Saying the Romans "could" do something doesn't mean much. Roman and Viking ship construction was different, while the peoples of the Med. were likely better navigators overall, they didn't typically build ships for that kind of travel. And as for the Romans being in the Canaries that's not really surprising they had trade outposts in Southern India/Ceylon/ likely even further east. this can all be reached however without having to across a massive basically empty ocean.
There just isn't much benefit of putting the Americas in, there was very little of import going on. And even if we started buying some very outside theories of trade between Europe and Americas, by your own evidence it was so small as to be utterly inconsequential.
Actually the Viking ships are derived from the Liburnae Roman ships that Romans used in the northern sea fleet . Also Romans did have fleets also inocean they did not just sail the mediterranean , they had regular Atlantic fleet that went up to Scandia and Hibernia as well as Indian Ocean fleet that went up to India , there are roman comercial outposts everywhere.
From Canary islands there are too seasonal winds that bring right to Americas . Also Romans , had Already an Astrolabe, it was then later inherited by Arabs when they took over the classic world as it was a sudden introduction by when they conquered the lands and they never were a seafaring people.The first major writer on the projection was the famous Claudius Ptolemy (ca. AD 150) who wrote extensively on it in his work known as the
Planisphaerium. There are tantalizing hints in Ptolemy's writing that he may have had an instrument that could justifiably be called an astrolabe. Ptolemy also refined the fundamental geometry of the Earth-Sun system that is used to design astrolabes.
Do not underestimate Greek and Roman civilizations, they were far more advanced that thought today and if we do not know much is only because 90% of the ancient text went destroyed with the Islamic invasion of the north and east empire as well as the Germanic invasions . New discoveries are made once in while that forces us to rethink about them As shows the
Antikythera mechanism.
My Point is not to prove that Romans , greeks or may be even Phoenicians went to Americas but that its a very possible probability. Even in Roman age there were reference of some Indians coming from the Americas that were dropped from a Storm on the European coasts.
"The same Cornelius Nepos, when speaking of the northern circumnavigation, tells us that Q. Metellus Celer, the colleague of L. Afranius in the consulship, but then a proconsul in Gaul, had a present made to him by the king of the Suevi, of certain Indians, who sailing from India for the purpose of commerce, had been driven by tempests into Germany." Pliny the Elder (Natural History 2.67)
Unfortunately its all fault of the 90% lost classic works... how more enightned we would be on our history if those were not lost

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