Apparently Newton's law of gravity doesn't account for the way planets and stars effect each other.
So it is a bit like the explanation of how atoms are made up that is given to children; atoms do not really look like miniature solar systems, reality is a bit to complicated so a simpler model that is easily understood is given.
If this is not really how atoms look but you tell children that it is, then you are lying to children according to Terry Pratchett.
There are lots of examples of this such as how is a rainbow produced or the explanation of how a PN junction works.
