The question is slightly ambiguous. It could refer to:
1. The Etymology of the Word "Physics"
The word "physics" has its roots in the ancient Greek word "phusis," meaning "nature." Therefore, "phusis" could be considered the original name. A Quora response What is the full name of physics? - Quora states that "'Fusis' is the original name of the word Physics."
2. The Real Names of Physicists
The question might also be asking for the real names of specific physicists. Many physicists use pseudonyms online or are only known by their initials, e.g., Qmechanic Can anyone advice the real name of "Qmechanic"? - Physics Meta .... Other physicists, like J. Robert Oppenheimer J. Robert Oppenheimer - Wikipedia, are well known by their full names. The provided links showcase various examples.
To answer this aspect, more information about which physicist is being referenced is needed. For example, the real name of a person named "Jack" in the Samurai Jack TV series is not explicitly revealed in the series What's a good real name for Jack? : r/samuraijack.
3. Physics as a Field of Study
Physics, as a scientific discipline, doesn't have a "real name" other than Physics. It is considered "the fundamental science" because other sciences build upon its principles [Physics is also called as "the fundamental science" because all branches of natural science like chemistry, astronomy, geology, and biology are constrained by laws of physics. 'Fusis' is the original name of the word Physics.09-Jun-2018]. Physics aims to describe the real world through mathematical models Physics - Wikipedia.
