Scientists and archaeologists have analysed slagheaps left by the copper mines in Edom, an area encompassing parts of what is now southern Jordan and Israel. They found signs that mines in different parts of the region made the same advances in smelting techniques at the same time in the 11th century BC, just before the age of the biblical Kings Saul, David and Solomon.
You know, knowledge being a non-rivalrous and often enough non-excludable good.
Sure, being part of the same political organisation will aid in the spread of such knowledge. So, for example, the turn of the 19th/20th century saw advances in gold extraction from ore. Likely this did spread through the Empire, from S Africa to Oz perhaps, faster than it did to Siberia or the US.
But not entirely convinced that you’d be able to measure that speed from slag heaps……