Who is credited with the development of the theory of relativity?

The development of the theory of relativity is primarily credited to Albert Einstein, who published his groundbreaking work in the early 20th century. The theory consists of two parts: special relativity and general relativity. Special relativity, introduced in 1905, revolutionized the understanding of space and time by positing that the laws of physics are the same for all observers, regardless of their relative motion. General relativity, published in 1915, further expanded on these ideas by describing gravity as a curvature of spacetime caused by mass.

Einstein's theories fundamentally altered the way physicists understand the universe, providing insights that have been confirmed through various experiments and observations, such as the bending of light around massive objects. His work laid the foundation for modern physics and has had profound implications across various scientific disciplines, including cosmology and astrophysics. This historical and scientific significance makes Albert Einstein the correct answer for the question regarding the development of the theory of relativity.