Was there any (significant) technological development during the Third Age

Question

The Third Age lasted about 3000 years. In The Hobbit and The Lord of the Rings we see the last years of it and Middle-earth is in something like a "dark age".

The human empires are either destroyed or have lost their power and large cities are completely abandoned. The Elves are still magnificent, but in state of decline. The Dwarves remain passive with the reclaiming of Erebor their only high point since the fleeing of Moria.

From technological point of view there is a complete decline in weapons and architecture. We see weapon technology in both books and all the best weapons/armor are ancient ones. We also see architecture (in the form of the great monuments and cities) but all of them were created in ancient times. The current state is that everyone is using/admiring these masterpieces but no one is even close to being able to build the same thing (or something better)

So - was there any technological development during the Third Age?

Answer 1

Tolkien got much of his 'the world used to be so great, and now everything is going to hell in a hand-basket' worldview from George MacDonald's The Princess & Curdie (sequel to The Princess & the Goblin, whence Tolkien got a significant portion of his concept of orcs/goblins), so you are definitely onto a theme of decline (including technological, but also spiritual as in the fading of the Elves, and Men's loss of Númenor).

That said, a few technological advancements seem to have occurred since the previous ages: these are agricultural or the products of agriculture (particularly the results of fermentation):

• Cheese—is not mentioned that I recall in the writings of earlier ages, and may require a significant social organization and variety of production and storage technologies.
• Beer and wine—also not mentioned that I recall in writings from earlier ages. Beer and wine-making also require social organization, production and storage technologies.
• Pipeweed—Notwithstanding the mystery of tobacco in the Old World before the late 15th/early 16th century, this crop and its harvest, curing and use is a technological development. Although Nicotiana was originally brought from Númenor, the Hobbits' history, mentions the first growing of "true pipeweed" during the Third Age, suggesting plant breeding.
• Apiary—Beorn kept beehives... an applied technology. While wild honey may be foraged, and honey products (mead, honey-cakes, etc.) may be produced with such wild honey, I believe The Hobbit this was the earliest mention of beekeeping for the in-universe timeline.

Of course, just because such agricultural technologies are not mentioned does not mean they did not exist earlier, however these developments are not technologically insignificant, and someone must have invented them at some point.

Answer 2

Adding to Lexible's very concise in-universe answer, there are clear themes that Tolkien depicted evil as technology throughout his works. So let's have a look at a few factors that would sit inline with this theory.

Aulë was the Vala whose themes in the music of the Ainur created the physical formation of Arda. Apart from Eru, he is thought to be the father of creation (and certainly by the Dwarves who worship him as a god, since they are his children). Aulë mastered the arts of craft, forging and building, hence why the Dwarves are so attuned to mining and collecting/forging great treasures. Sauron (Mairon) was considered one of his greatest apprentices, and learnt everything from his master before his fall. He was obsessed with order and coordination and disliked waste and confusion, and it was the admiration of Melkor's strength and will that attracted him to become his follower.

It's clear to see that Tolkien was depicting Sauron's character as a metaphor for military regime. After his experiences in the war, and his apparent PTSD, you could understand why he would depict this as evil after the atrocities he witnessed. There's also a clear theme that Sauron's aspirations were initially with good intentions, but because of his blind following of Melkor (the regime), his actions eventually set out to cause disharmony and destruction. Much like a war, where the foot soldiers could be fighting for anything without knowledge. It's not until after the fall of Melkor and the feeling of shame he felt once realising what he had done, that eventually this bred evil thought and darkness.

Tolkien disliked admitting allegory, because in my opinion, he was hiding his thoughts on the real world inside his works, and didn't want people to keep bothering him about it. The clear connections between Saruman/Sauron and forging, building, removing forests and life from areas and generally causing pollution, distress and terrorism in the world is paralleled in our own, the path set out where Sauron had the skills to create terrible war weapons and fortresses shows that technological advancement in Middle-earth is thought of as evil. Where on the other hand, the natural habitats of Lothlórien, Rivendell, and The Shire are depicted as peaceful, good places to live. However, it's also clear that Gondor/Rohan is not included in this, since Tolkien depicted Men to be capable of terrible things if they are corrupted by greed but also capable of good if lead down the right path.

EDIT: So to answer the question directly. Were there any major technological advancements in the Third Age? I'm not sure, but certainly the practical use of these technologies became more apparent. The army of Mordor/Isengard's use of siege weapons is a clear indication of this. Upon the resolution and destruction of Mordor, most of what was "magic" was removed from the earth and the time of men came in the Fourth Age. Since Tolkien believed that he was writing a story within our own timeline and actually Arda is Earth, it would seem reasonable to assume that he was implying we are beyond the Fourth Age now (maybe sixth or seventh actually), and that evil only resides in the free will of men and how they use technology, and no embodiment of evil will exist again until Dagor Dagarath (judgement day).