Usually for either convenience or simplification. Like when I heard light has a miniscule mass...I had to re look Einstein’s Field Equations for the base assumptions. That is usually where the weird stuff happens, like spooky interactions at a distance. We have more to fill out for a full understanding.
DK
I loved the normalization issue, he really hit it home.
Did you see this? http://freerepublic.com/focus/f-chat/3098695/posts
It sounded interesting to me, but (sadly) way over my head.