The nature of the scientific method is controversial with claims that a single scientific method does not even exist. However the scientific method does exist. It is the building of logical and self consistent models to describe nature. The models are constrained by past observations and judged by their ability to correctly predict new observations and interesting phenomena. Observations do not...

Introduction Science is often described as a way of knowing about the natural world (the word science has its origins in the Latin verb for knowing) and most dictionaries define science as a body of knowledge dealing with facts and/or truths about the natural world. The emphasis is on the body of knowledge and on facts, with the implication that absolute truth is involved. This is often how sci...

So wrote Ibn al-Haytham (Alhazen), who was born around 965 in Basra (now Iraq, but then part of Persia), lived most of his life in Egypt, and is credited with being an early developer of the scientific method. His road to truth took a wrong turn that almost cost him his life. After claiming that he could use mathematical principles to regulate the flooding of the Nile—and later realizing that t...