Wikipedia:Reference desk/Archives/Science/2018 October 2

= October 2 =

Why did it take so long to invent the heavy plough?
The heavy plough is hailed as one of the most revolutionary technological advances in the history of agriculture. But, from what I've read, the heavy plough is, quite literally, just a heavier version of the regular plough. Why did it take so long to invent, then? — Preceding unsigned comment added by 90.69.6.163 (talk) 10:05, 2 October 2018 (UTC)
 * The Plough invention described was replacement of the simple ard by the carruca turnplough around the 7th century, though a heavy iron moldboard plow was already developed in China's Han Empire in the 1st and 2nd century. The carruca may have been introduced to the British Isles by the Viking invasions of England in the late 9th century. The article Iron Age gives estimated dates for the spread of iron tool- and weapon-making around the World but cannot explain "Why not earlier?". DroneB (talk) 13:09, 2 October 2018 (UTC)


 * See https://www.deere.com/en/our-company/history/john-deere-plow/. The main rise of technology came with the rise of industrialization and mass transport. Maybe someone already invented it in the roman empire but no one cared because it was slave work anyway and much cheaper to buy additional slaves to do double the work. --Kharon (talk) 15:01, 2 October 2018 (UTC)
 * What relevance does John Deere (who were one of the inventors of the steel plough) have, a thousand years after the invention discussed here? Andy Dingley (talk) 22:38, 2 October 2018 (UTC)
 * "The scratch plow which preceded the wheeled plough had been ideal for the light sandy soils of Southern Europe" which means that the heavy plow was probably not necessary in Italy. Ruslik_ Zero 12:28, 3 October 2018 (UTC)


 * It isn't merely heavier. It's also wheeled and (most importantly) uses a more robustly constructed share and mouldboard, capable of turning a furrow, not merely acting as a harrow. Which also requires a greater investment of iron, still a highly valuable material in this period. Additionally it also requires a team of draft oxen to pull it (oxen rather than horses at that time). You can't pull it with a donkey, or a couple of friends. Andy Dingley (talk) 22:38, 2 October 2018 (UTC)

Can anyone identify this caterpillar (Vietnam)
Hi

I was wondering if anyone could identify this caterpillar? A colleague/friend is on a work trip to Vietnam and took this photo.

Hermitical (talk) 23:10, 2 October 2018 (UTC)


 * I spent quite a lot of time looking at images of caterpillars in Vietnam and found several that looked like your image, but on all occasions the photographer simply said "wow, look at the hairy caterpillar, I wonder what it is?", even one guy who had happily identified all the birds that he saw. So, unfortunately there's nothing to go on. Mikenorton (talk) 17:54, 5 October 2018 (UTC)