 The mediocrity principle was implicitly applied during the 17th century, when astronomers attempted to measure the distance between distant stars and the Earth.By assuming that the Sun was just an average star, and that some stars seemed brighter simply because they were closer to us, they were able to estimate how far these stars were from the Earth.Although this method was flawed in view of the differences among stars, it gave astronomers at that time a rough idea of how far the stars were from the Earth.