Image credit: WMG, University of Warwick
Posted on 10/26/2017 1:39:00 PM PDT by Oatka
Image credit: WMG, University of Warwick
Researchers at the University of Warwick have identified what is believed to be the earliest known marine navigation tool ever discovered.
The artifact, now determined to be an astrolabe, was excavated in 2014 from the wreck of a Portuguese explorer ship which sank during a storm in the Indian Ocean in 1503. The ship was called the Esmeralda, part of a fleet led by Portuguese explorer Vasco da Gama, the first person to sail directly from Europe to India.
The astrolabe is believed to date from between 1495 and 1500, which would make it the earliest known marine navigation tool ever discovered, according to the researchers. The tool would have been used by mariners to measure the altitude of the sun, helping them determine their location on the high seas.
Although the 17.5cm diameter bronze disc was believed to be an astrolabe, it had no visible navigational markings – only engravings that have since been identified as Portuguese coat of arms and the personal emblem of Don Manuel I, the King of Portugal from 1495-1521.
Professor Mark Williams from WMG, University of Warwick, was tasked with scanning the artifact using pioneering scanning analysis technology and 3D imaging, revealing tiny details invisible to the human eye. The scans showed etches around the edge of the object, each separated by five degrees – proving that it is, in fact, an astrolabe.
“It was fantastic to apply our 3D scanning technology to such an exciting project and help with the identification of such a rare and fascinating item,” said Williams. “Usually we are working on engineering-related challenges, so to be able to take our expertise and transfer that to something totally different and so historically significant was a really interesting opportunity.”
David Mearns, from Blue Water Recovery, who led the excavation, commented:
“It’s a great privilege to find something so rare, something so historically important, something that will be studied by the archaeological community and fills in a gap.
“It was like nothing else we had seen […] it adds to the history, and hopefully astrolabes from this period can be found.”
Ping......welcome back you were missed
I know someone who could have used it since they apparently forgot all the fancy modern stuff.
http://freerepublic.com/focus/news/3598929/posts?page=1
The Portuguese don’t get enough credit.
They were an extremely tough bunch. Won a huge empire with a few hundred or a few dozen men, sometimes, against incredible odds.
And they were far ahead of the rest of Europe with tools and techniques just like this astrolabe, plus navigation guides (instrument positions of landmarks, of tides and currents and winds). A lot of the later Europeans copied their things directly, and often hired them (Magellan for instance) when heavy duty navigating had to be done.
I thought the aliens that visited us 4000 years ago left some navigation equipment in the desert. How can this be older?
and it is still usable to navigate with.
I thought the aliens that visited us 4000 years ago left some navigation equipment in the desert. How can this be older?
= = =
The aliens, anticipating this event, falsified their copyright/patent date.
It has already been debunked.
Don’t expect them to get any credit in the larger media; they’ll find a round plain rock in Africa and insist Africans invented the astrolabe (and the Portuguese stole it). Can’t focus on European accomplishments, you know?
An astrolabe was a horrible device to use. The navigator hung it from his left thumb to get it vertical. Then he looked directly at the sun over the sighting arm and moved the arm up or down to point directly at the sun and get a reading. What with the rolling and pitching of the ship, there was little hope of an accurate sighting. Add to that the direct sun viewing burned out many navigators’ corneas and it was a horrible job.
On a serious note reason Portugal might be slighted in the history from this period is that for more than half a century they’d been merged back into Spain (regaining independence in the second half of the 1600s).
Portugal was Europe’s most advanced society, not ton mention it also had the largest collection of sea maps then existing. Alas, all those maps which were SAP like document of the time were lost in the great Lisbon quake in the 18th century.
However, when Portuguese navigators arrived in Africa, they asked the Crown if they could remain since the living conditions were so superior - hot and cold fresh running water, sewers and more ... All that was then disappeared as the guns for slave trade ramped up, leaving the old African wooden cities to become just more jungle.
“The navigator hung it from his left thumb to get it vertical. Then he looked directly at the sun over the sighting arm and moved the arm up or down to point directly at the sun and get a reading. “
I don’t buy it. Any navigator with half a brain would flip it over and use the shadow of his thumb to do the same thing. No need to look at the sun. Sounds like the sort of speculated usage some historians came up with by totally guesswork. Experimental archeology is disproving a lot of that sort of junk these days. Reconstruct a device and give it to some non-morons to figure out and they usually can come up with something that makes more sense than the ‘conventional wisdom’.
Meh, big deal. The Antikythera mechanism is at least 1500 years older and far more advanced.
That is what I was thinking, with the pitching and rolling of a ship in the ocean how do you really get an accurate reading? I mean dead calm, okay. But with the bobbing up and down, I would think difficult.
“Meh, big deal. The Antikythera mechanism is at least 1500 years older and far more advanced.”
But as far as anyone can tell, no such device was actually used, for any practical purpose, in antiquity. It was a toy, not a tool. Nor did the ancients have the other technologies to make a go of it beyond the pillars of Hercules, the ne plus ultra - nothing beyond this.
But astrolabes, and the techniques of using them, were standard issue by the late 15th century, and indeed these were further developed and their use taught at Henry the Navigators (1398-1460) R&D facility and college of navigation, at Sagres. This was a very impressive achievement for those days, a focused R&D program and a tech grad school.
And the Portuguese did use them, taking readings wherever they could, leading the way to a much more accurate picture of the world.
Land. Take a reading. A lot of what they did was along coasts.
Also, on a ship, take several readings, average them out, and you have a better idea than none at all. An instrument does not have to be perfect to be useful.
It can thus be used to identify stars or planets, to determine local latitude given local time (and vice versa), to survey, or to triangulate. It was used in classical antiquity, the Islamic Golden Age,[1] the European Middle Ages, and the Renaissance for all these purposes.
The astrolabe is effective for determining latitude on land or calm seas, although it is less reliable on the heaving deck of a ship in rough seas. The mariner’s astrolabe was developed to solve that problem. ...”
An early astrolabe was invented in the Hellenistic civilization by Apollonius of Perga between 220 and 150 BC, often attributed to Hipparchus.
The astrolabe was a marriage of the planisphere and dioptra, effectively an analog calculator capable of working out several different kinds of problems in spherical astronomy. Theon of Alexandria (c. 335 – c. 405) wrote a detailed treatise on the astrolabe, and Lewis[8] argues that Ptolemy used an astrolabe to make the astronomical observations recorded in the Tetrabiblos.
Some historians attribute the astrolabe’s invention to Hypatia, the daughter of Theon of Alexandria,[9] noting that her student Synesius credits her for the invention in his letters.[10]
Astrolabes continued in use in the Greek-speaking world throughout the Byzantine period. About 550 AD, Christian philosopher John Philoponus wrote a treatise on the astrolabe in Greek, which is the earliest extant treatise on the instrument.[a]
Mesopotamian bishop Severus Sebokht also wrote a treatise on the astrolabe in the Syriac language in the mid-7th century.[b]
Sebokht refers to the astrolabe as being made of brass in the introduction of his treatise, indicating that metal astrolabes were known in the Christian East well before they were developed in the Islamic world or in the Latin West.[11]
Medieval era:
A treatise explaining the importance of the astrolabe by Nasir al-Din al-Tusi, Persian scientist
Astrolabe of Jean Fusoris (fr), made in Paris, 1400
Animation showing how celestial and geographic coordinates are mapped on an astrolabe’s tympan through a stereographic projection. Hypothetical tympan (40 degrees North Latitude) of a 16th-century European planispheric astrolabe.
Astrolabes were further developed in the medieval Islamic world, where Muslim astronomers introduced angular scales to the design,[12] adding circles indicating azimuths on the horizon.[13]
It was widely used throughout the Muslim world, chiefly as an aid to navigation and as a way of finding the Qibla, the direction of Mecca. Eighth-century mathematician Muhammad al-Fazari is the first person credited with building the astrolabe in the Islamic world.[14]
The mathematical background was established by Muslim astronomer Albatenius in his treatise Kitab az-Zij (c. 920 AD), which was translated into Latin by Plato Tiburtinus (De Motu Stellarum). The earliest surviving astrolabe is dated AH 315 (927–28 AD).[15]
In the Islamic world, astrolabes were used to find the times of sunrise and the rising of fixed stars, to help schedule morning prayers (salat).
In the 10th century, al-Sufi first described over 1,000 different uses of an astrolabe, in areas as diverse as astronomy, astrology, navigation, surveying, timekeeping, prayer, Salat, Qibla, etc.[16][17]
Astrolabium Masha’Allah Public Library Bruges (nl) Ms. 522
The spherical astrolabe was a variation of both the astrolabe and the armillary sphere, invented during the Middle Ages by astronomers and inventors in the Islamic world.[c]
The earliest description of the spherical astrolabe dates back to Al-Nayrizi (fl. 892–902).
In the 12th century, Sharaf al-Din al-Tusi invented the linear astrolabe, sometimes called the “staff of al-Tusi”, which was “a simple wooden rod with graduated markings but without sights.
It was furnished with a plumb line and a double chord for making angular measurements and bore a perforated pointer”.[18] The geared mechanical astrolabe was invented by Abi Bakr of Isfahan in 1235.[19]
Peter of Maricourt wrote a treatise on the construction and use of a universal astrolabe in the last half of the 13th century entitled Nova compositio astrolabii particularis. Universal astrolabes can be found at the History of Science Museum in Oxford.
English author Geoffrey Chaucer (c. 1343–1400) compiled A Treatise on the Astrolabe for his son, mainly based on Messahalla.
The same source was translated by French astronomer and astrologer Pélerin de Prusse and others. The first printed book on the astrolabe was Composition and Use of Astrolabe by Christian of Prachatice, also using Messahalla, but relatively original.
In 1370, the first Indian treatise on the astrolabe was written by the Jain astronomer Mahendra Suri.[20]
The first known metal astrolabe in Western Europe is the Destombes astrolabe made from brass in tenth-century Spain.[21][22]
Metal astrolabes avoided the warping that large wooden ones were prone to, allowing the construction of larger and therefore more accurate instruments. Metal astrolabes were heavier than wooden instruments of the same size, making it difficult to use them in navigation.[23]
The astrolabe was almost certainly first brought north of the Pyrenees by Gerbert of Aurillac (future Pope Sylvester II), where it was integrated into the quadrivium at the school in Reims, France sometime before the turn of the 11th century.[24]
In the 15th century, French instrument maker Jean Fusoris (c. 1365–1436) also started remaking and selling astrolabes in his shop in Paris, along with portable sundials and other popular scientific devices of the day. Thirteen of his astrolabes survive to this day.[25]
One more special example of craftsmanship in early 15th-century Europe is the astrolabe designed by Antonius de Pacento and made by Dominicus de Lanzano, dated 1420.[26]
In the 16th century, Johannes Stoffler published Elucidatio fabricae ususque astrolabii, a manual of the construction and use of the astrolabe. Four identical 16th-century astrolabes made by Georg Hartmann provide some of the earliest evidence for batch production by division of labor.
Astrolabes and clocks
Mechanical astronomical clocks were initially influenced by the astrolabe; they could be seen in many ways as clockwork astrolabes designed to produce a continual display of the current position of the sun, stars, and planets. For example, Richard of Wallingford’s clock (c. 1330) consisted essentially of a star map rotating behind a fixed rete, similar to that of an astrolabe.[27]
Many astronomical clocks use an astrolabe-style display, such as the famous clock at Prague, adopting a stereographic projection (see below) of the ecliptic plane. In recent times, astrolabe watches have become popular.
For example, Swiss watchmaker Dr. Ludwig Oechslin designed and built an astrolabe wristwatch in conjunction with Ulysse Nardin in 1985. Dutch watchmaker Christaan van der Klauuw also manufactures astrolabe watches today. ...”
The earliest navigation tool is a compass. More fake headlines in search of hits.
It had to do with the loss of the flower of Portuguese chivalry at a critical juncture, which in turn led to a consolidation of Spanish control over Iberia and the former colonies of Portugal.
Battle of Ksar El Kebir: The Battle of Three Kings, Morocco 1578
http://warfarehistorian.blogspot.com/2013/08/battle-of-ksar-el-kebir-morocco-1578.html
Thanks stockpirate for the ping and kind remarks! Thanks Oatka for the topic.
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