We used to know how to get together and really let our hair down. Then, in the early 1600s, a mass epidemic of depression broke out - and we've been living with it ever since. Something went wrong, but what? Barbara Ehrenreich unpicks the causes of our unhappiness
This process was voted from nature most important invention of the 20th century. It makes fertilisers that doubled the earth population. Explained in the GWAL 2007 invited speak on Godel.