How Do We Know? The Value of Scientific Models.

Last month, astronomers announced the prediction of a new giant planet in our solar system dubbed Planet IX, a genuine ninth planet with ten times the mass of Earth.  The announcement lead to some confusion on the Internet as to the whether the planet had actually been discovered.  In fact, no direct observation of this planet has been made. Rather, the planet has been predicted by a model, a simplified description of a system which often incorporates hypothetical elements to explain the variance in data.  Because many models use equations to describe a system, a model can often be thought of as a theory with a mathematical backbone.Continue reading