There are many factors, such as the source, the identification or the definition of the mouth, and the scale of measurement of the river length between source and mouth, that determine the precise meaning of ''river length''. As a result, the length measurements of many rivers are only approximations (see also coastline paradox). In particular, there has long been disagreement as to whether the Nile or the Amazon is the world's longest river. The Nile has traditionally been considered longer, but in recent years some Brazilian and Peruvian studies have suggested that the Amazon is longer by measuring the river plus the adjacent Para estuary and the longest connecting tidal canal.
Based on the above text, what's the best answer to this question: is mississippi the longest river in the world?
no