Which brings me to today's question: when was the scythe invented and why did it take so long for it to replace the sickle?
Wikipedia has this about the history of the scythe:
The scythe may have dated back as far as c. 5000 BC, and seems to have been used since Cucuteni–Trypillia settlements, becoming widespread with agricultural developments. Initially used mostly for mowing hay, it had replaced the sickle for reaping crops by the 16th century, as the scythe was better ergonomically and consequently more efficient.
That's quite a leap, from the middle Neolithic to the 16th century, with no data in between.
Britannica has this:
The exact origin of the scythe is unknown, but it was little used in the ancient world. It came into wide use only with agricultural developments of the Carolingian era (8th century AD) in Europe, when the harvesting and storing of hay became important to support livestock through winters.
The question of whether people had scythes in Roman times is much debated, but anyway there are about 10,000 Roman sickles in European museums and not one object that everyone agrees is a Roman scythe. So if they did have them, they didn't use them very much.
So here is a puzzle. A scythe, which is not a very complex tool, is vastly superior to a sickle for cutting grass. Wheat and barley are grasses, and the scythe works better for them, too. So why is there next to no evidence for the use of scythes before 500 AD?
I have no idea, and so far as I can tell, nobody else knows, either.