I wouldn't call them sci-fi, aside from being transported to a different dimension. Herro of Alexandria was said to have built a steam engine, but nobody had any idea what to do with it...it was just a neat trick to impress kings and stuff.

He also made massive temple doors that were opened by steam. You'd light a fire on an alter, it would heat a hidden water tank, the steam would push the lever that released a counterweight just heavy enough to move the precisely balanced doors.

Also, the Antikythera mechanism was found in a Greek shipwreck from the same time. Some people think it was used to calculate the movement of the planets, but it was essentially a very complex clockwork computer made of dozens of intertwining gears.

I think as a lot of the repliers have mentioned its hard to say how advance the Dwemer were using reality, (realistically speaking), comparisons. Though I think they were advance, far more than the other races in the Elder Scroll Universe in one aspect, which has only been repeated by very few; those few being individuals rather than an entire race as a whole. Namely they did not fear the Daedra, and such in Lore a lot of the Daedra hated the Dwemer but where powerless against them for reasons that weren't wholly explained, (Azura did change the entire Chimer race into the Dunmer for disobeying her, while as the Dwemer were vastly more insulting to the Daedra as a whole), considering the nature of the Daedra; Molag Bal comes to mind, they would have surely attacked the Dwemer, either by being summoned to do such a thing or through other means. Since their destruction was caused by their own hands, unlike the other races they didn't fear the Daedra and rather were able to somehow prevent any attacks by the Daedra despite the other races respect of the Daedra themselves.

Noticeable people who limited the Daedra in some manner, the Tribunal (stole divine powers) they being some of the more well known that fought the Daedra, and in case of Alm and Sil they fought Mehrune Dagon personally. Martin Septim using the power of Akatosh was able to send Mehrunes back, though out of the majority of people some I haven't named most had divine assistance and based on Lore the Dwemer didn't rely on Divine power till their destruction, (ironic since they were attempting to create a God that would could give them Divine protection) So they were advance to the point in which where as other races, have fallen upon using Divine power to repel the Daedra in what ever instance that might have arouse, they generally used their own power as a race to hold back the Daedra.

In a world made of magic, technology is of necessity magical.

For that time set yes they are quite advanced.

That metal god would have been powered by the heart of a real god, however. And that battery was the most important part. The Dwemer would not have been able to take full credit for Akulakhan if he'd ever been born. He'd have been Lorkhan in a shiny new package.

A shiny, disease looking package.

Numidium= shiny package (courtesy of the entire Dwemer race)
Akulakhan= disease looking package

Hence Akulakhan being the shiny new diseased package for Lorkhan.

What exactly is Tonal Architecture? I remember the Morrowind MQ talking about striking the heart and producing a pure tone as part of the process used in patterning or whatnot to create the Tribunal. You refer to it as a language--is it a language, or is it something that creates a divine substance? Is it the "divine spark" that the lore sometimes refers to?

Lorkhan's [body] was cracked asunder and his divine spark [Heart] fell to Nirn as a shooting star "to impregnate it with the measure of its existence and a reasonable amount of selfishness."

Lorkhan's Heart was the divine spark. Tonal Architecture is the pattern of mythopoeia, which is the narrative of the universe. I mean it is like a Divine language, having a consciousness of its own (Metafiction). Language is a system of unity and identification; and the Tonal Architects were a faction dedicated to unifying their race and reversing spiritual decay, through manipulation of this invisible tapestry.

Too add an example from literature, using the beginning of the Silmarillion as an example, the dwemer knew the song that created everything, and tried playing it themselves in order to reverse time and become a god again.