He was a great English theoretical physicist of over a century ago.
He is one of the world's leading theoretical physicists today.
Theoretical physicists tend to do their best work at about age 26.
It's a simple thing; you don't have to be a theoretical physicist to figure it out.
There is a simple answer: I'm not smart enough to be a theoretical physicist.
The author, a theoretical physicist, concludes that it may one day be possible.
These will be the outstanding problems for theoretical physicists in the next twenty years or so.
But within the community of theoretical physicists, he's kind of a major god.
In autumn 2004, she was the most cited theoretical physicist of the previous five years.
"As of last autumn, she was the most cited theoretical physicist in the world during the previous five years."