This week’s parsha includes one of my favorite psukim:
I like it because I like thinking about the history of technology.
I’m going to talk about bronze and iron, and iron from rocks and bronze from hills.
We mentioned technology in last week’s shiur:
Tziporah’s kitchen knives were sharp rocks. But people had already discovered that there were shiny rocks (or rocks with shiny parts) that you could heat and melt into metals like copper and tin, and that you could mix those metals into alloys that were even harder and stronger, into things like bronze, and you could kill lots of people with it. Technology is always driven by the ability to kill lots of people; that’s how we name “The Ages of Man”: Stone Age, Bronze Age, Iron Age, Nuclear Age.
So everyone wanted to dig into the ground and find those shiny rocks and make bronze. The time period of יציאת מצרים, when the Torah was given, was the late Bronze Age.
But iron is even better than bronze. It can be cast or forged and holds an edge well, and even more important, iron is everywhere. It’s the most abundant heavy element on the planet; in fact, it’s the most abudant heavy element in the solar system.
We need to take a detour into nuclear physics. Iron is the most stable element in terms of nuclear physics
Iron is the most stable element in terms of nuclear physics, so lots of it is made as stars run through their fusion cycle. So iron should be cheap. Why was there a Bronze Age at all? That is because you can mine copper and tin, but you can’t mine iron. Iron nuclei may be very stable, but iron atoms with their electrons are very chemically reactive, and they bind to oxygen, forming rust. Copper and tin oxidize in a thin outer layer that protects the rest of the metal, but iron oxide is porous enough that it will rust through.
So you can’t get an Iron Age until you invent iron smelting technology. That won’t happen until the time of דוד המלך. That’s how I understand the war with the פלשתים:
The פלשתים had military technology that בני ישראל lacked.
So I’m claiming that, at the time the Torah was written, no one could use iron. But I’m clearly wrong; our pasuk mentions it explicitly—ארץ אשר אבניה ברזל! And the Midyanites had iron weapons:
And iron-based weapon technology goes back even further than that:
The answer is, of course, that the problem with iron is that it reacts with oxygen. Just find iron that’s not exposed to oxygen and you can use that. The solar system is full of iron rocks; just get in your Bronze-Age spaceship, grab a small asteroid, and you have enough iron to conquer an empire!
That may not be that easy, but fortunately, sometimes, the asteroids come to Earth by themselves.
The thing about meteoric iron is that it is relatively high in nickel, another stable star-stuff metal that is very common in the solar system. Smelting separates the metals. Archeologists can tell the difference.
So, bottom line: when Moshe tells us that Israel is ארץ אשר אבניה ברזל ומהרריה תחצב נחשת, he means literally that iron comes from the rocks, and copper from the mines.
I think that’s incredibly cool. But I’m wrong.
“Iron is taken out of the earth”! And ספר איוב was written by Moshe himself, so maybe our pasuk shouldn’t be read as sharply as I have.
But I think it still reflects the technological reality. This perek of איוב is a metaphor:
And we need to look at it in context:
It’s a metaphor for strip mining, tearing away the earth to find the treasures hidden within.
So the force of איוב's משל is that even if you could mine iron from the earth and overturn the mountains, you would not find wisdom. That comes from יראת ה׳.
And that is the message of our parsha as well. Moshe isn’t me, isn’t really interested in military technology. The point of ארץ אשר אבניה ברזל ומהרריה תחצב נחשת come at the beginning of the paragraph:
And so, for all the high technology you will develop in ארץ ישראל, you need to remember: