-Scientific Progress Snip-
What a load of loving stuff.
The idea that the "Dark Ages" was a movement backwards in scientific knowledge is complete hogwash.
Europe became a significantly more fractured location, but things weren't entirely forgotten.
Lots of scientific/mathematical knowledge was simply held by the few, such as the monasteries and the Church, rather than the everyday man (which was just as common as it was in the time of Imperial Rome or Ancient Greece).
Science progressed significantly in the medieval period. Siege warfare and architecture improved to a considerable extent, as did weaponry (the English longbow and the creation of cannons are just some examples of this).
Ship building underwent a monumental transformation, particularly as ship-travel expanded into the Atlantic Ocean, which ships being used by the Spanish/English/French around the Bay of Biscay and the English Channel, where Classical Mediterranean boats would not have been capable of working effectively.
The Printing press was produced in Europe in the Medieval period and laid the way for the Renaissance.
The Dark Ages is a terrible misnomer applied to the Middle Ages, and it's just incorrect. While we have a smaller amount of written account from the period, it in no way means that the world didn't progress.
Even today we learn of new literary sources for the period. "The Dark Ages" is a term coined by the Victorians, who didn't have the skill or education to find what we found today, and failed at their time to find as much information on that period.