Albert Einstein is a German-born physicist who is widely considered the most influential physicist of the 20th century. He is famous for his immense contributions to the field of physics and his theory of relativity, which revolutionized our understanding of space, time, gravity, and the universe. Some of his most notable achievements include:

• Theory of Relativity: Einstein developed a theory of special and general relativity, which helped to complicate and expand upon theories that had been put forth by Isaac Newton over 200 years prior.

• E=mc²: Einstein is best known for his equation E = mc², which states that energy and mass (matter) are the same thing, just in different forms.

• Photoelectric Effect: Einstein discovered the photoelectric effect, for which he won the Nobel Prize for Physics in 1921.

• Inventions: Einsteins discoveries and theories have led to the development of many everyday products, including paper towels and lasers.

• Advocacy: Einstein was a passionate advocate for peace and civil rights, using his platform to promote social justice causes and raise awareness about issues affecting humanity.

• Writing: Einstein published over 300 scientific papers and over 150 non-scientific works during his lifetime.

• Nobel Prize: Einstein won the Nobel Prize in Physics in 1921 for his explanation of the photoelectric effect.

Overall, Albert Einstein is famous for his groundbreaking contributions to the field of physics, including his theory of relativity and the equation E=mc², as well as his advocacy for peace and civil rights.