I am one of those old codgers that sometimes get put down on these forums. But I'm a nice guy!
I was recently asked a question about interlacing that I simply don't know the answer to.
In analogue each field is a partial image separated in time by 1/60th(approx) of a second.
In progressive digital each frame is a complete image of a single instant in time and displayed 1/30th of a second apart.
Now interlaced digital; are the two fields partial images of two different instants in time that are separated by 1/60th of a second, or are they partial images of the same instant in time but displayed separated by 1/60 sec?