Scientific and technological revolutions are happening every day as we get better and better at asking questions and figuring out answers. On this Theme Thursday we think back to some 
pretty revolutionary discoveries in the earth sciences
Four Revolutions in the Earth Sciences: From Heresy to Truth – During the twentieth century, scientists made four fundamental and surprising discoveries about the Earth: our planet is billions of years old, continents and ocean floors move, rocks as big as mountains fall from the sky, and humans are changing the climate. When first proposed, each violated long-held beliefs and quickly came to be regarded as scientific, and sometimes religious, heresy. Then, after decades of rejection, scientists reversed themselves and came to accept each theory. Today, scientists regard deep time, continental drift, meteorite impact, and anthropogenic global warming as established truths.