The Nature article is not about 2000 BC but 2000 BP, i.e. before present, with the oldest site around 2300 before present, i.e. around 300 BC.
So these are old sites of iron production, but not as old as the first production of iron in the Anatolia-Caucasus region, from where it spread in Europe, West Asia and North Africa.
In Egypt, some ancient objects made of meteoritic iron have been found, which precede by a few millennia the discovery of how to extract iron from minerals.
Another of your links points to a book "Metals in Past Societies" which is supposed to contain information about sites really older than 2000 BCE, but I am skeptical about the dating until I read the book, because the book is less recent than the 2024 article from Nature, which ignores those sites that are claimed to be older.
I have been able to access the book "Metals in Past Societies" that was claimed as source for 2000 BC or earlier iron metallurgy.
As I expected, the book is far more nuanced than the optimistic claims from the link provided above.
The apparently very old datings of iron metallurgy are datings of charcoals.
The book explains that charcoal datings provide very little information about the true age of the iron working environment where they were encountered, because the age is not the age when charcoals were made and used by the iron smiths, but the age when the tree had grown.
In the area where the charcoals were found, there are trees that live for hundreds of years or even for millennia, and there are also dry places where wood can be preserved for hundreds of years after a tree had died. Dead wood would have been preferable for making charcoal, because it is already dried.
So if a charcoal is dated to 2000 BC, that only provides an upper limit for the age, but the iron smiths who used the charcoal might have lived even one or two millennia later.
I suppose that improved dating is the reason why the more recent article for Nature only mentions 300 BC as the age of Nigerian iron working sites, instead of citing the older claims about a greater age.
That said, the evidence makes likely that iron metallurgy in Sub-Saharan Africa developed mostly independently, though its beginning might have been caused by information that had reached that area from the North.
In TFA it is stated that before bronze (i.e. copper-tin alloy) copper was used for tools.
This is not true, because pure copper has always been too soft to be used in any tool. Pure copper was used for some purposes, but never for tools that had to be strong and hard, e.g. for knives.
Before bronze, for several millennia tools were made from alloys of copper and arsenic or antimony (3 metals, lead, copper and gold have been known for many millennia before other metals became known, like tin, silver and meteoritic iron). Neither of arsenic and antimony was known in pure form, so unlike the bronze made by mixing metallic copper with metallic tin, the copper-arsenic or copper-antimony alloys were made by mixing the sulfide minerals of copper and arsenic or antimony (which are all found together where sulfide minerals are mined), before smelting the metallic copper alloy from the minerals (which for sulfide minerals is done by first roasting the sulfides into oxides, to drive the sulfur away, then reducing the oxides with charcoal).
The article doesn't mean copper alloy tools though, it means copper tools, including weapons. At least that's how I read this:
"Copper was accessible enough and easy enough to work that it allowed early proto-states to reliably arm their warriors with something better than stone weaponry, which often chips or breaks under impact. Copper is a soft metal, hence its use in pipes and wiring today. But it generally won’t break, and though it does bend easily it can also be bent back into shape."
why do you think the article doesn't mean copper alloy?
The only use of the word 'pure' is right before iron.
it's pretty common to refer to Otzi's axe as a 'copper axe', right in the wiki page: "Ötzi's copper axe was of particular interest.". but it's 99.7% copper. It contains other materials
I really dont understand jumping from 'copper tools' to 'pure copper tools'. Otzi's axe was maybe both an example of his mastery of the profession and a useful tool (it shows signs of use and rework).
Because it said the copper tools can bend easily and be bent back into shape. The copper alloy wouldn't be so soft. And Otzi's axe wasn't an alloy, ie an intentional mix of materials, it's just that copper naturally occurs with slight impurities.
It is pretty certain that not every country exercises this power, though it seems that a few other English-speaking countries also do this.
During the last quarter of century, in many hundreds of border controls through many countries of Europe and Asia, including in places with tight security like Israel, I have never seen any case of searching for information in any belongings of the travelers, like computers or smartphones or even notebooks or the like.
Israel is a country that long before 9/11 had extremely effective methods for testing travelers at border control, and unlike the Americans they kept their methods unchanged after 9/11. Unlike USA, they have never relied on technical means, like X-ray scanners or SSD/HDD searching, but they have relied on trained humans who interviewed the travelers and assessed whether they lie about their purpose or not.
« unlike the Americans they kept their methods unchanged after 9/11 »
That's a good one :) It shows a couple things, like:
• a certain independence from Uncle Sam (like they displayed when they bombed the USS Liberty in 1967)
• that their own population was already sufficiently propagandized into paranoia mode (fear and loathing of “evil muslims”) in order to never make peace and keep the hate up
• and of course that they knew there was nothing to worry about wrt the 9/11 hoax
CXMT has entered the market, but for now they cannot increase their production fast enough to influence significantly the global prices, due to the US "sanctions", which prevent them to buy modern fabrication equipment.
So they must use older equipment, which has low productivity for state-of-the-art memories. Because of the "sanctions" there are now Chinese companies that have progressed significantly in semiconductor manufacturing equipment, but the effect of this will also take some more time to manifest.
Nonetheless, if the 3 big memory producers will not be able to increase the availability of memory until 2028, then until then CXMT will grab with certainty a major part of the market (they have already grown quickly until 10% of the market, from a negligible percent previously).
The rest of the world won’t care. They will use whatever memory they can get, and if the Chinese are willing to supply it over the next 5 to 10 years, they end up on top…
For now, there are only 3 that matter, but the reason is purely because the US government has sabotaged their competition as soon as it became apparent that the incumbents would lose market share.
Without what the US government did and still does, the prices of memory would have never increased so much and all the world would not have been forced to pay so much for memory.
« Without what the US government did and still does, the prices of memory would have never increased so much and all the world would not have been forced to pay so much »
If that is true (and given the reasons you provide below, and the general quality of your commenting, I assume it is) then the situation is similar (if less militarized) to that of the oil sector, where the cost increase is likely higher by perhaps three orders of magnitude.
I assume that some Americans have downvoted what I have written, but this is a fact that is true beyond any reasonable doubt.
A few years ago, the US government has added the Chinese vendors of DRAM and of flash memory on their sanctioned entity list exactly at the time when Apple and other major computer manufacturers were evaluating the replacement of products from Micron and the like with the Chinese alternatives. This was prevented by the "sanctions".
There is absolutely no doubt that the so-called sanctions did not have any other purpose than removing the competition for Micron.
The official reason is absolutely ridiculous, i.e. that they are among the companies that provide products to the Chinese military.
If that would have been the reason, then 100% of all existing Chinese companies from any domain of activity would have to be put on the "sanctioned entity" list, because any of them would sell to the military of their country, if given an opportunity, like all companies from USA will provide products and services to the US military, given the opportunity.
While the Chinese memory makers will obviously also sell to the military, almost all their production goes into consumer products, like smartphones and laptops, which are the main products affected by the US "sanctions" (which are no true sanctions, because true sanctions against China would have been accompanied and conditioned by some political requests, which is not the case for any of the US "sanctions").
There is also no doubt that without the US "sanctions" the Chinese memory makers would have bought the latest semiconductor manufacturing equipment and they would have had the production capacity to flood the market with their products when Micron, Samsung and Hynix stopped providing enough memory for anyone who is not among their top 5 customers.
Thus their is no doubt that the US government has stolen a lot of money from my own pocket when I was forced to update a couple of old computers this year, by artificially restricting the amount of memory that is produced and preventing competition in this market.
As I see it, any US citizen who supports the actions of their government to restrict the production around the world of various kinds of goods and to prevent competition in various global markets, actions that have increased the prices of many kinds of consumer products in all countries, is an accomplice to theft from a very large number of people all over the world, who are forced to pay inflated prices for such products, resulting in money that goes from many countries into the pockets of the shareholders of a few big transnational companies, including Qualcomm, Micron, Samsung and Hynix.
> I assume that some Americans have downvoted what I have written, but this is a fact that is true beyond any reasonable doubt.
I would guess that the reason for any downvotes is that even if what you wrote is completely true it isn't really relevant, because the current problem is not lack of competition. The current problem is a huge increase in demand over a short time.
Even if there were no restrictions on China and they had latest generation fabs, they would not have had latest generation fabs just sitting around idle. They would be unable to meet the current increased demand for exactly the same reason everybody else can't.
Like anything else, recursive make can be used in a right way and in a wrong way.
It can be used in a wrong way, like described in the article linked by you, when it results in slow project building.
How I use recursive make, it does not introduce any slowdown whatsoever.
I organize my projects so that there is a one-to-one correspondence between leaf Makefiles and the final files that are generated as a result of the building process, regardless of the file types, e.g. executable files, static libraries, dynamic libraries, executable files including GUI resources, documentation files etc.
A generated file may depend on source files located in many directories. Those files are searched and used by the single "make" command that generates one result file (by using the GNU make directory search functions, e.g. "wildcard", "notdir", "addsuffix", "addprefix"), not by recursive make invocations.
I also never write dependencies manually, I always generate them automatically. I also never write the names of source files in makefiles, I only provide a top directory and/or a list of subdirectories, where source files can be found automatically. This means that I never need to edit a makefile when source files are added, moved, renamed or deleted.
I use recursive "make" invocations only for generating multiple result files with a single make command in the top of a directory tree that contains subdirectories where each result file will be built (which also store the corresponding intermediate files, e.g. object files).
The directory tree used for project building is located elsewhere than the source files and its tree structure is not related to the tree structure of the source files, but it is determined only by the number of final files that are produced when building the project, which will be included in a release.
The analysis from TFA and also the study that it comments on are much better than what is typical for nutrition studies.
TLDR:
1. If fatty liver or diabetes/prediabetes is the problem, a low-carb diet, e.g. a keto diet, was the most efficient.
2. For problems like fat in other organs, e.g. muscles, causing reduced insulin sensitivity, only weight loss mattered, regardless of the diet that caused it.
3. For cardiovascular problems, e.g. atherosclerosis or high blood pressure, a balanced diet, e.g. Mediterranean, was superior to both low-carb and low-fat diets.
Something not discussed in the article is that unlike the alternatives, a low-carb diet/keto diet is much more expensive. In any diet that provides a desired amount of protein and fat, carbs are basically free. When the majority of the calories are no longer provided by carbs, the diet may be unaffordable for many people all over the world, so for them a keto diet may be acceptable only for a short term, as a treatment against prediabetes or fatty liver, but not as a permanent diet.
Before OOP became popular, there already was an alternative for hiding internals in order to prevent incorrect usage: what many languages call "modules" and Ada calls "packages".
For many applications, modules are much more flexible and convenient for hiding internals than class hierarchies that may force an irrelevant structure on the internals and which may make difficult to selectively choose what is visible and what is hidden.
That article argued correctly that the World's greatest oil power is the one that has the greatest control upon oil price.
For now, that is China due to both high consumption and huge facilities for oil storage. They maintained a relatively low oil price until now, but they could rise the price of oil at any time.
So these are old sites of iron production, but not as old as the first production of iron in the Anatolia-Caucasus region, from where it spread in Europe, West Asia and North Africa.
In Egypt, some ancient objects made of meteoritic iron have been found, which precede by a few millennia the discovery of how to extract iron from minerals.
Another of your links points to a book "Metals in Past Societies" which is supposed to contain information about sites really older than 2000 BCE, but I am skeptical about the dating until I read the book, because the book is less recent than the 2024 article from Nature, which ignores those sites that are claimed to be older.
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