Albert Einstein is known as the "father of modern physics." His revolutionary contributions to physics in the early 20th century transformed the field, particularly through his theories of relativity. The Special Theory of Relativity (1905) introduced the famous equation E=mc², linking energy and mass, while the General Theory of Relativity (1915) reshaped understandings of gravity. Einstein's work paved the way for numerous advancements in science and technology, influencing fields such as cosmology, quantum mechanics, and even technological innovations like GPS. His intellectual legacy continues to impact scientific thought today.