Ok.. Got a little bit information about Binomial Formula.. I will try to understand that further from wikipedia or any other websites and then i will...
What is this spectral lines of atoms and how it relates to the different orbitals? Are you saying singlet represents only one spectral line of atoms...
well,i think by 'real' time,he is talking about proper time. And indeed proper time dosen't change as it is the part of time-like invariant interval...