No, Albert Einstein was awarded the Nobel Prize in Physics in 1921 not for his theories of relativity, but for his explanation of the photoelectric effect. His work on the photoelectric effect provided important proof for the quantum theory by demonstrating that light energy is carried in discrete quantized packets. This discovery was crucial in the early development of quantum mechanics. Although Einstein's theories of special and general relativity are among his most famous contributions to physics, it was his insights into the nature of light and the photoelectric effect that were recognized by the Nobel Committee.
