Black Death Predated 'Small World' Effect, Say Network Theorists 168
KentuckyFC writes "Epidemiologists know that modern diseases can spread almost simultaneously in different parts of the planet because an individual who becomes infected in Hong Kong, for example, can infect friends in New York the following day. This is known as the small world effect. It is the same property that allows any individual to link to another individual anywhere in the world in just a few steps. But in the 14th century, the Black Death spread in a very different way, moving slowly across Europe at a rate of about 2 kilometers a day. Now network theorists have simulated this spread and say it is only possible if the number of long distances travelers in those days was vanishingly small. In other words, people in medieval society were linked almost exclusively to others nearby and so did not form a small world network. That raises an interesting question. If society in 14th century Europe was not a small world but today's society is, when did the change occur? The researchers say the finger of blame points to the invention of railways and steamships which allowed large numbers of people, and the diseases they carried, to travel long distances for the first time."
This makes a lot of sense.. (Score:4, Informative)
The Bubonic plague was carried by the rats. It can only be transmitted human to human in it's final stages and the fleas can't survive long on human body. Two km a day seems about right for rats.
Also, the property of rain is to wet. (Score:2, Informative)
Re:Long distance travel (Score:5, Informative)
Horses are expensive to maintain, and have a rough daily limit of about 30 miles. In comparison, a human walking at 3 mph can go the same distance in only 10 hours. The difference, of course, is that horses can carry more and get there faster, before taking more time to rest.
For the peasants who made up the majority of the population during the 14th century, a horse was a good tool for farmers or messengers, but regular travel would best be done on foot with a light pack and a steady pace.
Re:interesting question (Score:4, Informative)
Re:Long distance travel (Score:5, Informative)
There are other ways that the plague could spread. Yes, someone infected with the plague would die before reaching their destination. However, ships also carried cargo, which could be contaminated. Standard procedure was to quarantine ships and their cargo but, understandably, there could be pressures to rush things because people didn't like their precious fabrics to be kept on an isolated island for forty days, especially since they could easily get damaged in the process.
This is how the Great Plague of Marseilles began: a ship laden with cargo belonging to important people was not quarantined according to procedure. Unfortunately, it had come from the Middle East where the plague was rampant and it starting spreading through the city.
Re:Long distance travel (Score:3, Informative)
Very good point.
And sum to it that people had a very good reason to do that as many laborers mved from place to place for the harvests.
Here in Central Europe young men used to travel long distances during their time of apprenticeship in the different guilds, this tradition is still held in Germany (Wanderschaft). Guilds like the stonemasons travelled from Spain to Cenral Europe and you can find their guild emblems in Romanic and Gothic buildings across the whole continent. Some may even have been in Africa with the Arabs during the period of Al Andalus.
Re:Long distance travel (Score:5, Informative)
Horses are expensive to maintain, and have a rough daily limit of about 30 miles. In comparison, a human walking at 3 mph can go the same distance in only 10 hours.
That's not comparable. The horse could do that forever (for example, see this US cavalry manual [ibiblio.org] which stipulates cavalry can go 35 miles a day, six days a week indefinitely - page 152) while the person would not be able to maintain that sort of pace for more than a few hours to a day unless they were in really good shape.
In comparison, typical indefinite marching rates for an army were about 10 miles a day [0catch.com] (both for roman legionaires and US soldiers).
horses weren't common and stopped the spread (Score:4, Informative)
Almost nobody had horses back then, compared to the 19th century. Working the land was done manually, or with the aid of oxen and such. Horses were more or less used as battle transportation and sometimes very important couriers. There was occasional other use for them, but horse ownership was usually reserved to the nobility and rich cities due to the cost of maintenance in the times that the black plague was hitting Europe.
Keep in mind that the black plague was spread by fleas that favoured rats, cats, dogs and such as hosts. They would choose humans as hosts, but were repelled by horses and their smell. As such, people that lived in horse staples and worked with horses, or rode them to the next town, most often were spared. If a lone person travelling on horse back would come from an infested city and was not bitten by an infested flea by the time he left that city, he wouldn't be carrying any infested fleas or the bacteria by the time he arrived in the next town. The spread of the virus might have actually occurred without any human interaction whatsoever in a lot of cases where fleas just infected rodents living in the wild, or actually by people that travelled by foot and brought their dogs and such along.
Re:interesting question (Score:5, Informative)
Have you got any good readings you can recommend on the subject =)?
Registration and Purchase required? PDFs from the New Cambridge History of Islam. There's an amazing maritime section here:
http://universitypublishingonline.org/cambridge/histories/ebook.jsf?bid=CBO9781139056137 [university...online.org]
Blow your mind, with the journal of the travels of 14th Century adventurer, Ibn Batutta. He makes Marco Polo look like a homebody.
https://en.wikipedia.org/wiki/Ibn_Battuta [wikipedia.org]
1929 abridged translation of Ibn Batutta's journals:
http://books.google.co.uk/books?id=zKqn_CWTxYEC [google.co.uk]
More books? Warwick Ball is an accessible archaeologist and historian, who effectively destroys the case for "Clash of Civilizations", and the entire dubious taxonomy of "east and west".
http://www.amazon.com/Rome-East-Transformation-Warwick-Ball/dp/0415243572/ref=sr_1_1?s=books&ie=UTF8&qid=1382201303&sr=1-1 [amazon.com]
http://www.amazon.com/Out-Arabia-Phoenicians-Discovery-Europe/dp/1566568013/ref=sr_1_5?s=books&ie=UTF8&qid=1382201303&sr=1-5 [amazon.com]
http://www.amazon.com/Towards-One-World-Ancient-Persia/dp/1566568226/ref=sr_1_3?s=books&ie=UTF8&qid=1382201303&sr=1-3 [amazon.com]
Nice, "pro-Nabatean" writeup on the late-antique origin of Arab maritime trade, after the breakup of Alexandrian east. You will have to go farther back, to the Phoenicians of Tyre and Carthage, 'tho! This author begins with Nabatean emergence. There are many links on this site... Quite fascinating.
http://nabataea.net/who1.html [nabataea.net]
Oman and maritime history. Nice to overlay this with the Nabateans. These things met and mingled - especially out in the Indian ocean, away from home:
http://www.maritime.om/Oman-Maritime-History [maritime.om]
The sections on Ancient Indian and Chinese maritime development is slim, but worthwhile:
https://en.wikipedia.org/wiki/Ancient_maritime_history#Indian_subcontinent [wikipedia.org]
An Indo-centric, but factual and entertaining page:
http://www.aseanindia.com/navy/maritime-history [aseanindia.com]
Summary of "silk-routes":
http://www.silkroutes.net/SilkSpiceIncenseRoutes.htm [silkroutes.net]
Genoa in the Crimea:
https://en.wikipedia.org/wiki/Genoese_colonies [wikipedia.org]
Technology of early Islamic ship-building - mostly focused on Mediterranean, not Indo-Persian
http://www.academia.edu/1596791/Early_Islamic_Maritime_Technology [academia.edu]