Student follows half of course by old doctor, a French physicist (7)

'a french physicist' is the definition.
(I know that Coulomb is a physicist)

'student follows half of course by old doctor' is the wordplay.
'student' becomes 'L' (learner, as in L-plates for learner drivers).
'follows' is a charade indicator (letters next to each other).
'half of' suggests halving the letters.
'by' is a charade indicator (letters next to each other).
'old doctor' becomes 'omb' (I can't explain this - if you can you should believe this answer much more).
'course' with half the letters taken is 'cou'.
'l' put after 'cou' is 'coul'.
'coul'+'omb'='COULOMB'

Can you help me to learn more?