Who was Alfred Wegener and what did he theorize?
Alfred Lothar Wegener was a German scientist, geologist, and meteorologist. He is most notable for his theory of continental drift (Kontinentalverschiebung), proposed in 1915, which hypothesized that the continents were slowly drifting around the Earth. However, Wegener was unable to demonstrate a mechanism for continental drift, which, combined with his mostly circumstantial evidence, meant that his hypothesis was not accepted until the 1950s, when numerous discoveries provided evidence of continental drift.