Left hemisphere

If you study sitting up erect, you may be left lobe. The left hemisphere of the brain processes information from part to whole. In order to draw conclusions, it first takes pieces, lines them up and arranges them in logical order. When left-brain students read or listen, they look for pieces so that they can draw logical conclusions. They have no problem comprehending or expression oral or written language. The functions of the left hemisphere of the brain are verbal, rational, realistic, and rigid. Some problematic characteristics, which exist in the right hemisphere of the brain, are emotional comprehension and procession of symbols.
Left-brain students are verbal and have little trouble expressing themselves in words.

Albert Einstein
I think he used more the left hemisphere of the brain because he used more logical, realistic and rational information. It helped him on his career because he used it for his achievements as a theoretical physicist, philosopher and author who is widely regarded as one of the most influential and best known scientists and intellectuals of all time.

Stephen Hawking
I think he used more the left hemisphere of the brain because he had to use logical and rational conclusions in his career as a theoretical physicist and cosmologist, whose scientific career spans over forty years. Hawking was the Lucasian Professor of Mathematics at the University of Cambridge for thirty years. He is also a Fellow of Gonville and Caius College, Cambridge and a Distinguished Research Chair at the Perimeter Institute for Theoretical Physics in Waterloo, Ontario. He is known for his contributions to the fields of cosmology and quantum gravity, especially in the context of black holes.