Many years ago, a book came out…it was called “THE DIFFERENCE ENGINE”. It was novel, set in the 1870’s…the main theme was that the digital computer had been invented back then. Others have speculated on a steam engine in Roamn times…but suppose Rome had invented firearms/gunpowder in the 3rf century AD. What would things be like today-would we have skipped the whole nasty Middle Ages? Perhaps we would have colonized Mars by now?
Of course, wemight well be under the thumb of Emperor Augustus XXV!!
The Printing press.
In Rome.
Or Classical Greece.
The greeks had all of the information and even technology to make a steam engine…and never did more than play with it as a toy. This was even before Rome. Also, they had working knowledge of the battery, but never developed the technology or expanded on it. If either of those inventions (but especially the steam engine) had been developted it would have radically changed history IMO.
-XT
Egypt also was on the verge of building some serious technology. Apparently they too had battery technology and may have constructed an arc lamp.
We forget, however, just how much technology needed to be invented along the way. Here’s an example: In Roman times, to plow a field they would just throw a rope around the ox’s or horse’s neck. It choked the animal and was inefficient. It wasn’t until the Middle Ages that a proper yoke was devised.
Etc. I often wonder, though, what little inventions (or big ones) lie just beyond our sight: things like paper clips, Post-It notes, etc.
If only Lincoln had been able to phone in a pizza, he might have skipped the play and stayed home.
However, we have to remember that inventions and technology do not neccesarily mean the beginnings of an industrial revolution. The Chinese had gunpowder, the printing press, etc, etc, all long before Europe. However, the technology didn’t inspire a revolution, it mostly didn’t change anything. Gunpowder caused a social revolution in Europe because it evened the scale between the peasants and the aristocracy. However, the social structure of the Roman empire was different. Arming the legions with matchlock muskets wouldn’t threaten the status quo, it would reinforce it.
I don’t know if that’s necessarily true. From what I understand, ranged weapons tended to be either mercenaries fighting for pay or auxilliaries drafted from the populace to fill that role. Would the typical legionaire have been willing to put down the pillium and pick up a rifle? I tend to think not… eventually you would have had a sizeable number of trained rifleman (arquebus, whatever…) that were still looked down on by the aristocracy…
Vox populi et gun… hehehehe…
If you give homo sapiens modern inventions, you get what we have now. My jaundiced opinion is that if they have them long enough, they’ll wipe themselves out. So I guess my answer would be that if the ancients had had modern inventions, we wouldn’t be here.
The third century is ancient times.
How about the compass and big sailing ships? I have never seen a technical reason why the Greeks or Romans did not have them. I suppose they just never saw a need.
The same can be said for the technology required to construct the early Wright Gliders. The Greeks and Romans certainly could have built one had they recognized a need. Hell, they didn’t even have toilet paper!! Now there is a need!!
Perhaps our descendents 2000 years from now, will ponder as to why it took so long to invent or discover the many things that they will be utilizing as common everyday items, all using technology that existed in the 21st century.
…“was” ancient times. 
Quit bitin’ my style. 
"If…if…if… Ain’t it fun?
If ‘ifs’ and ‘buts’ were
‘Fruit’ and ‘nuts’
We’d all have Christmas
Every day.
The original question seems to boil down to: “If modern technological achievements had been available much earlier in the history or mankind, would the impact of this technology itself have significantly altered subsequent history?” We have historical examples (the longbow leaps to mind) where the introduction of a new technology has produced a result which appears to change what had been perceived as a natural or expected outcome, and I don’t know where all these scifi writers would do if the answer to this question were a resounding “no”.
However I’m going to offer a contrary view. Technology is more than just the artifact itself; they are a product of the necessities and attitudes of their times. If the Romans had adopted rifles, for example, this would mean they (1) clearly saw a need for its use, and (2) accepted the industrial-revolution-era ideas necessary to make a mass arming of the Roman legions feasible.
Regarding (1), we have examples from history of inventions that were rejected at the time they were proposed. Revolutionary inventions like telegraphy and wireless, for example, was demonstrated much earlier than when they took the world by storm (telegraphy predated Morse by some 50 years). And although the Chinese invented gunpowder, but it didn’t change the course of history until the West saw the military applications.
As for (2), I can speak only of examples from Roman history. During the construction of the Colliseum, a proposal was made to use extensive cranes to speed up the construction. Vespasian, I think, nixed the plan because he wanted to employ as many people as possible on the project; the attitudes of his day did not see the benefit of such a labor-saving device, a tenet of a more modern age steeped in post-industrial culture.
This isn’t to say the Romans wouldn’t see the advantages of using rifles in warfare. I’m merely stating that they might not have the wherewithal to systematically adopt its use.
I’m sure a lot of people on this board have read Guns, Germs, and Steel by Jared Diamond. He notes that China developed a large number of technologies long before they arrived in Europe, yet Europe still gained technological and military dominance. Similarly, he notes that feudal Japan did recognize the usefulness of firearms and began building large numbers of them. In China, it seems that the millenia-old tradition of a unified Chinese government (starring Jet Li as the Nameless Hero 
) allowed the central authorities to suppress technological development on a whim without anyone else being able to stop them. And once it was stopped, it was very difficult to get it started again. In Japan, the samurai class realized that guns would allow untrained peasants to blow them away, so they too suppressed this technology. Of course, that all changed during the Meiji Restoration, when Japan was forced to hire Tom Cruise to train peasant armies to use guns. Why didn’t this kind of thing happen in Europe? Diamond says it’s because Europe was composed of a lot of small, competing states that had neither central authority nor relative isolation. If one European prince decided to outlaw guns, all the neighboring countries who had guns would quickly convince him this was not a good idea.
I think the real reason that Rome was technologically stagnant, was that no university system ever emerged to transmit intelligence! Take mathematics: at the end of the Roman Empire, we had the last great mathematician of antiquity (Pappas of Alexandria). As every 1st year calculus student knows, Pappas had all of the necessary fundamentals to have invented the calculus…but his brilliance was lost, because he had no university to pass his achievemnts on. Likewaise with physics…no science of mechanics emerged in the late Roman empire. Sure, a genius came along every few years,but he could only work alone, and had no way to try out his ideas with other geniuses.
So, for all the horor of the middle ages, at least they started the university system, and allowed new ideas to be transmitted to a wider audience!
Modern inventions DID come about in ancient times.
What I mean is, at some point inventions were going to start building on each other so rapidly that there is a sort of a technology explosion. You could think of Greek geometry or the Internet or some other marker between them, but the question is a weird one because we ought to think of ancient versus modern as being defined by the technology explosion.
But that’s not what anyone meant, right?
How about this: it was a sort of accident that the Age of Christ got rolling before the technology explosion, and we can easily imagine if that religious movement was a few hundred years later in starting and if, maybe, printing got started a few hundred years earlier, well, lots would be different.
Ah, but there are other theories about why the technology explosion happened when it did. One of them says that human slavery practiced by Greeks and Romans reduced the incentive to reduce labor through technology, and it was the Christian sanctity of life that reduced slavery to the point this was changed. Another says that the increased opportunities associated with population thinning in Europe during the Black Death was the trigger. I think mini ice ages are another theory.
The Chinese saw the military application. They used cannons for sieges. The Mongols were the first ones to use artillery in Europe.
It’s just that the needs were completely different. You don’t have much use for artillery if you’re chasing down horse riding nomads 1000 miles from home. Now, if your military goal is besieging a town or castle 50 miles away, a cannon becomes a God’s gift.