What does physical or chemical castration even mean?
Physical castration is being neutered, aka what we routinely due to male animals we don’t intend to breed.
Chemical castration is essentially being chemically neutered - hormone blockers. Whenever you see someone anti-trans talk about pro-trans people wanting to chemically castrate children that’s why - it’s the same drugs being used to achieve the same effect - blocking sex hormones.
And why is this a punishment when he is 100 years old?
Because castration in LA is only performed in the final week of the prison sentence (presumably because it can’t be reversed so as to allow time for appeals), he was in his 50s when convicted and was sentenced to 50 years + castration. So by the time he’s in the final week of his prison sentence he would be over 100 should he live that long.