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The Kingdom of Prester John, Christianity’s Imaginary Ally
Prester John as virtual as he was virtuous, the legend literally too good to be true.
In 1145, the Syrian bishop Hugo of Jabala brought Pope Eugene III the news of the Muslim reconquest of Edessa, an important Crusader stronghold in the Holy Land. The bishop softened the blow – and hoped to encourage the Pope to a new Crusade – with tales of a mighty Christian king attacking the Muslims from behind: Prester John, a descendant of one of the Three Magi and ruler of a Christian Empire beyond the Muslim-ruled lands in India, on the very edge of the world then known to Europe. According to Otto von Freising’s contemporary Chronicles, Hugo spoke of “a certain Prester John who lives in the Far East, beyond Persia and Armenia, King and Priest, Christian but Nestorian (1), having waged war against the Persian and Median dynasty of the Sarmiads, having chased them from their capital Ectabana.” This raised the possibility of a Christian pincer attack on the Muslim world.
Twenty years later, a letter addressed by Prester John to the Byzantine Emperor Manuel I Comnenus caused a great stirring of hope in all of Christendom. Pope Alexander III sent out an envoy to the Prester, but without result (the fate of the papal diplomat is unknown). The letter, however, remained a powerful tonic to a Europe feeling hemmed in by the Muslim ascendancy in the Middle East and Northern Africa. It was copied (and embellished) for many decades afterwards. The letter described a Christian empire with 72 tributary kingdoms, in an area of the world with a fantastic ecology inhabited, among others, by vampires and dog-headed people. The Fountain of Youth and a river flowing from Paradise itself and filled with precious stones helped complete a picture of thrilling exoticism. And of perfect piety, happiness and wealth: “All Christian values are respected to the letter. Theft, greed and lies are unknown. There is no poverty.”
But the letter was a forgery, Prester John as virtual as he was virtuous, the legend literally too good to be true. All Prester John ever was king of, was Wishful Thinking. Prester John’s fictional empire proved as movable as the imagination of beleaguered Christianity required. First inferred in India, the kingdom was later situated in Central Asia, and eventually assumed to be in Africa. The ease of these huge locational shifts was due not just to Europe’s dim perception of geography at the time, but also to the elasticity of the contemporary concept of ‘India’, which in its broadest interpretation could stretch all the way from Africa to China.
Whatever its location du jour, Prester John’s legend required his kingdom to be beyond Muslim lands, and in a little-known corner of the world. The last, longest and strongest association of the legend was with Abyssinia (2) – mainly because, apart from conforming to the legend’s geographical requirements, it also did happen to be a Christian empire. In his Mirabilia (1323), Jourdain de Séverac identified the Abyssinian Negus (i.e. Emperor and supreme leader of the Abyssinian monophysite church) with Prester John, spurring European expeditions to the African empire. In 1490, the Portuguese explorer Pêro da Covilhã managed to convey a letter from the king of Portugal to the Negus… even though the letter itself was addressed to Prester John. This must have surprised the Negus, but that did not stop Europeans from continuing to the conceit – even though the Ethiopians in their intermittent contacts with European Christendom tried to clarify that their Emperor certainly wasn’t anyone’s “Prester”. Only in the 17th century did Europeans realise their mistake, and Prester John finally faded from maps, and from memory. Prester John might never have been real, but his influence can be felt clearly; in the push of European exploration around Africa towards India and Ethiopia, and in cultural references ranging from William Shakespeare and Umberto Eco to Marvel Comics (3).
This map, dating from the 1570s, still takes Europe’s devout wishes for geopolitical truth. It was produced in Antwerp by Ortelius, entitled A Description of The Empire of Prester John, Also Known as the Abyssinian Empire. It delineates Prester John’s empire as follows: its borders almost reach north to Aswan (noted on the map as Aßuan) on the Nile, then follow the Nile, Niger and Manicongo rivers south to the Mountains of the Moon (Lunae montes, hinc Austrum versus Africa veteribus incognita fuit: The Mountains of the Moon, ‘Africa south from here was unknown to the Ancients’). The kingdom extends from these western and southern borders all the way to Africa’s eastern shores.
Ortelius’ map mixes up familiar and imagined names and locations into an intriguing mess of real and imagined geography.
* In northern Africa are Barbaria (the Barbary Coast) and Egypt, on the western African coast are other place names that still sound familiar: Benin, Biafar (Biafra?), Rio de los Camarones (Cameroon), Manicongo (Congo), Angolia (Angola).
* The Mountains of the Moon in Central Africa were known to Greek geographers as early as Ptolemy (although he might have referred to the Kilimanjaro instead). On this map, they are situated far south of the Equator. Mozambique, named by Portuguese explorers in the late 15th century, possibly after a lokal sheikh called Moussa ibn Mbeki, is on the coast and appears north of the Mountains of the Moon.
* The interior is dominated by a few great lakes, probably a garbled reference to the actual Great Lakes. They are named Zaire lacus (or Zembre lacus), near which amazons live and in which sirens swim, and Zaflan lacus. Zaire, the name of the Democratic Republic of the Congo between 1971 and 1997, is a Portuguese corruption of the Congolese word nzere, ‘the river that swallows all rivers’.
* In the interior of Prester John’s kingdom is a legend that appears to read: ‘Mount Amara, here the sons of Prester John are held in captivity by [a] governor’.
* On the Arabian peninsula, two cities are referenced: Mecha, patria Mahumetis (‘Mecca, the home of Muhammad’), and Medina Talnabi, ubi Mahumetis sepulcrum magna frequentia visitur (‘Medina Talnabi, where the tomb of Muhammad is visited with great frequency’). Two other cities, Aden and Zibir (possibly Sana’a) are located in (or to)the south of Aiman, quae olim Arabia Felix (‘Yemen, formerly Happy Arabia’).
This map was taken from this page at Princeton University Library. The page quotes Jonathan Swift, as “[t]his is certainly one of the maps that [he] had in mind when he wrote: So Geographers in Afric-maps With Savage-Pictures fill their Gaps; And o’er uninhabitable Downs Place Elephants for want of Towns – On Poetry: A Rhapsody (1733)
Strange Maps #434
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(1) a Christian heresy regarding Jesus as two persons, human and divine, that at one time spread deep into Central Asia.
(2) synonymous with the Ethiopian Empire, which existed from 1137 until well into the 20th century. After the coup d’etat in 1978 which deposed the country’s last emperor, it has generally only been referred to as Ethiopia.
(3) in Much Ado About Nothing, Baudolino and the Fantastic Four, respectively.
Why mega-eruptions like the ones that covered North America in ash are the least of your worries.
- The supervolcano under Yellowstone produced three massive eruptions over the past few million years.
- Each eruption covered much of what is now the western United States in an ash layer several feet deep.
- The last eruption was 640,000 years ago, but that doesn't mean the next eruption is overdue.
The end of the world as we know it
Panoramic view of Yellowstone National Park
Image: Heinrich Berann for the National Park Service – public domain
Of the many freak ways to shuffle off this mortal coil – lightning strikes, shark bites, falling pianos – here's one you can safely scratch off your worry list: an outbreak of the Yellowstone supervolcano.
As the map below shows, previous eruptions at Yellowstone were so massive that the ash fall covered most of what is now the western United States. A similar event today would not only claim countless lives directly, but also create enough subsidiary disruption to kill off global civilisation as we know it. A relatively recent eruption of the Toba supervolcano in Indonesia may have come close to killing off the human species (see further below).
However, just because a scenario is grim does not mean that it is likely (insert topical political joke here). In this case, the doom mongers claiming an eruption is 'overdue' are wrong. Yellowstone is not a library book or an oil change. Just because the previous mega-eruption happened long ago doesn't mean the next one is imminent.
Ash beds of North America
Ash beds deposited by major volcanic eruptions in North America.
Image: USGS – public domain
This map shows the location of the Yellowstone plateau and the ash beds deposited by its three most recent major outbreaks, plus two other eruptions – one similarly massive, the other the most recent one in North America.
The Huckleberry Ridge eruption occurred 2.1 million years ago. It ejected 2,450 km3 (588 cubic miles) of material, making it the largest known eruption in Yellowstone's history and in fact the largest eruption in North America in the past few million years.
This is the oldest of the three most recent caldera-forming eruptions of the Yellowstone hotspot. It created the Island Park Caldera, which lies partially in Yellowstone National Park, Wyoming and westward into Idaho. Ash from this eruption covered an area from southern California to North Dakota, and southern Idaho to northern Texas.
About 1.3 million years ago, the Mesa Falls eruption ejected 280 km3 (67 cubic miles) of material and created the Henry's Fork Caldera, located in Idaho, west of Yellowstone.
It was the smallest of the three major Yellowstone eruptions, both in terms of material ejected and area covered: 'only' most of present-day Wyoming, Colorado, Kansas and Nebraska, and about half of South Dakota.
The Lava Creek eruption was the most recent major eruption of Yellowstone: about 640,000 years ago. It was the second-largest eruption in North America in the past few million years, creating the Yellowstone Caldera.
It ejected only about 1,000 km3 (240 cubic miles) of material, i.e. less than half of the Huckleberry Ridge eruption. However, its debris is spread out over a significantly wider area: basically, Huckleberry Ridge plus larger slices of both Canada and Mexico, plus most of Texas, Louisiana, Arkansas, and Missouri.
This eruption occurred about 760,000 years ago. It was centered on southern California, where it created the Long Valley Caldera, and spewed out 580 km3 (139 cubic miles) of material. This makes it North America's third-largest eruption of the past few million years.
The material ejected by this eruption is known as the Bishop ash bed, and covers the central and western parts of the Lava Creek ash bed.
Mount St Helens
The eruption of Mount St Helens in 1980 was the deadliest and most destructive volcanic event in U.S. history: it created a mile-wide crater, killed 57 people and created economic damage in the neighborhood of $1 billion.
Yet by Yellowstone standards, it was tiny: Mount St Helens only ejected 0.25 km3 (0.06 cubic miles) of material, most of the ash settling in a relatively narrow band across Washington State and Idaho. By comparison, the Lava Creek eruption left a large swathe of North America in up to two metres of debris.
The difference between quakes and faults
The volume of dense rock equivalent (DRE) ejected by the Huckleberry Ridge event dwarfs all other North American eruptions. It is itself overshadowed by the DRE ejected at the most recent eruption at Toba (present-day Indonesia). This was one of the largest known eruptions ever and a relatively recent one: only 75,000 years ago. It is thought to have caused a global volcanic winter which lasted up to a decade and may be responsible for the bottleneck in human evolution: around that time, the total human population suddenly and drastically plummeted to between 1,000 and 10,000 breeding pairs.
Image: USGS – public domain
So, what are the chances of something that massive happening anytime soon? The aforementioned mongers of doom often claim that major eruptions occur at intervals of 600,000 years and point out that the last one was 640,000 years ago. Except that (a) the first interval was about 200,000 years longer, (b) two intervals is not a lot to base a prediction on, and (c) those intervals don't really mean anything anyway. Not in the case of volcanic eruptions, at least.
Earthquakes can be 'overdue' because the stress on fault lines is built up consistently over long periods, which means quakes can be predicted with a relative degree of accuracy. But this is not how volcanoes behave. They do not accumulate magma at constant rates. And the subterranean pressure that causes the magma to erupt does not follow a schedule.
What's more, previous super-eruptions do not necessarily imply future ones. Scientists are not convinced that there ever will be another big eruption at Yellowstone. Smaller eruptions, however, are much likelier. Since the Lava Creek eruption, there have been about 30 smaller outbreaks at Yellowstone, the last lava flow being about 70,000 years ago.
As for the immediate future (give or take a century): the magma chamber beneath Yellowstone is only 5 percent to 15 percent molten. Most scientists agree that is as un-alarming as it sounds. And that its statistically more relevant to worry about death by lightning, shark, or piano.
Strange Maps #1041
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The potential of CRISPR technology is incredible, but the threats are too serious to ignore.
- CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) is a revolutionary technology that gives scientists the ability to alter DNA. On the one hand, this tool could mean the elimination of certain diseases. On the other, there are concerns (both ethical and practical) about its misuse and the yet-unknown consequences of such experimentation.
- "The technique could be misused in horrible ways," says counter-terrorism expert Richard A. Clarke. Clarke lists biological weapons as one of the potential threats, "Threats for which we don't have any known antidote." CRISPR co-inventor, biochemist Jennifer Doudna, echos the concern, recounting a nightmare involving the technology, eugenics, and a meeting with Adolf Hitler.
- Should this kind of tool even exist? Do the positives outweigh the potential dangers? How could something like this ever be regulated, and should it be? These questions and more are considered by Doudna, Clarke, evolutionary biologist Richard Dawkins, psychologist Steven Pinker, and physician Siddhartha Mukherjee.
Measuring a person's movements and poses, smart clothes could be used for athletic training, rehabilitation, or health-monitoring.
In recent years there have been exciting breakthroughs in wearable technologies, like smartwatches that can monitor your breathing and blood oxygen levels.
But what about a wearable that can detect how you move as you do a physical activity or play a sport, and could potentially even offer feedback on how to improve your technique?
And, as a major bonus, what if the wearable were something you'd actually already be wearing, like a shirt of a pair of socks?
That's the idea behind a new set of MIT-designed clothing that use special fibers to sense a person's movement via touch. Among other things, the researchers showed that their clothes can actually determine things like if someone is sitting, walking, or doing particular poses.
The group from MIT's Computer Science and Artificial Intelligence Lab (CSAIL) says that their clothes could be used for athletic training and rehabilitation. With patients' permission, they could even help passively monitor the health of residents in assisted-care facilities and determine if, for example, someone has fallen or is unconscious.
The researchers have developed a range of prototypes, from socks and gloves to a full vest. The team's "tactile electronics" use a mix of more typical textile fibers alongside a small amount of custom-made functional fibers that sense pressure from the person wearing the garment.
According to CSAIL graduate student Yiyue Luo, a key advantage of the team's design is that, unlike many existing wearable electronics, theirs can be incorporated into traditional large-scale clothing production. The machine-knitted tactile textiles are soft, stretchable, breathable, and can take a wide range of forms.
"Traditionally it's been hard to develop a mass-production wearable that provides high-accuracy data across a large number of sensors," says Luo, lead author on a new paper about the project that is appearing in this month's edition of Nature Electronics. "When you manufacture lots of sensor arrays, some of them will not work and some of them will work worse than others, so we developed a self-correcting mechanism that uses a self-supervised machine learning algorithm to recognize and adjust when certain sensors in the design are off-base."
The team's clothes have a range of capabilities. Their socks predict motion by looking at how different sequences of tactile footprints correlate to different poses as the user transitions from one pose to another. The full-sized vest can also detect the wearers' pose, activity, and the texture of the contacted surfaces.
The authors imagine a coach using the sensor to analyze people's postures and give suggestions on improvement. It could also be used by an experienced athlete to record their posture so that beginners can learn from them. In the long term, they even imagine that robots could be trained to learn how to do different activities using data from the wearables.
"Imagine robots that are no longer tactilely blind, and that have 'skins' that can provide tactile sensing just like we have as humans," says corresponding author Wan Shou, a postdoc at CSAIL. "Clothing with high-resolution tactile sensing opens up a lot of exciting new application areas for researchers to explore in the years to come."
The paper was co-written by MIT professors Antonio Torralba, Wojciech Matusik, and Tomás Palacios, alongside PhD students Yunzhu Li, Pratyusha Sharma, and Beichen Li; postdoc Kui Wu; and research engineer Michael Foshey.
The work was partially funded by Toyota Research Institute.