be looking into what would disprove their theory, if they are to do honest science.

When we look at the earth and its' place in the universe, we quickly see numerous disproofs. From the spherical shadow of the earth on the moon, to the measurable curvature of the earth, to the actual pictures from satellites (which in a relatively uncommon situation for science should be sufficient proof of a ball earth), to the orbits of satellites themselves. That's only the direct stuff. Then there is how gravity works in 3D space, how matter deforms under forces to form a ball, and how all planets are most likely to parallel each other, so if Earth is a planet of similar size as Venus, it should be a ball like Venus is if it is composed of similar materials.

What you need is a small row boat and start rowing in the same direction for months or perhaps years depending how strong you are, and then you will find your answer. You either fall off or you get back to where you started or the sharks will get you.

Every bit of scientific evidence supports that the earth is round, just like every other planet in the cosmos.

The earth's shadow on the moon during a lunar eclipse is ROUND. A ship sailing away from you disappears slowly as it goes sailing away. The mast being the last to sink beneath the horizon. these are just 2 ways that a casual observer can prove that the earth is round. Also there are many photos of the earth from space from all different directions and they all show a round planet. Or don't you believe in our orbiting spacecraft either?