He is an expert in applied physics.

He is an expert in physical anthropology.

He is an expert in physical anthropology, conducting research on human evolution.

Gestalt psychology is an important means to understand human cognitive processes.

He is an expert in computational linguistics and is involved in the development of artificial intelligence.

He explained the importance of studying while young, saying 'If you do not study when you are young, it will be difficult to learn when you are old.'