You might be most familiar with sonography's role in the field of obstetrics to produce an ultrasound image of an unborn baby. Sonography is also used to analyze tissues and organs of the body, such as the heart, eyes and abdomen.
Etymology: Pierre S. de Laplace, French physicist, 1749-1827. a principle of physics that the tension on the wall of a sphere is the product of the pressure times the radius of the chamber and the tension is inversely related to the thickness of the wall.
The Law of Attraction and the Law of Reciprocity can seem to be one and the same but LOA is the law that makes certain that something is attracted and reciprocity determines what that something is which is based on what you put out there.