In 1492 Columbus sailed the ocean blue. But why didn't the Romans, in all their centuries of expansion, ever make it that far. Was their some particular technology that enabled Columbus to make the journey that the Roman's (or any ancient European civ) didn't have?
Well I think the main reason is that the Romans simply were not heavily invested in nautical exploration, or exploration of any kind that wasn't politically, finically, individually, or militarily motivated. They primarily had ships for trade and as a means to wage war on land in and around the mediterranean. They are known to have contact and trade with the far east in Asia and China, but these routes and contacts were largely pre-established by other countries or peoples. The Westernmost region of the Republic/Empire was Britain, which they tenuously ruled between 43-410AD, never fully taking control of the whole island. The initial invasions struggled crossing the channel, and resulted in multiple attempts at invasion. They really were not a strong sea-faring people.
A big part of political prestige was having command of legions and being able to conquer lands. Cesar, Mark Antony, and other politicians sought command of armed land forces to bolster their power. Rome lies inland, with its main port located in Ostia, 25 miles away. A later port was made in Civitavecchia, 51 miles away. Having naval supremacy is incidental in Roman internal politics because its an ineffective threat. As was the case in Carthage, Greece, and Britain they would prefer to use ships to ferry their forces, and fight on land where they were most effective, rather than try to wage war at sea.
Carthage was the dominant naval force in the mediterranean and during the 2nd Punic war in the mid 200s BCE the Romans rather than try to best them at naval conflict tried to negate Carthage naval might by equipping their ships with hooked planks so as to allow their ships to come aside, launch the planks, and to board the enemy ships, thus avoiding naval tactics. They lost the battle, and then took things a step further in the following fight by just building their ships with rams, and smashing through the Carthaginian ships! By defeating their main maritime threat, they became the new champion of the seas, but had no real reason to expand their abilities at sea because there was now nobody to fight.
Rome existed in a near constant state of conflict and war. From about the year 300AD onward things got progressively worse and is referred to The Crisis of the Third Century. More and more invasions and internal turmoil led to the founding of Constantinople in the 330s, and the division of the empire into the Western and Eastern halves. Finally the Western empire fell in 476 to Germanic gothic invaders and the former western provinces of Rome fell into their own warring states, thus essentially preventing any further Western expansion. These invasions were land based so there was no value in having a strong navy mercantile, military, or otherwise.
The following centuries see the continent in a state of upheaval as the dust settles. Germanic/gothic tribes vie for control of the region as well as the Iberian peninsula until the 700s when Slavic tribes move through central and south-eastern Europe and the Moors invade Spain. The Frankish tribes are united in the west/north west in the 480s and convert to Christianity. They continue to expand east until the 800s. The Norse/Scandinavian vikings commence raids and expansion west/southwestern with raids of the British Isles. There isn't a group of people or country invested in exploration until the Norwegian vikings settle Iceland in the late 800s.
The Norwegian vikings went further west in the 900s and settled Greenland. They reached North America (they called it Vinland) in present day Nunavut, Newfoundland, and New Brunswick in Canada nearly 500 years before Columbus arrived in the Americas. They left behind a settlement called L'anse Aux Meadows that wasn't discovered until the 1960s. The reason for their expansion at this point in history is not known, though several theories exist. They are said to have had clashes with the Franks, and be aware of their new growing power, possible population issues due to, female infanticide, limited living and agricultural space, and the advancement of their shipbuilding technology. They were adept sailors due to the abundance of waterways that permeate the region. The British isles were in a constant state of flux and war, which left them as easy raiding targets.
Tl;DR:
Hey there,
Just to let you know, your question is fine, and we're letting it stand. However, you should be aware that questions framed as 'Why didn't X do Y' relatively often don't get an answer that meets our standards (in our experience as moderators). There are a few reasons for this. Firstly, it often can be difficult to prove the counterfactual: historians know much more about what happened than what might have happened. Secondly, 'why didn't X do Y' questions are sometimes phrased in an ahistorical way. It's worth remembering that people in the past couldn't see into the future, and they generally didn't have all the information we now have about their situations; things that look obvious now didn't necessarily look that way at the time.
If you end up not getting a response after a day or two, consider asking a new question focusing instead on why what happened did happen (rather than why what didn't happen didn't happen) - this kind of question is more likely to get a response in our experience. Hope this helps!