Sentence:  You would think the practitioners of the dismal science of economics would look at their demand curves and the data on incomes and taxes and pronounce a verdict, the way Galileo and Copernicus did when they showed that geocentrism was a fantasy because the Earth revolves around the sun (known as <WSD>heliocentrism</WSD>). 
Meaning of the word marked with <WSD> tags:  The phenomenon of the Earth revolving around the Sun.