Wolfgang Korsus Dipl.-Ing.NT, Astrophysiker
Website : wolfgang.korsus.net
That was the edge of the earth
B This was probably the most terrible danger for seafarers in the distant past. So what was threatening here was a mortal danger.
A numerically large number of seafarers never came back from their journey and so mothers and women cried at that time for their sons, husbands and brothers.
I could read it in many literature testimonies what the population living at that time gave so verbally from itself and have one of the most deeply going sayings mai pointed out ….
For in the wide sea the salt, these are the tears of Portugal ,
…a very thought-provoking saying and yet true… they are thoughts of a great Portuguese poet, namely – Fernando Pessoa.
The dangers that lurked on seafarers of that time can also be depicted in a simpler way. They still exist today. Some of them are still there today, rocks that are difficult to see, storms, giant waves and „sea snakes, octopuses and other terrifying sea monsters“- but far surpassing all such terrors was the thought that at the edge of the earth, i.e. the imaginary disk of the earth, one would simply fall down and disappear into nothingness…….
no grave, without cross, without, that was at that time certainly the most terrible without a blessing of the beloved church, yes this „blessed blessing of the so wise church“.
Dear mature readers, I certainly do not exaggerate ! But such a nonsense was effectively beaten into the people living at that time from infancy. Because somewhere the world (the earth disk) had to stop finally, and for this reason one should rather not sail so far.
,,,and how not differently conceivable, one gave this end of the world also a swinging name, the time amounted so around 1400 A.D. :
…..and this name developed quickly and quite simply, it was the Cape Bojador, a point, or better a geographical place …..namely a western tip of the continent of Africa. We know this today, but for the people living at that time the world looked extremely different. It was for them the cap of fear and terror, a point of no return for sailors.
But there was also a kind of people who were bursting with curiosity and scientific exploration. She, or in this case a he, had decided to approach the subject of exploring the world in a more focused and thoughtful way.
His name was Prince Henrique with the name <Heinrich the Navigator> and he came from Portugal. A governor of the Algarve.
It was the year 1419, he dedicated his life to the exploration of what could be behind it.
He was very practical, he simply collected all the reports that existed about the areas to be explored.
Thus he had collected in the course of the time an extensive basis for a further proceeding to this situation…..and still another novelty came by him to the run…..
He had a new type of ship developed and also built ! It was called „Karavelle“, it was of course navigation-technically far superior to all previous ship types. So this was the basis mentioned before, a technical basis for the further Portuguese explorations of the seas and their courses. Then, in 1423, he started the first exploratory voyage, towards the south to see what the reality, quite unknown until then, was like.
Now often these ships set out to explore what could be found beyond „Bojador“. However, with a less impressive result. The sailors returned without reporting anything about the world beyond or they remained lost.
It was not until 1434 that Gil Eanes succeeded: he sailed around what had been called the end of the world until then, proving that it was not just that – the „end of the world“ .
What then followed quite leisurely, is certainly known to some of you not sailors, from the school lessons :
– Bartolomeu Dias reaches the Cape of Good Hope in 1488, Vasco da Gama circumnavigates it and reaches India in 1498. Shortly before, in 1492, Christopher Columbus arrives in „West Indies“??? on behalf of the Spanish Crown, ……thought he….. the other side of our planet. But then not much later it was Ferdinand Magellan who now sails around the „world“ from Europe around Cape Horn and arrives back in Europe.
– A new age of knowledge and knowledge begins. This became clear to many like „beef broth“. Large parts of mankind breathed a sigh of relief :
– So the earth is a sphere. It has no edge and here there are no mystical borders, behind which possibly unknown powers rule.
Once again it had been shown that people always believe first in a legendary fairy tale from old times just because of ignorance. And this fairy tale was for them just at that time – the earth as a finite disk -.
Now pay attention, I go back briefly. Centuries back into the time of Aristotle. He had already argued in the fourth century B.C. as follows :
– the earth must be a sphere, since with ships sailing away from the coast first the hull and only then the sails disappeared.
– Further, the next statement, the earth shadow with a lunar eclipse was always round.
These realizations remained in the further quite in the world view. In somewhat educated circles there was hardly any talk about a flat earth from which one could still crash. It showed up very clearly as the at that time probably most influential church teacher of the Middle Ages, called , Thomas of Aquin, the situation nearly two hundred years before Henry the Navigator so summarized :
It is basically the star expert, because it is he who proves by solar and lunar eclipses that our planet „Earth“ is round after all. The long lasting waffling was completely strange and repugnant to him.
Even if I repeat myself, how often it was a Greek earth citizen who approached the determination of the earth circumference. His name was „Eratosthenes“. (See above sketch….so about 190 years before Chr.
This man was an astronomer and tried it by solar measurements in Egypt. For by comparing the noon position of the sun in the city of Syene and today’s Aswan, with that in Alexandria. It should be noted, both cities are located on the same longitude, so that no difference in time could lead to errors.
I point briefly to a small explanation, which is to be understood however relatively fast.
Let’s start in Syene, if there the sun was in the zenith, that is shown in point a, then in Alexandria point b it is away from the zenith by an angle a= 1/50 of a full circle.
As you can see, 𝜀 is also the angle between lines from the center of the Earth to Syene and Alexandria. For this reason, fifty times the distance L between the two cities must just equal the circumference of the Earth.
Now one must say, what was done now at that time
would be done differently nowadays.
In those days the distance has been determined by so called
royal pedometers. Pacemakers were simple officials of the court with a very special ability. They could easily march long distances in as equal a stride as possible.
They had walked the distance L with 5000 stadia, which were about 750 kilometers according to the calculations of that time. So the circumference of the earth was 50 × 750 = 37,500 kilometers.
And look at one, our today’s measurements lead on about 40,000 kilometers for the polar circumference and confirm therefore in the best way both the logic of the intelligent Eratosthenes and the real precision of the royal Egyptian pedometers living at that time.
This can only mean that the resulting idea of the earth as a sphere was known, but only as a theory.
Theory and reality are two different things, that was already known at that time and the following men have shown it; Gil Eanes, Vasco da Gama, Columbus, Magellan. So our earthly world was finite and it was a sphere. But this was now no more a theory, but the reality. It was perceptible as a given, appearance, simply experienceable.
…it fowllows Part 6