The World in 1200 and the World Now

In 1200, a merchant in Baghdad might trade with someone in Samarkand or Guangzhou, but the Silk Roads, the Indian Ocean trade routes, and the trans-Saharan routes were mostly separate circuits. Goods, people, and ideas moved long distances, but slowly, along fixed overland and coastal paths, and a disruption in one network, like a war along the Silk Roads, did not necessarily touch the others. Population grew slowly, most people lived in the countryside, and life expectancy stayed low almost everywhere because disease, famine, and limited medicine kept death rates high.

Today those separate networks have merged into one system. A shipping container loaded in Shanghai can reach Rotterdam in weeks, a financial crisis in one country can spread worldwide in days, and a virus can cross continents by plane in hours instead of years by caravan. Population has exploded past 8 billion, most people now live in cities, and life expectancy has roughly doubled almost everywhere since 1900, driven by vaccines, sanitation, and industrial food production. The difference is not just speed. It is density of connection: nearly every region now touches every other region directly, instead of connecting only through a few middlemen nodes.

This topic ties the whole course together by asking what stayed the same underneath the change. Sugar moved from Mediterranean plantations before 1450, to Caribbean slave plantations after 1500, to a globally traded commodity shipped in bulk today. Cotton and oil follow similar arcs: a good gets produced somewhere, moved somewhere else, and reshapes labor, empire, and environment along the way. The Silk Roads, the Columbian Exchange, and the container ship all solved the same problem, connecting distant places, with the technology each era had.