The show, Genius, airs on National Geographic, and Rush tells NYT that he’s always been drawn to playing what he calls ‘outsiders:’

“I suppose I’m drawn to — I’d call them all outsider figures. In my theatrical repertoire, I rarely played the central character. I was not the young heroic model for “Hamlet.” I tended to play those characters that orbited around them: the rogues and the rat bags and the idiots and the fools and the clowns that sway the plot somehow from a tangent.”
And what made him think that he could play Einstein in particular? Well, the answer is certainly amusing:
“I got a classic photo of the older Einstein. And I got a friend to take a photo of me and morph 15 percent of Einstein into my photograph to give me an indication [of how] to create a credible likeness. Then I got out a [marker] and put in the eyebrows, and some Wite-Out, and I drew in the halo of the hair. So that was my own audition for myself. I sent it to Ron [Howard, director] and said, “I think we can do this.””
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