During the middle ages of europe like around 400 to 700 or to 1000
Rich in resources, but they never used them. When the Europeans came to Africa, seeing as the Africans didn't seem to be doing much with the resources, they just took all of it for themselves. And some people too.
It probably could work. Getting a uniform flat surface current could be solved with a good conductor on two opposite edges. However the sheet resistance would be lower than a long wire so you would need more current at a lower voltage. This would require a transformer at additional cost. A long wire can be matched to the supply voltage for direct connection as is currently done.
I would say: Cost - a sheet of uniform thickness nichrome would be more difficult to make and therefore cost more than wire. Physical strength - the sheet would have to be very thin so wouldn't be very strong. Connectivity - you would have to find a way of applying the voltage uniformly to the whole of one edge of the sheet, again complicated to make so expensive. Safety - if the sheet gets damaged you may get higher than expected currents flowing through parts of it. It could melt and break, causing an arc.
Relatively speaking yes. But that is because Europe was so poor in this period. Africa's problem is geographic and weather systems, combined with not having a high yield foodstuff. Great Zimbabwe is a good example, a large powerful State that grew up and disappeared, hit by Famine (Weather system), and also suffered from not having any other large opponent close at hand, so there was no interchange of ideas and technology. The Geography was particularly difficult, the River systems (except the Nile) didn't lend themselves to interchange of cultures. Western (World) Civilisation started in the Euphrates and Tigris Rivers because at the time the weather was more clement, but the 2 rivers meant that there were different ideas exchanged between different tribes. Wheat and barley also had a large influence. It is worth noting that Japan Population 120 million is supported by about 60% of its land, (the rest is too mountainous) on Rices which has 2 harvests a year and a higher Calorie per acre than Wheat. England has a Population of 52 Million and has a larger land area for cultivation, but Wheat only has 1 harvest a year and less calories per acre. Africa below the Sahara didn't have these crops, they didn't have the inland sea like the Med, or Sea of Japan, and where there was great Civilisations grew up they were alone at the time, so no interchange of ideas. It is rich but it is harnessing that richness that is a problem.
