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>So is iron or bronze "more advanced technology"?

Iron. Advancement doesn't mean "overall quality," it means difficulty and sophistication, including the sophistication and difficulty of the necessary supply chain. A computer is a more advanced technology than a shovel, even though if you need to dig a hole the computer would be useless. That's the definition of advanced.

Bronze is not easy to make, but iron is more difficult, requiring better furnaces. Given access to the right raw materials, any civilization that can make iron can make bronze but not the other way around.

>Find the appropriate ore. Stick it in a fire.

Open fires aren't hot enough to melt any but the softest metals, like tin. Building fires required to reach metallurgical temperatures is a very difficult task whose know-how evolved slowly over millennia.

> Given access to the right raw materials, any civilization that can make iron can make bronze but not the other way around.

However, in a sense the spread of bronzemaking required a more advanced society and intercultural trade because rich deposits of copper and tin ore can be located thousands of kilometers from each other. Most of the tin used by the Mediterraneans was imported from Britain.

> Open fires aren't hot enough to melt any but the softest metals, like tin.

Extracting metal from an ore (smelting) does not in general involve melting temperatures, and neither does working the metal into tools.

I was about to say this. Iron smelting was a later invention, but once it was discovered, it's actually significantly easier to smelt iron than bronze, even if you start from zero (i.e. knowledge only, no tools), due to the geographical scarcity of tin. For instance: https://www.youtube.com/watch?v=DyGLE0usN_I

So you can easily say bronze requires a more advanced civilization than does iron, given the more complicated trade routes required. In that sense, developing Bronze before smelted iron is partially a historical/geological artifact (although one replicated in the Americas). the southern half of Africa was cut off from European and Asian sources of tin but geographical barriers (and there are no tin sources in Africa itself), so they skipped Bronze and went straight to Iron smelting.

>Most of the tin used by the Mediterraneans was imported from Britain.

This is an interesting one because it touches on the evolution of bronze. Early bronze was made from nearby co-occurring deposits, including arsenic bronze which was made from the arsenic that is often found along with copper. However because tin was much rarer than copper, and because there was a lot of it in Britain, the long-term evolved solution was to transport the tin across great distances. I'm not completely sure but I believe that the tin trade route post-dates the invention of bronze.

>Extracting metal from an ore (smelting) does not in general involve melting temperatures, and neither does working the metal into tools.

That's a good catch, but it's also worth pointing out that campfires still can't smelt copper, and also that early iron furnaces, incapable of melting iron as they were, still had to be enclosed and fed with forced air.

Getting access to tin is hard. And making wrought iron isn't really harder to do than making cast bronze. The issue is that if you don't know how to turn it into steel (which isn't hard, just requires discovery), wrought iron is highly inferior to bronze.

India actually basically skipped a bronze age, going largely from unalloyed copper straight to steel rather early, without any intervening period where bronze was widespread. So the bronze first then iron developmental pattern is not universal.

The earliest refining of iron also produced a little steel as a byproduct. There is reason to believe that iron refining is as old as, or even older than bronze, and steel would have been made with that iron. However bronze was easier to work with (I think this refers to readily available ore though I haven't looked into this and could be wrong as to reasons). In general a craftsman would use bronze where possible, iron where bronze didn't work (which wasn't often, bronze is better than most people think), and steel only where required. For files and other metal working tools not much steel is required and the advantages would be worth it (though these might be case hardened iron - we suspect they knew how to do this long ago but there is no historic record to be sure)

The are plenty of stories passed down about magic swords that could cut others in half. If someone collected enough steel from the little that would made it would be magic compared to other swords, but the effort to collect that much steel would be enough that few such swords would be made.

>wrought iron is highly inferior to bronze.

What?

Wrought iron is immensely more useful than bronze in many applications demanding strength (per weight or per volume, take your pick) and/or toughness.

There's a reason things like metal bridges, railways, etc. all became common only after wrought iron became readily available.

Likewise for cast iron, other than malleability it is mechanically superior to bronze.

There's a reason the only time you see bronze these days is bushing material and applications demanding corrosion resistance for which aluminum/zinc alloys would be unsuitable.

To clarify, I meant superior for contemporary needs. People weren’t building large scale structures out of metal, but they were crafting tools, weaponry, and armor, for which wrought iron’s softness is a dealbreaker.

Dwarf Fortress taught me to always import bismuthinite and cassiterite stones on embark, along with willow logs.

Real history shows that tin mines were a major strategic asset for pre-steel civilization, and Devon and Cornwall on Britain had the oldest and deepest mines in the world, and continued working after other European sources were exhausted.

Even if you know how to make steel, making types suitable for non-specialty work in significant quantities was difficult until smelting technology upgraded to the Bessemer process, and the types of available steels meant that a lot of cannons were still cast bronze. On a historical scale, it is only very recently that newer steel alloys and mass-produced aluminum has obsoleted bronze for just about everything but cymbals, certain corrosion-resistant fittings, and yellowish coinage cladding.

I thought it was mostly a reference to what was used in the weapons of the era. Bronze has several advantages over iron for a variety of uses, but a bronze sword or bronze tipped spear is at a severe disadvantage against an iron equipped foe.

> It's also easy to underestimate the difficulty in mundane technologies. Take bread for instance; this is how you make bread: Grow a grass (cereal crop). Separate the seeds, dry them, and then shell them to get your grains. Now grind it into flour, and then mix it with water, fat, and salt. Let it sit out to grow a yeast infection. Stick it in a fire, and then you get bread. Compare this to typical metalworking: Find the appropriate ore. Stick it in a fire. Depending on the metal, let it melt completely and pour it into a sand cast, or get it red-hot and then bang on it with a hammer.

Your example doesn't support your point. You're simply going into more detail on the baking process than the smithing process. In particular, none of these things are trivial:

* finding the right ore (generally depends on trade and specialization)

* making a fire hot enough to melt metal

* making a sand cast

* alloying the metal

* rooting out impurities such that the finished artifact is useful

* the technical processes of casting and forging

"Compare this to typical metalworking: Find the appropriate ore. Stick it in a fire. Depending on the metal, let it melt completely and pour it into a sand cast, or get it red-hot and then bang on it with a hammer."

This reminds me of something I read about the "Great Leap Forward" in China, where my impression is authorities thought something like, yeah, metalworking is simple, let's get everyone making steel, and then the results were not good for much.

So, sure, bread is something that doubtless took thousands if not tens or hundreds of thousands of years to develop, but that's no reason to take metalworking for granted.

I keep being reminded of this post which I first saw on HN: http://johnsalvatier.org/blog/2017/reality-has-a-surprising-...

Except, come on, it's not surprising.

No, deriving metal from ore is not as easy as you make it out to be. Even the construction of a simple bloom furnace requires a fair amount of knowledge of the properties of fire. You can make a bloom furnace with your hands out of mud, so if it was trivial to make metal objects, why was the stone hand ax the predominant tool on record for most of human history?