You may have heard of the kid who told his teacher that the equator was "an imaginary lion running around the Earth".
As far as imaginary lines are concerned, a famous system was invented by the French mathematician and philosopher René Descartes. He suggested that a flat surface could be crisscrossed by a set of evenly-spaced vertical and horizontal lines, enabling us to indicate the exact location of any point on the surface by a pair of so-called Cartesian coordinates.
Before the time of Descartes, geographic coordinate systems had been applied to the surface of the globe, materialized by circles of latitude and longitude forming a grid.
The Flemish cartographer Gerardus Mercator [1512-1594] had even invented a handy trick for projecting these circles onto the surface of a cylinder, which could then be flattened out to give the illusion that the surface of our globe could be thought of as a big rectangle. And all that remained was for perspicacious Australians, located at the center of the world, to point out the sense in which this rectangle is to be viewed.
Now why—you might be wondering—have I got carried away with this pedantic talk about coordinate systems? Well, it appears that some people are even dumber than the above-mentioned school kid, because they seem to forget that a grid enclosing the globe is necessarily an abstract entity, which might be described as virtual, rather than a material structure on which you might bump your head. That aspect of the global grid would seem to be so obvious that it's hardly necessary to mention it… were it not for the fact that, some fifty years ago, a German physician named Ernst Hartmann posited the existence of a real grid, above our heads, composed of "naturally-occurring charged lines, running North-South and East-West". Today, naturopaths (individuals who believe in alternative systems of medicine) speak of the invisible Hartmann Net, and they are prepared to indicate the exact dimensions of this grid. I don't intend to pursue this subject in greater depth… for the simple reason that I have no idea whatsoever of what the hell these naturopaths are talking about.
I'm not sure why I seem to be targeted as a possible patient by a few French naturopaths. I once built an aviation-oriented website for a fellow who now works as a naturopath, and I created another website in an attempt to sell the ancient house in the village of St-Antoine belonging to a female naturopath. Those could well be the associations that led to my receiving a spam email this morning from a French naturopath who has apparently been operating in the small Swiss city of Yverdon-les-Bains, at the southern extremity of Lake Neuchâtel.
It so happens that Yverdon has a fascinating tourist attraction: a park of 45 prehistoric standing-stones, known as menhirs in French. Well, I'll let you imagine the excitement of our naturopath when he dishes up an exotic salad whose ingredients are the Hartmann Net at Yverdon and the "geobiological" effects of the standing-stones. Apparently, some of the menhirs happen to be located at "geopathogenic nodes" of the Hartmann grid, whereas others stand at "positive Hartmann nodes". Now, don't forget that the alleged goal of all this tripe is to provide patients with health treatment.
Funnily enough, the naturopath forgot to mention the origin of these menhirs. They were dragged there by a legendary beast, in the remote past, and installed at precise points on the Hartmann grid. Dragged there by what archaic animal, you ask? By the imaginary lion that spends its time running around the globe...