Portolan Charts 'Too Accurate' to be Medieval
Who in history was clever enough to have made these maps?
Portolan charts, it was always assumed, were compiled by medieval European mapmakers from contemporary sources. A Dutch doctoral dissertation now disproves this: these nautical charts are impossibly accurate, not just for medieval Europe, also for other likely sources, the Byzantines and the Arabs. So who made them – and when?
Mystery has always shrouded the sudden emergence, seemingly ex nihilo, of portolan charts. The oldest known example emerged in Pisa around 1290, without any obvious antecedents. This Carta Pisana kick-started a tradition of amazingly accurate sea charts almost up to modern standards, although as with most other portolans, that accuracy was mainly limited to the Mediterranean and the Black Sea.
A typical portolan chart showed coastal contours and the location of harbours and ports, ignoring virtually all inland features. It would be criss-crossed by straight lines, connecting opposite shores by any of the 32 directions of the mariner's compass, thus facilitating navigation.
After popping up in Italy, portolans became coveted possessions in the seafaring nations of Spain and Portugal, where they ranked as state secrets.
Little or nothing is known of their origins and production, so the working hypothesis among cartographic historians was that portolans were somehow gathered together from the knowledge of medieval European sailors, possibly enhanced with older knowledge from Byzantine or Arab sources.
That hypothesis has now been disproven by Roelof Nicolai, a Dutch geodetic scientist who on 3 March 2016 obtained his doctorate degree from Utrecht University for a dissertation titled A Critical Review of the Hypothesis of a Medieval Origin for Portolan Charts.
In it, Nicolai puts forth the theory that portolan charts were made using techniques that were not at all available to medieval Europeans. So they must have copied them from unknown older sources – in all likelihood while failing to grasp how accurate those maps really were.
Nicolai demonstrates that portolans achieved their accuracy by using what seems like an early version of the Mercator Projection – almost three centuries early. Only in 1569 would the Flemish cartographer introduce his mathematical method of projecting spherical data onto a flat surface that would prove crucial to navigation (straight lines on the map equal straight lines at sea).
In blue: portolan shorelines; in red: actual shorelines. A close match in the Mediterranean and Black Seas, wildly off the mark in the British Isles and the Baltic.
“The portolan maps I've researched all seem to be made using the Mercator Projection”, Nicolai says. “They've all clearly been produced on medieval parchment, but those mapmakers probably didn't realise the accuracy of the maps they were producing. We immediately recognise the shape of the Mediterranean, but even in the Late Middle Ages, that shape was far from established on maps. Nobody really knew how all of the Mediterranean's shorelines ran”.
Nicolai also showed that the portolans weren't produced as single pieces, but in fact are a mosaic: “There are obvious differences of scale and orientation between different areas on portolan maps. Not only does that demonstrate clearly that they were collated from different maps, it also shows that those medieval cartographers were not familiar with the techniques used to produce those different sources”.
The doctorandus also tried to replicate the presumed method by which portolan charts were produced, by averaging the data from numerous single sailing records detailing the location of harbours, the directions of sail, etc. The resulting accuracy was worse by a factor of 10 to that of the actual portolan charts – even while using methods of calculation averages that were developed only at the end of the 17th century. Only in the 19th century did cartographers manage to re-achieve the accuracy of the portolans.
So who was the producer of this anachronistic accuracy? Nicolai only points to the likely source of the maps: Constantinople. “But it is highly unlikely that they were produced there as well. As far as we can tell, the Byzantines really didn't add much to the scientific knowledge inherited from the Classical Age. They only acted as a repository for ancient Greek and Arabic knowledge. And why would the Byzantines even try to chart English and French coastlines? Those were way beyond their sphere of interest”.
Could portolans have an Arabic background? After all, the Arabs were keen astronomers and navigators, giving us the nautical rank of admiral (from 'Amir al Bahr', ruler of the sea). But Nicolai contends the accuracy of the portolans transcends the Arabs' navigational ability of the time. And what we know of Roman and Greek scientific knowledge, for that matter.
“Perhaps we should re-evaluate what we think was the state of science in Antiquity”, says Nicolai. “As long as this doesn't generate any speculation on so-called lost civilisations. As far as these portolans are concerned, we'll just have to think our way back step by step”.
All the way to the alien spaceship that left behind the first portolan maps, of course.
Strange Maps #648
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Whether or not women think beards are sexy has to do with "moral disgust"
- A new study found that women perceive men with facial hair to be more attractive as well as physically and socially dominant.
- Women tend to associate more masculine faces with physical strength, social assertiveness, and formidability.
- Women who display higher levels of "moral disgust," or feelings of repugnance toward taboo behaviors, are more likely to prefer hairy faces.
Beards and perceptions of masculinity<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjU5OTg0MC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NzkxMjM3N30.cH-GqNwP5GVqvstgJWAhBPn1B_lYpVEAI0I7iax7EQw/img.jpg?width=1245&coordinates=0%2C1900%2C0%2C849&height=700" id="caae6" class="rm-shortcode" data-rm-shortcode-id="cb0a355a4e8e1899789bc45f3f7aef56" data-rm-shortcode-name="rebelmouse-image" />
Photo Credit: Wikimedia<p>The study used 919 American (mostly white) women ages 18-70 who rated 30 pictures of men they were shown with various stages of facial hair growth. The photographs depicted men with faces that had been digitally altered to look more feminine or more masculine, with a beard and without a beard. The women rated the men according to perceived attractiveness for long-term and short-term relationships. The study found that the more facial hair the men had, the higher the men were rated on their attractiveness, particularly for their suitability for a long-term relationship.</p><p>Part of this might be attributed to facial masculinity — i.e. protruding brow ridge, wide cheekbones, thick jawline, and deeply set narrow eyes — which conveys information to a woman about a man's underlying health and formidability. Women tend to associate more masculine faces with physical strength and social assertiveness. It can also indicate a man with a superior immune response. The researchers suggested that their findings favoring bearded men could be due to the fact that facial hair enhances the masculine facial features on a man's face, like creating the illusion of a thicker jaw line. This could communicate direct benefits to women like resources and protection that would enhance survival among mothers and their infants. In other words, while a beard doesn't mean superior genetics in and of itself, it might be a primitive, ornamental way of saying, "Hey girl, I'm a testosterone-fueled lean, mean, pathogen fighting machine." <br></p><p>It could also be that a beard becomes its own destiny. The researchers in this study cite prior research that found that by growing a beard, men felt more masculine and had higher levels of serum testosterone, which was linked to a higher level of social dominance. They also tended to subscribe to more old-school beliefs about gender roles in their relationships with women as compared to men with clean-shaven faces.<span></span><br></p>
What does disgust have to do with beard preference?<p>Obviously, not all women dig beards. The researchers were particularly interested in what traits make a women prefer bearded men over clean-shaven faces. They looked into several factors including a woman's disgust levels on various concepts, her desire to become pregnant, and her exposure to facial hair in her personal life. </p><p>According to the study, women who were not into facial hair were turned-off by potential parasites or other critters they imagined could be in the hair or skin. Women ranking high on this "ectoparasite disgust" scale might have viewed beards as a sign of poor grooming habits. However, women who ranked higher in levels of "pathogen" did find the bearded men to be desirable, possibly because they perceived beards as a signal of good health and immune function. An intriguing discovery in the study was links to morality. Women who displayed higher levels of "moral disgust," or feelings of repugnance toward taboo behaviors, were more likely to prefer hairy faces. The authors opined that this could reflect a link between beardedness, politically conservative outlooks, and traditional views regarding performances of masculinity in heterosexual relationships.</p>
Additional findings<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjU5OTg1My9vcmlnaW4uZ2lmIiwiZXhwaXJlc19hdCI6MTYyNDI1NjUyOX0.P9B8WbmJR0q4nfzYZKbuNSA-2SAigVWJgrQE-_Gxlds/img.gif?width=980" id="49143" class="rm-shortcode" data-rm-shortcode-id="2ed3b1d6f20fc170bf2974646e565e8d" data-rm-shortcode-name="rebelmouse-image" />Giphy<p>The correlations that existed between married and single women's rating on the attractiveness of beards were not particularly clear, although the researchers noted that single and married women who wanted children tended to find beards more attractive than the women who didn't want children. They also found that women with bearded husbands found beards to be more attractive, which might indicate that social exposure to beards influences how desirable they are perceived of as being. Or it could be that men with wives who like beards grow beards.</p><p>It's important to note that culture plays a huge role in how attractive women perceive certain male characteristics as being. This study looked at a small, culturally specific group of American women, so no big, universal claims should be made about masculinity, facial hair, and male desirability to women. However, research like this is important in highlighting how human grooming decisions are driven by much more than fashion trends. Sociobiological, economic, and ecological factors all play a part in the way we choose to present ourselves.</p>
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