The letter warned that Germany could develop "extremely powerful bombs" using uranium and urged the president to "speed up" the US's own work on the element, eventually leading to the Manhattan ...
Though Einstein was never a part of the Manhattan Project — the US Army Intelligence Office denied him the necessary security clearance — the Nobel Prize winner regretted his role anyway.
eventually leading to the Manhattan Project and the development of the world's first atomic bomb. Though Einstein didn't write the letter, his worldwide esteem meant his signature added ...