ISSAC NEWTON'S THEORY OF GRAVITY (1666 CE/AD)🔗

This comprises three interrelated theories: Newton's first law = object will not change its motion unless a force acts on it; Newton's second law = force equals mass times acceleration; and Newton's third law = for every action there is an equal and opposite reaction. Newton's theory is a discarded theory today as it fails to fully explain physical phenomena like partial reflection, refraction, diffraction, polarization, interference, changing speed of light in changing medium, and particle emission that does not change mass.