So you can go in a circle around a globe, guided by the magnetic north,

Yes

but not on a flat plain?

There is no such thing as a flat plane (referencing shape of the earth)

Because Magnetic declination... And you can go around the North pole itself?

If you are at the equator, yes, you can fly around the earth constantly adjusting for magnetic declaration, yes. However, today, we use GPS in airplanes making it much easier.

But again you can't do this on a flat plain because of "Magnetic declination"?

There is no evidence of a flat plane. None.

You can't grasp the concept that the stars should not be displayed on a flat map,

Stars are in outer space. Why would they appear on a map of the earth?

while the Earth is a globe?

Yes, it is.

You think flat is the opposite of round?

Uh, yeah, I guess, what is it for you?

You don't know the difference between Earth with a capital letter, and earth as the ground?

Grammer nazi?

You can picture standing on a globe, but not visualize the flat ground under your feet, while looking directly at a manufacture floor.

The ground is not flat, over the span of thousands of miles, it eventually curves. What is "manufacture floor" - I have one in my kitchen, is that what you mean?

That was the Question by the way.

What?

You state repeated information as facts without analysis of any kind,

I repeat known facts, that is true. What are you doing? Repeating baseless conspiraices?

simply assuming you were told the truth

I see the truth with my own eyes. I do not need to be convinced via Youtube which seems to be what happened to you.

and therefore provide that information as evidence and facts.

I read, observe and make calculated decisions on empirical evidence. You do not do this, otherwise you would know the earth is a ball.

You speak of the iron core of the Earth, yet can not fathom what the Black Sun could be.

Correct. what is it? Have you seen it with your own eyes? Has any peer-review paper suggested this is true? has the scientific community supported such an idea? Molten iron, on the other hand, can be explained and is supported by thousands of scientists who believe the massive pressure and our magnetic van allen belts is keeping us alive from cosmic radiation is 100% plausible. While nothing is 100% since no one has ever seen the core, empirical evidence suggests it is true.

And again, there is no credible evidence that when you look at your own feet, that the small space you occupy is flat?

A 1x1 square can be flat. It can be perfectly flat because it only covers a small area. But if you take that 1x1 square, and expand it outwards a few thousand miles, gravity will pull it towards the center every time. If it were to remain perfectly flat over thousands of miles, you would need to elevate it. This is why suspension bridge towers are never 100% parallel. If you took an engineering course, you would learn that you need to compensate for the curvature of the earth. Go ask an engineer. They will confirm.

Which ties back into your lack of an ability to understand terms such as flat and round are relative, and not opposite concepts.

Semantics is a bitch.