It's likely that the greater forces responsible for the downfall of the Roman Empire would have happened regardless of what advanced technology they might have developed.
What happened is that regions progressively became more independent and broke off from the central hegemony of Rome and then Byzantium. It took until the 1400s for that last official centre of Roman power to dwindle, and even through to today, Rome has maintained a huge influence on the rest of the world through the Roman Catholic Church.
So, rather than falling down, the Roman Empire slowly but surely transformed into something else. Arguably, we (western civilisation) are the direct descendants of the Greco-Roman Civilisation, and so one could make a (somewhat strained) argument that the Roman Empire is alive and well today, just in a different, more modern form, that has undergone 2000 years of evolution.
What to make of this myth of the downfall of the Roman Empire, the Dark Ages, etc? Well, according to that lecture series, this was largely a myth concocted during the Enlightenment to position it in history. The Renaissance needed to frame itself as a major cultural change, so it helped to frame history as "the Classical period, the Dark Ages, and now the Renaissance" - and draw on a fine period of history to support all the new ideas and revolutions brewing (i.e. "things were good back in Roman times, then things were really bad because of the Church, and now things are better again because we're standing up to the Church"). For the people living through the supposed transition between the Classical Period and the Dark Ages, though, apparently, there was no such stark difference.
200-350 : serious decline and infighting, split into four regions, during this period attempts to enforce price controls to stem inflation. Rome itself stopped being political centre
350-400 Constantine recovery (unites to one region again - one empire of three parts, one god of three parts, one emperor - gettit?)
400 + : total collapse of western empire - communications fail, smaller regions contest with each other, and inflation wrecks the value of economies as trade collapses. Eastern empire carries on with vastly reduced army and trade links to Persia.
This really was a dark ages - impoverished, illiterate, backwards looking and lacking trade with most of the world. There was no single definition of dark AGRs - mostly because there are few ways to be right and many ways to be wrong In short, the glory of empire did not last as long as everyone thinks - mostly Rome was a trade agreement that everyone else was keeping up in lieu of anything better.
And it was not really a dark age. As I said in my previous post, the dark age narrative is largely an invention of the 17th-18th century. What actually happened in that period was the development of a whole lot of great stuff like city states, art, commerce, banking, kingdoms, navigation tools (compass), military inventions (crossbows, guns), hourglasses, farming technology (ploughing), metallurgy, optics (eyeglasses!), mechanical clocks, textile technology (spinning wheel), the printing press, windmills, glassmaking...
For the people living in those times, it probably didn't feel anything like a "dark age". Just a fairly smooth progression upwards, with the usual ups and downs of wars, plagues and other disasters that are hardly confined to the middle ages.
I know the narrative of "here's the awesome roman empire, and now the church takes over and you have the dark ages, and now reason comes back in the form of the renaissance" is very compelling, particularly if you don't like the church very much, but it is just a narrative, and is not very well supported with facts.
Taking 1066 as a uk centric cutoff much of the above had either not been invented / rediscovered
Kingdoms and city states - The Roman Duc and knightly organisation of armies appeared before 350, banking was I thought super charged by the crusades. Compasses - Marco Polo, the Mongols, guns - not till what 1300?
I am aware there is always some in Europe knew but it did not benefit most.
So it does depend in definitions (as always). If its the simplistic Romans/bad church/good renaissance then yes I agree with you, but if it is Good Romans/messed up Romans/dark ages/Europe starts to join the world/renaissance Then I am much happier to argue for a period of 400+ years where development in Europe was largely static and the agrarian based economies just slowly adjusted to lower levels of trade etc, and certainly 450-550 was just a morass of backwards sliding.
It may be because I am more rushed on the phone, but I suspect it is a function of how I think - I seem to think by typing and my typing speed on Iphone is much slower than my brain can handle
In my view the Dark Ages were a rolling back of the benefits of a continent-wide peaceful trading bloc and a scramble to find a non-anarchic equilibrium from which everyone could rebuild. The multiple sackings of Rome however really made contemporaries realise Rome had fallen (and probably drove everyone to look for a solution closer to home - just the wrong move in Economics 101)
Will it happen again - pretty likely. We are on a growth treadmill - the Romans growth fed by an seemingly inexhaustible supply of slaves from conquered regions, that dipped after Tiberius around 110.
And us. Well we have machines to do all the work for us - on average a UK citizen burns up 120kw per day - or 40 slaves burning 3000 calories a day. We need to keep inventing more efficient machines or inexhaustible energy supplies
So make room temperature fusion work and I will say its unlikely we will collapse. Without it, probably inevitable - but we keep going, because the poor are starving and the Syrians are getting shelled.
That's interesting thought you have though, of building society on "energy consumption" (labor, work, joules, whatever) whether it be slaves or oil. I suppose you could say it boils down to physics.
The first wood burner must have halved the energy needed to keep warm - probably the best investment society made ever.
Of course energy efficiency as a metric Must make bankers even less useful to society than we think :-)
For example I live in the Lower Danube area, from where the Romans retreated around 275 AD. Reading about the near-by Roman city of Ulpia Traiana Sarmizegetusa (http://en.wikipedia.org/wiki/Ulpia_Traiana_Sarmizegetusa) it's surprising to see that only 2 generations after the retreat of the Romans the local people would revert to living in sunken huts, oftentimes a stone's throw away from the ruined Roman villas. The same people probably also lost the art of writing, because in the case I'm reading about there are no written documents or stone-graves or anything that could attest to the fact that they knew how to write for more than 700 years.
The thought that this kind of things could happen again should be on the back of our minds. For example I'm a little bit worried that more and more information about our civilization is only stored in electronic format. It suffices for us not being able to produce electricity for like 2-3 weeks and all of this will get lost.
Yes and no. Roman decline really happened, but the significance attached to 476 AD is an artifact developed later, when the decline actually happened over hundreds of years. As you noted, the Eastern Roman Empire carried on for another thousand years, and the Catholic Church remains the largest religion in the world.
There was a decline in trade complexity, literacy, and probably standard of living at the top of society. Medieval historians did believe they were in a time of decline and ruin (this was heavily influenced by Christianity and its apocalyptic prophecies) but the average Germanic peasant didn't know enough to care either way, and probably had no substantial change in his material well-being from 100 AD to 600 AD (or 1700 AD).
One of the things to keep in mind is oblique comparison. Most people who perceive decline compare their status to that of elite people in the past, creating a sense that things were better then. You'd certainly be better off as a Roman patrician than as a peasant in 7th-century Bavaria, but that's not a proper comparison.
From the perspective of a literate elite, there was civil and industrial decline, explaining the impressive infrastructure that had fallen into disrepair. For the average European, there probably wasn't a directional change, but the average European left no writing.
Would it be fair to say that the average rural worker since the invention of farming had a sh*t standard of living till sometime in 20th century. It is just the upper levels of society that saw and benefited from swings in civilisation.
Interesting.
PS: The roman army was great for it's time, but they would have been decimated by far smaller 'dark' age equivalents. The closest real world comparison was Hernán Cortés and the fall of the Aztec Empire using 6 guns ~2,000 people, 100 horses they could easily take on the euqivelent of an 100,000 man incan army. (Incan army was larger than that but they had native help.) http://en.wikipedia.org/wiki/Hern%C3%A1n_Cort%C3%A9s
War, as you've noted, is one thing that medieval Europe was (compared to the Romans) quite good at. There's a misconception that European swords were heavy, awkward, and dull. While they were never as aesthetically attractive as Japanese swords, they were formidable and more than good enough to do the job.
The average European went from a free citizen of Rome to a serf, laboring under conditions that bordered on slavery. I'd say that's a pretty radical negative change.
~30-40% of the population of Roman Italy was made up of (real) slaves and most Europeans did not have Roman citizenship until so late in the Empire that it didn't really gain them much (it was actually disadvantageous to most -- Caracalla only instituted universal Roman citizenship so he could raise the taxes on the new "citizens").
I agree that serfdom wasn't much better. IIRC, one of the few advantages of serfdom was that you couldn't (in general) be sold away from your family. Serfs were considered part of the land.
One of the big changes with Rome was that at some point, they became too big. Earlier in Roman history, the Romans would either kill everyone (Ceasar's conquest of Gaul killed a substantial proportion of the population) or begin a process of Roman-ifying the populace. The Roman armies kept the peace and spread the civilization.
The problem is that you had this built-in tension between keeping Rome (the City) under control, which was extremely challenging, and keeping the provinces in line and secure. Emperors had to spend fortunes subsidizing the City with grain, festivals/circuses and other support. Getting those fortunes meant levying onerous taxes, and collecting in the provinces meant enpowering the local Roman officials and military -- which in turn created rivals to the emperor.
Another issue is that as time went on, gaps in agricultural technology fundamentally changed the society. The core of the Roman republic was citizen solders and civil servants -- many of which were yeoman farmers. As crop yields declined and demand grew, these farmers went out of business and consolidated into much larger estates that were dependent on slavery.
All of these things resulted in changes to the character of the Roman system. Roman armies were not made up of Romans. Roman generals were not necessarily loyal to Rome. It just turned into a big mess.