Einstein's last message was a dire warning against nuclear war that's still relevant today. Here's what it said.

•  Einstein urged Roosevelt to fund uranium research, fearing Germany would develop an atomic bomb.
• After the war, the physicist expressed regret for his role in developing the bomb.
• His final public act was to sign a manifesto warning that H-bombs could destroy humankind.

Shortly before his death in 1955, Nobel Prize winner Albert Einstein signed a manifesto written by philosopher Bertrand Russell.