Question

Who prospered the law of conservation

Answer 1

There is a scientific law called the Law of Conservation of Mass, discovered by Antoine Lavoisier in 1785. In its most compact form, it states:

matter is neither created nor destroyed.

In 1842, Julius Robert Mayer discovered the Law of Conservation of Energy. In its most compact form, it it now called the First Law of Thermodynamics:

energy is neither created nor destroyed.

In 1907 (I think), Albert Einstein announced his discovery of the equation E = mc² and, as a consequence, the two laws above were merged into the Law of Conservation of Mass-Energy:

the total amount of mass and energy in the universe is constant.