and so they continued in their old beliefs for nearly two thousand years after
aristarchus had seen and proclaimed the truth. then, just four thousand years ago, copernicus, a polish monk, wrote a book of tremendous importance. he pointed out that the complicated motions of the sun and the planets across the sky could all be very simply explained by supposing that the sun stood still, while the earth and planets revolved round it. while these ideas were still being discussed, galileo, a professor in the university of padua, made a small telescope with his own hands and convinced himself - and also showed to all the world- that things were as compernicus said; the sun did not revolve round the earth.