Aztec chinampas seven crops yearly yields

For much of the nineteenth century, French-speaking Wallonia was Belgium's industrial powerhouse, rich in coal mines and steelworks. As heavy industry declined, economic growth increasingly shifted toward Dutch-speaking Flanders. The reversal changed the balance of wealth between the regions and added an economic dimension to Belgium's linguistic and political tensions.

In most mammals, the risk of death rises sharply with age. Studies of captive naked mole-rats found no clear increase in mortality risk across the ages observed, even though some individuals lived for decades. That does not mean they are immortal or never age, but their unusual survival pattern challenges expectations based on other mammals.