scientific theories are mostly approved after they have been researched fully and can be backed up with evidence.
Explanation:It is less unlikely that the theory will change except that it can be improved when the new evidence is discovered due to the fact that they are based on discovered evidence.
Theory of gravity for example there is a proven evidence that there is a pulling force knows as the force of gravity that keeps us from floating on earth whereas in space the lack of that force causes one to float this is backed up by evidence that are visible and can be tested all over again.
