Conversation so far:
Who was Fischer's father?
Sources implying that Paul Nemenyi, a Hungarian-Jewish mathematician and physicist and an expert in fluid and applied mechanics, was Fischer's biological father.
Did Paul Nemenyl have any great achievements?
CANNOTANSWER.

Question: What roles, besides father, does Paul play as Fischers father?
Self-contained rewrite: What roles, besides father, does Paul play as Fischers father?