Have you noticed that throughout a period of almost a thousand.. no wait.. like two thousand... wait.. does the dragon break count? aw whatever. I swear, TES's timeline is just a fritzed up mess...
Anyway, Throughout a period of about 2000 years, the technology of TES has not changed much. Why? Why not? I'll get to that later.(the why not part)
Why?
I dont know to be honest, i mean it's been 2000 years and its in the Renaissance era, but without any sort of gunpowder weapon. Not to mention the lack of any sort of advanced machinery except for this particular instance:
(spoiler alert)
http://www.uesp.net/wiki/Oblivion:Infiltration
But really, shouldn't TES be at least in the steampunk era? No. I'll tell you why.

Magic.

Magic?

Yes, Magic.

The main reason we humans have so much technology is because we have a desire to heal our friends, kill our enemies, and be lazy. Thats why we have so much tech, like medicine and guns.
But TES's humans dont need that. They can heal themselves with nothing but their will, and use it as a weapon as well.
So there was no real need to study physical science, as all the healing and weaponry (save for melee weapons and bows) is satisfied by magic.

Just something interesting i thought up.