Piri Re'is map
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[edit] Definition
[edit] Provenance
The Piri Re'is map was discovered in the Imperial palace in Constantinople in 1929. According to the notes made on it, the map was constructed by the Turkish admiral Piri Ibn Haji Memmed, also known as Piri Re'is, in the spring of 1513 AD, using several other maps as source material. There is no doubt as to its authenticity.
[edit] Discussion
It has been claimed that the Piri Re'is map shows geographical knowledge unknown to the people of Piri Re'is's day [1]. Now the fundamental axiom of pseudohistory is that anything which seems too advanced for its time must in fact have very ancient origins: and on that basis it is claimed that the maps Piri Re'is used as sources must have originated with some ancient yet technically advanced civilisation, now lost. This idea was first advanced by Charles H. Hapgood in his book Maps of the Ancient Sea Kings; a later book, When The Sky Fell would (predictably) identify this civilization with Atlantis. It has also become part of the stock in trade of Young Earth Creationists as something "evolutionists can't explain" [2], and they attribute this supposedly advanced knowledge to a culture existing before the Flood.
Claim : Piri Re'is writes that the map was made using "charts drawn in the days of Alexander, Lord of the Two Horns [i.e. Alexander the Great]", yet it shows the Americas and Antarctica, which were unknown in those days.
Response : This is a prime example of quotation out of context. To quote Piri Re'is more fully:
- "From about twenty charts and Mappae Mundi--these are charts drawn in the days of Alexander, Lord of the Two Horns, which show the inhabited quarter of the world; the Arabs name these charts Jaferiye--from eight Jaferiyes of that kind and one Arabic map of Hind, and from the maps just drawn by four Portuguese which show the countries of Hind, Sind and China geometrically drawn, and also from a map drawn by Colombo [i.e. Christopher Columbus] in the western region I have extracted it." [3]
We should also note that Piri Re'is's notes definitely attribute the discovery of the Americas to Columbus ("a Genoese infidel, his name was Colombo [i.e. Columbus]") in the year 896 AH (i.e 1491-2 AD). Piri Re'is would hardly have written that if he had known of any older maps showing the Americas.
Claim : The map shows Antarctica, which wasn't discovered until 1819.
Response : To be precise, the map shows the coastline of South America curving round to the East until it is due south of West Africa. The notes on the map say that this country is hot and full of snakes, and notes that "for this reason the Portuguese infidels did not land on these shores", implying that they knew where it was --- unlike Antarctica.
Claim : The map shows knowledge of map projections, unknown at the time of Piri Re'is.
Response : The first part of this claim may quite possibly be true. The second is not. Map projections had been discussed by the ancient Greeks, and most significantly they were explained by Ptolemy (in the second century AD) in the first chapter of his hugely influential Guide to Geography. This was first translated into Arabic in the ninth century AD [4] : it would have been known to Piri Re'is and every other Muslim cartographer of his period. Indeed, it is specifically claimed by enthusiasts for the Piri Re'is map that:
- "The "center" of the source map projected from coordinates in what is now Alexandria - the center of culture and home of the world's oldest and largest library until its destruction by Christian invaders."
I will give you one guess as to where Ptolemy lived.
There is some debate among scholars as to whether, and to what extent, knowledge of map projections was used in the construction of the so-called "portolan maps" of the Middle Ages [5], including the maps of Piri Re'is, as just one case in point out of many. We may note in this connection that amongst the sources Piri Re'is mentions are "the maps just drawn by four Portuguese which show the countries of Hind, Sind and China geometrically drawn." [6]
Claim : The map shows knowledge of the circumference of the Earth to within 50 miles.
Response : We cannot determine on what this claim could be based. The notes to the map do not give the circumference of the Earth: indeed the only distances given are those of the voyage from the Pillars of Hercules to the Antilles (given as 4000 miles) and from "the point of Abyssinia [Ethiopia]" to "Shuluk" ("Sri Lanka", perhaps?) in India (4200 miles). These nice round figures hardly show exact knowledge of anything.
However, there is no difficulty in supposing that Piri Re'is did know the circumference of the Earth to a high degree of accuracy. The method for measuring the circumference of the Earth [7] had been known since the days of Eratosthenes in the third century BC [8]; the Muslim world was keen on such questions, and on spherical geometry in general [9], partly from religious motivations: for example, it was necessary to calculate the exact direction of Mecca (the "qibla") to know exactly which way to face when praying. As a cartographer, Piri Re'is would have taken care to have the best measurements.
Claim : The map shows the ability to measure latitudes in the southern hemisphere, but in the sixteenth century no-one knew how to do this, as their only method of measuring latitude was to take a sighting on the North Star.
Response : In Piri Re'is's day there were at least two ways of measuring latitude: by sighting on the North Star; and by sighting on the sun at noon. Shipboard navigators had been using an instrument called an astrolabe for just such a purpose since about 1400 AD [10], and this method works just as well in the southern as in the northern hemisphere.
