The Romans actually had a protoype steam turbine right around when the New Testament was written.
Not really, what they had was a steam toy. There were some slightly more complicated designs used to open doors at temples using stean and counterweights, but even then they would never consider a machine like that to to do labor, it was a tool for magic. It would be impossible for Romans to make actual steam engines, they the thousand years of improvements in metalurgy made during the Midaeval period that were required to not have your steam engine not explode on you if you made it do actual work.
Heron's invention was really just a demonstration piece, as
@Doomsought said. It should be noted that such fanciful inventions were also very much a Greek thing. It's something of a generalisation, but the Greeks were more interested in the science for its own sake, and the Romans were more practically-minded and tended towards a focus on engineering.
(Regarding knowledge being lost, whih got mentioned in this discussion: that did happen. We have examples of Roman notes on Greek scientific texts where the -- educated! -- Roman commenters clearly just don't grasp the complexities of the Greek maths. But note that it's amost always like that: theoretical understanding is sometimes lost, but practical knowledge -- the "know-how" -- is almost always retained.)
None of the knowledge was lost, just the budget for large infrastructure projects. That is why technology during the Medieval period expanded more towards getting more done with less resources.
So this holds up. Although, again, actually a
lot of classical knowledge was lost. And had to be re-discovered from the Greek later. But again, it wasn't the
practical knowledge that got lost.
They didn't follow through with that development becasuse "What do we do with all of the slaves?" was a question they didn't have an answer for.
This is just incorrect. The Romans never asked that question (nor did the Greeks), and in fact the owners of the larger latifundia (who were the big slave-owners) were typically the
most interested in technological improvements that made their systems more efficient.
Until you get to really modern precision-work, slavery can easily be used in mines and in workshops
just as well as in the fields. In fact, if the conditions are right, slaves can be used in very modern contexts, too. Consider who physically puts together the iPhones
right now. Most of those poor sods aren't formally slaves... but only because that's cheaper for their bosses. Having to actually house and feed them would be more expensive than the few dimes they get as a salary. (Not to mention the prisoners used for brutal slave labour in China, of course.)
Which all goes to show: slavery doesn't impede the development of a modern, technologically advanced economy. On the contrary: modern capitalism tends to just make slavery obsolete... because slaves are simply too
expensive. So freeing them and then hiring them back for a pittance is just cheaper than keeping them as your property.
en.wikipedia.org
