A question about advancements of weaponry

[Inziladun]

A short answer seems to me to be that the use of substances such as gunpowder and explosives have, in Tolkien's Arda, a connotation with evil.

When the reader is first told of goblins in Bilbo's tale:

It is not unlikely that [goblins] invented some of the machines that have since troubled the world, especially the ingenious devices for killing large numbers of people at once, for wheels and explosions always delighted them.

The Hobbit Over Hill and Under Hill

And in LOTR Aragorn has a singular word for Saruman's use of explosives:

'Devilry of Saruman!' cried Aragorn. 'They have crept in the culvert again, while we talked, and they have lit the fire of Orthanc beneath our feet.'

The Two Towers Helm's Deep

"Devilry' I would equate with Morgoth or Sauron in that context.

Basically, it appears that even the research of such warfare methods is frowned upon by the "good" in Middle-earth, and those who delve into those matters are either evil or heading that way.

[Rhod the Red]

Middle-earth is pre-Middle Ages for us, and "in its own time".

So it's both back in the past and its own timeline as it were.

[Galadriel55]

I completely agree with what has been said above. I also want to note that not only does ME technology seem to not develop overtime (in a positive way, not Sauron's/Saruman's things), but it also follows a general waning pattern. Start out with FA "magical" Elven swords, then lose that technique. Then you have a few bumps and spikes in the graph as you reach the height of Numenor, Arnor, Gondor, Dwarvish skills... but overall the trend goes downwards. The weapons (and artifacts in general) that are older are better and more valuable.

[Inziladun]

Having given this more thought, I wonder if it wasn't Saruman's apparent non-magical "fire of Orthanc" that may have lit the fuse (pun definitely intended) for the ultimate development of such weapons, leading to their widespread use beyond the Fourth Age.

With the Istari gone, Elves dwindling and having over time less and less contact with the kingdoms of Men, it doesn't seem much of a stretch that over time the moral equation of impersonal technology designed to kill great numbers with "Morgothian" behavior would have fallen by the wayside. With that blockage gone, and always new enemies (of other Men), the motivation would have been there.
Though at the end of LOTR the reader is left with hope that King Elessar would lay a sure enough foundation that Gondor at least would remain true in heart to its old allegiance to the West, Tolkien himself began a story set after Elessar's death in which Gondorian boys were playing at "orcs" and the people there, in keeping with the state in our own world, were becoming ill at ease with peace. All that is to say that if the reader had been given a glimpse into Middle-earth just a few hundred years later, I don't think it's impossible that cannonballs could have been flying in some battle or other.

[urbanhiker]

My opinion, and it is only an opinion, is that there are no rifles, artillery and other modern weapons of war in the Lord of the Rings because those things have little or less or no romantic or dramatic value. No one ever quested for a shotgun. No one ever reforged a broken mystical cannon that was the heirloom of ancestors. No one ever etched magic runes for the downfall of one's sworn enemies into a howitzer, at least not that I'm aware of.

[Morthoron]

For Tolkien and other Englishmen of his generation, the romanticism of war died on the fields of Flanders, on the Somme and at Verdun. There is little glory in a rat-infested trench, and no honor in picking off the enemy hundreds of yards away.

That being said, if you page through The Hobbit to the section where Tolkien describes Orcs, he says basically that they were the future inventors of weapons of mass-destruction. Also, when Gandalf strikes several Orcs dead in the goblin cave, Tolkien describes the smell of gunpowder. I would quote the passages, but the football game is starting, and I do have my priorities.

[Rumil]

Another aspect (in story if you like) is that the elves appear to have gone directly to the iron age without having to do all that inconvenient mucking about with a bronze age. IIRC the Valar passed on some tips.

Bronze swords are basically a pain, lack of tensile strength etc, they were made in our history, but were no match for basic iron swords, let alone well-forged steel. Humans have been using other weapons eg spears for far longer, simple pointy-stick ones for as much as 500,000 years allegedly and stone-tipped for at least 200,000. Whether for hunting or warfare is an open question.

So in a way the inhabitants of Middle Earth are ahead of the curve instead of behind it.

As said there's much evidence of gunpowder (whether Gandalf's fireworks and flash-bang in the goblin cave or the fires of Orthanc). Also incendiary weapons, something like Greek fire - probably naptha-based - Sauron's projectiles at the siege of Minas Tirith that kindled by some nameless art and Saruman's flame projector that burnt up an ent. Debateable how much of each is 'magic' or pyrotechnics, but to be fair most medieval observers found it tricky to distinguish between the two.

The alchemists and early gunners and 'fireworkers' were often viewed supiciously as being in league with evil forces, the whiff of sulphur probably not helping their case!