This article illustrates the importance of astronomical instruments by suggesting that Copernicus was not “proved right” until the development by Tycho Brahe of sophisticated observational tools late in the 16th century. I think this is a misleading example. Tycho’s records did allow his one-time assistant Johannes Kepler to move closer to “proving” Copernicus right, early in the 17th century. But Tycho himself aggressively championed a hybrid system that retained Earth at the center of the universe.

Adam Serchuk
Madison, Wis.