User:William M. Connolley/Fictitious force

'' As you see, I don't really like this concept at all. Scienceworld has no defn - it just links to Coriolis, etc. Compare fictitious force ''

The concept fictitious force is sometimes used to describe forces such as the coriolis force or the centrifugal force. The distinguishing feature of these forces is that they arise as "change of coordinates forces" when changing the frame of reference from an inertial frame to a non-inertial frame: the action of a fictitional force is inferred to explain the accelerations observed in the non-inertial frame. Due to this, fictional forces can be identified by the virtue of the strength of the force being directly proportional to the mass of the object it acts on: a property that they share with the gravitational force.

Within physics, there is no obvious use for the term "fictional", or even any precise definition. It is not clear that this characterisation is particularly useful, and many deny that forces are "fictitious" or "imaginary" in any real sense.

Simply characterising a force as fictitious because it arises from a change of reference is possible but has unexpected consequences. It is notable that in Newtonian physics gravity acts on all objects in direct proportion to their masses. Therefore gravity acts like a fictitious force, and in general relativity it is one, by this definition.