It is common to see the Coriolis force described as "making it look like a force is acting upon the object, but actually there is no real force acting on the object". This prompts the question, "what is a real force"? From the viewpoint of general relativity, all coordinate systems are equivalent in describing physical processes, but in changing from one system to another things that look like forces will arise. For example, at the surface of Earth it is possible to (locally) remove the gravitational force by changing to a coordinate system accelerating towards the centre of Earth. But no-one would call gravity "fictitious".
Good scientific explanation:
http://www.physics.ohio-state.edu/~d...du/newcor.html