While we do not usually consider physical “hardware” (rocks, weapons, machines, etc.) to be knowledge stores, their functional use is defined by exactly that. An example: this picture of an Acheulian hand axe shows some of the knowledge that went into making it and is “stored” in it.
Material: It is a chert—a fine-grained sedimentary rock that, since it has no grain or cleavage plates, can be chipped into shape when hit properly. It is strong enough and can hold the sharp edge needed for the tool.
Size: In addition to being selected for material characteristics, it was likely around the right size when it was first picked up.
Flaking: This is a bone-cutting axe used with a downward striking action. The lower right-hand side of the picture shows the primary cutting edge. This edge must have just the right angle at the point the axe hits the bone. With too shallow an angle the edge will be blunt and it won’t cut; too sharp an angle and it will be thin and will break. This range of effective angles is quite narrow and required considerable knowledge and skill on the part of the tool maker to produce consistently.
Strength: As well as selecting the rock for its strength and flaking characteristics, this particular axe has a “reinforcing ridge” running most of its length. This provides strength to the tool, while allowing the cutting edge to be sharper than it might otherwise be.
Other characteristics: This tool has a good palm-shaped top where it would be held. It not only conforms to the size of a hand, it has chipped indentations where the user’s thumb and fingers would be positioned.
According to its provenance, this axe is about 750,000 years old.
This Clovis Point shows the advance of the knowledge stored in hardware. It is much more refined than the hand axe:
Material: This is flint. It is harder and more brittle than the chert (though Clovis points were also made from cherts). This allowed finer and sharper edges and points—much more suitable for the arrow and spear heads for which Clovis points were produced.
Smoother: The flaking is much smaller (and much harder to do). The flaking is “fluted” across the edges. This allowed the concave part of each flute to be sharper while the raised part provided strength; this is similar to modern serrated-edge kitchen knives. Notice the similarity in concept to the reinforcing ridge on the Acheulian axe.
Assembly: This is probably the key difference. Most Clovis points were intended for use in an assembly. That is, the points were only part of the final product. They usually had a notch or similar indentation at one end to allow them to be tied to a stick for use as a spear or arrow. The tool maker would have to envisage the final tool for assembly before making this artifact. This requires foresight. Producing an assembled tool requires a much higher level of sophisticated planning and knowledge than does the production of the hand axe.
This Clovis point is around 13,000 years old.
Assuming the dates are accurate, it took around 737,000 years for the knowledge of making stone tools to progress from the Acheulian hand axe to the Clovis point.
Why did it take so long for the knowledge stored in hardware to progress from hand axe to arrowhead? The answer lies largely in the brain-to-brain knowledge transmission mechanism. When knowledge is stored only in the brain, it can only be passed on through speech and/or real-time observation.
Instructing someone and showing someone is a direct brain-to-brain transfer of knowledge. If the brain holding the knowledge cannot pass it on to a brain that can absorb and retain the knowledge, that knowledge is lost. Knowledge resident in one geographical area can only be transmitted to another area if the person holding the knowledge relocates. Equally, knowledge acquired in one generation can only be retained if it is passed on person-to-person to the next generation. Given the characteristics of knowledge-in-brains (see later), there is a good likelihood that the knowledge will be lost or corrupted as it moves through space, between people, and through time.
To better facilitate this retention and transfer of knowledge, the human race needed to develop another knowledge storage medium.