He has played a wide range of uncommon men: Captain Barbossa in the Pirates of the Caribbean movies, speech coach to George VI in The King’s Speech, and a brilliant, unstable pianist in the 1996 movie Shine (for which he won an Oscar). But Geoffrey Rush, 65, says that portraying Albert Einstein in the National Geographic television series Genius is “what actors call a great part. For a sexagenarian character actor, they don’t come along every day.” The 10-part series premieres Tuesday, April 25, on National Geographic. Rush spoke by phone from his native Australia; his interview has been edited for length and clarity.

How does an actor prepare to play a scientist whose theories and understandings were so far ahead of their time?

It’s scary! But of course the most interesting roles often are. First, I just try to relish the opportunity. I enjoy roles that involve a task outside of my natural capabilities—for example, playing a number of musical instruments, or sword fighting, or cutting a suit. You have to look as though you can do it, without too much editing. So I have to try and make you believe that I have his brain. In the series I’ve got massive slabs of dialogue so I had to understand the scientific principles involved and then fake it to credibility.

You could spend weeks online studying Einstein; there are millions of references. We found some delicious eccentricities about him because he was so down to earth. He liked wearing his wife’s shoes—if he couldn’t find his sandals, he’d just put on her open-toed slingbacks. I had a friend who studied at Princeton and folklore about him there is, he’d sometimes come in wearing a collar, tie, and jacket but he’d have his pajama pants on because he had forgotten or urgently had to get to a meeting.

In playing a role like this, you aim for a similarity and also to bring him to life as one’s own Einstein. And it’s important not to ignore the contradictions. He had a very bohemian youth, he rejected authority and rebelled against German militarism—but then he settled into a very comfortable bourgeois life. He had to confront all the horrific outcomes of where his beloved science placed him, up against his innate pacifism. He kind of got branded wrongfully as a father of the bomb; he was never really a major part of the Manhattan Project. They always went to him for advice, but wouldn’t give him security clearance because they thought he was possibly a communist, and because he was Jewish.

Einstein played the violin, was both scientist and artist. Do the two fields complement each other? Is there something of the scientist in you?

Einstein was very attracted to Mozart. There’s a mathematical, classical structure to the music and I think he identified with that very strongly. I think there also is a connection between being a genius and a polymath.

I’m a very amateur scientist. For me, it started with the Mercury space program and onward to the moon landing in my impressionable adolescent years. I dreamt of being an astronomer, I had a series of How and Why Books on the planets and the stars. At that stage, there were only 14 galaxies; now there are multiverses, dark matter, the nano-microscopic world of the interior of atomic structure. I’ve always been intrigued by the mathematical conundrum of the big bang: How did something come out of nothing? Because mathematically that can’t work. Einstein said the universe is so extraordinary that only God could have created it—and his job was to figure out how God did it.

Because of my astronomical leanings, I studied advanced maths and physics and chemistry up to year 12. But I flunked really badly because by then I had started running the school drama club. I still regularly read New Scientist to try to keep up with quantum theory and cosmological discoveries and so forth. And I read National Geographic—that’s not a plug.

WATCH: GENIUS TRAILER Get a sneak peek at Rush and newcomer Johnny Flynn as the older and younger Einstein in Genius.

Have you been in the presence of what you consider genius? If so, how did it manifest itself?

I had to consider the whole ideal of genius in my preparation for the role, and I found the most fantastic, pithy epithet from the philosopher Arthur Schopenhauer: “Talent hits a target no one else can hit. Genius hits a target no one else can see.” As I read about Albert Einstein, I thought, that’s absolutely a description of his mind, because he overturned 300 years of scientific orthodoxies—about gravity, light, space, and time, most importantly—from their pedestal.

As for whether I ever have met anyone who met that criteria: This is a performer’s response to another performer, but we have an amazing Australian actor and comedian, almost an old-school vaudevillian, who’s still working. His name is Barry Humphries but you may be more familiar with him from his character, Dame Edna, a self-styled international superstar. I’d say he’s hitting pretty close to the genius description because back in the 1950s, he asked cultural questions that others neglected to ask or even consider. He became a satirist of Australian suburbia and he distilled all of that into a dazzling, bravura range of characters. He did recordings, poems, sketches, and ended up with phenomenal national and then global success. He took London’s West End by storm—probably one of Australia’s first actors on that level—and then went to Broadway with his one-man show and was given an honorary Tony. On top of that, he’s also a painter and art expert. He’s been in the business since 1956 and is still going at age 83.

What separates an Einstein from the rest of us, and what might we and Einstein have in common?

View Images Geoffrey Rush, as Einstein, on location for Genius filming. Photograph by National Geographic/Dusan Martincek

When Einstein died they dissected his brain and found it was a normal brain weight—about 1.23 kilos. I think they were expecting to find he had a massive frontal cortex or something. He did have a very high IQ, 160—about the same as (theoretical physicist Stephen) Hawking. But I read that an 11-year-old English girl beat that, and got a score of 162.

What separates Einstein from the rest of us is, he had phenomenal focus on the gifts that he recognized would be his life’s work. He had a dauntless humanitarian drive. His celebrity as a theoretical physicist was huge—I mean, he was as big as Charlie Chaplin in that era, which for a theoretical physicist was pretty extraordinary. Another aspect of being regarded as a genius is endurance. He was still working on unified field theory into his 70s, and on his deathbed he was still trying to find what we would now call the theory of everything.

As for what we might have in common: He had a lot of human frailties. He had ego, on a level that all of us have at some point, possibly. He had doubt, sadness, many deaths in his lifespan, massive marital problems, estrangement from his children. He was vulnerable to all the sorts of contradictions that every human can be subject to.

Can you imagine yourself in conversation with him, or sharing a meal?

It’s a parlor game, really, isn’t it? The fantasy of having historical dinner guests. Now that I’ve delved a lot more into his life, he’d certainly be on my list alongside Plato, Shakespeare, Charlie Chaplin, and Queen Elizabeth I. I just hope he’d accept the invitation, because he was obsessed by the need for solace for what his exploratory brain demanded of him. But he was also gregarious; he quipped absurdities and made wisecracks like Groucho Marx. I don’t think he’d be daunting company. The point of his whole philosophy was to ask questions and I’d like to think he’d probably ask about me because he was quite mannerful in that way.

In terms of the meal: I have German ancestry, too, and I like schnitzel, strudel, my grandmother’s sauerkraut…So that’s probably what I’d suggest, and I think he’d join in heartily.