What was the most important invention ever, and when was it made?

How did german physicist werner heisenberg's uncertainty principle shake beliefs in newtonian physics?

Characteristics of what type of economic system are being described below? 1.economy in which some/all of the basic economic questions answered by central authority 2.trade generally limited to what is produced through the influence of the government a. command economies. b. market economies. c. traditional economies.

What are some effects outside of europe because of world war 1?