The title "father of modern physics" is often attributed to Sir Isaac Newton. His work in the 17th century laid the foundation for classical mechanics and universal gravitation. Newton's laws of motion and his formulation of the law of universal gravitation revolutionized our understanding of the physical world and set the stage for further developments in physics.
While Galileo Galilei made significant contributions to physics in the 16th and 17th centuries, including his work on kinematics and the development of the scientific method, he is usually referred to as the "father of modern observational astronomy" rather than the father of modern physics.
Albert Einstein, on the other hand, is considered one of the greatest physicists in history and made groundbreaking contributions to the field with his theory of relativity and his work on the photoelectric effect, for which he received the Nobel Prize in Physics in 1921. However, Einstein's work built upon and expanded the foundations laid by Newton rather than challenging or replacing them.
While all three figures—Newton, Galileo, and Einstein—played crucial roles in the development of physics and our understanding of the natural world, the title "father of modern physics" is most commonly associated with Sir Isaac Newton for his foundational contributions to classical mechanics and universal gravitation.