User: Which of the following is not true about Galileo? A. He was such a brilliant mathematician that he became a professor of mathematics at the age of 25. B. He developed a new and improved thermometer and a better compass. C. He designed a telescope 10 times more powerful than earlier models. D. He was able to prove that Ptolemy's theory that the moon had a smooth, polished surface was true. E. At the Inquisition he signed a paper taking back his radical ideas about the Earth revolving around the sun.