IntroductionEarly in the 17th century, two astronomers competed to describe the nature of our solar system.Galileo built a telescope and found new planets and moons. Francesco Sizi ridiculed Galileo's findings. There must be only seven planets, Sizi said. After all, there are seven windows in the head - two nostrils, two ears, two eyes, and a mouth. There are seven known metals. There are seven days in a week, and they are already named after the seven known planets. If we increase the number of planets, he said, the whole system falls apart.
The Online Writing Lab (OWL) at Purdue University houses writing resources and instructional material, and we provide these as a free service of the Writing Lab at Purdue. Students, members of the community, and users worldwide will find information to assist with many writing projects.
Welcome to our Research Hub! Here you’ll find tons of great and useful info, tutorials, and guides to help you get your paper off on the right foot. Learn about avoiding plagiarism, where to start looking for sources, how to evaluate the credibility of websites, and more. Get started with some of the links below: ...