German physicist Albert Einstein was born #OTD in 1879.
Best known for developing the theory of relativity, he also made important contributions to quantum mechanics. He was awarded the Nobel Prize in Physics in 1921 for his explanation of the photoelectric effect, which contributed significantly to the foundation of quantum theory. He was also a prominent public figure & advocate for pacifism, civil rights, and social justice.
Albert Einstein at PG:
https://www.gutenberg.org/ebooks/search/?query=einstein&submit_search=Go%21