During the Scientific Revolution of the 16th and 17 century, empiricism and modern science replaced older methods of studying nature – European research methods that mainly involved reading texts by ancient writers. In ancient times, natural philosophers made observations of nature and came up with explanations, but never conducted experiments to test those explanations, because creating an artificial situation was considered an invalid way to discover the rules of nature. The scientific method of testing hypotheses was first recorded in the 10th century by Ibn al-Haytham (Alhazen), inspiring Roger Bacon to begin experimenting in 13th century Europe. By the time of the Revolution, these methods resulted in accumulation of knowledge that overturned ideas inherited from Ancient Greece (primarily Aristotelian physics, which includes the modern domains of physics, chemistry, biology) through the Middle Ages and Islamic scholars. Major changes of the Scientific Revolution and the 18th century included: