What is now called Russia started around 850-900 time period, which is near the middle of the Dark Ages shown in the graph. The graph correctly indicates the Dark Ages time period, and does correctly reference the regression of technology as a result of the Dark Ages which were initiated by two primary factors: the fall of the Roman Empire and Christianity. At the early times of Christianity(c.30-400) technology continued to advance under the Roman Empire, which was highly focused on technological advancement, similar to our current civilizations and indeed had universities for higher learning and scientific research. This prosperous period continued as Christians during the Apostolic Era were persecuted by the Romans and Christianity had a hard time getting started.
In the post-Apostolic Era(after the Apostiles died, roughly 100 AD) the persecutions of Christians was sporadic and often resulted in large executions or martyrdom of prominent church leaders. For roughly 200 years following this there were still sporadic persecution with Christians but Christianity was growing. In 313AD Constantine 1(Constantine the Great) and Licinius issued a letter named the Edict of Milan that proclaimed religious freedom in the Roman Empire.
During the 4th century the Christians began a rise to power and were more predominant in the Western Roman Empire. In 476 Odoacer became the first King of Italy, the former Western Roman Empire. This is the demarcating event for the end of the West Empire and the transition from Antiquity period to the Middle Ages(Dark Ages). At this point the church had gained a fairly substancial role in daily life and had quite a bit of political power. In the early ages many new technologies and some pre-existing technologies were frowned upon by the church and were removed from regular use. This represents the technological regression experienced during the Dark Ages.
It is extremely important to note that this period of regression only happened in the Early Middle Ages and represents a small part of the Middle Ages. After this period of regression technology was stagnant for a period of time, due to a number of reasons. Due to the fall of the Empire, a large number of habitants became nomadic and moved to different areas. Any type of 'government' funding for scientific research was non-existant. People were content to focus on their daily lives and make a living.
During the middle and end of the Middle Ages(Dark Ages) it was common for people to be encouraged to have rational thinking. To follow a theory to its logical course. This is what set the ground work for so much scientific advancement. While there wasn't a huge amount of advancement during this period(as referenced in the graph) the ground work it laid is equally important, and was encouraged by the church.
There was a much larger and more predominant role of the church in declaring scientific research heretical and ex-communicating church members immediately following the end of the Middle Ages than there ever was during the MIddle Ages. Most people are familiar with the stories of Galileo Galilei being forced to recant and live under house arrest for the remainder of his life.
So to sum it all up, the state now known as Russia did not exist during this period of scientific and technological regression and was actually founded by descendants of the nomadic peoples displaced by the fall of the Western Roman Empire. There is no existing state that was not either involved in the Roman Empire, or influenced by the Roman Empire and thus the fall of the Roman Empire existing today, so there is no comparison for what the Dark Ages did to technology. The best thing you can do is estimate based off the fact that the period of no technological advancement or little advancement lasted for nearly 600 years, and then took nearly 400 more years before scientific research was widely encouraged and accepted again. Add it all up and you had nearly 1000 years of time in which we could have been advancing technology had the Roman Empire not fallen. Likewise, what people would not have been born that are credited with major advancements that might never have happened had the Roman Empire not fallen.
On a separate note, it is also important to note that scholars since about 1900 have no longer used the term Dark Ages, and only use the term of Middle Ages. The term Dark Ages was used to label the period of time between the fall of Rome and the Renaissance era. Likewise the term Middle Ages has a similar application, representing the period of time between the end of the Classical Antiquities era and the beginning of the Renaissance era.
Feel free to inquire further about any of this. This is a period of history that I absolutely love reading about and watching documentaries about. Absolutely love anything starting the the Romans and going forward. Also love military history of any age.
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