Choices of reference frame

Graphic - frames

A reference frame is a set of coordinates axes with respect to which we choose to chart the position (motion) of objects of interest.

Often we make the choice without really knowing we are doing so: we tend to describe things the way ‘we’ see them –effectively using a set of coordinate axes fixed in us!

But the choice of reference frame should generally be well-considered. A good choice may make the resulting description much simpler than a bad choice. Thus sometimes we may wish to think of a set of axes with an origin fixed at the center of the earth, or perhaps at the north pole. And sometimes (can you think of an example?) we might choose to think of a set of axes fixed on the sun.