Why Use Aluminum for a TT Platter?


Mass I am told is a good thing when it comes to TT platters. Lloyd Walker for one extolls it's virtues and as a rule some of the better turntables like to brag about their big ..Platters. Why then would aluminum, known for it's light weight (low density) turn up as frequently as it does as a platter material. I know it is easily machined but isn't there anything better and much denser.
mechans
The name of the plastic is Delrin, a DuPont trade name for polyoxymethylene. It is a homopolymer so it does not contain nylon, though there is a carbon molecule in it.

I know that Applied Fidelity makes mats out of the stuff for Technics 1200s and the like. You could call Jim Howard at Applied Fidelity if you are interested in trying Delrin based mats, as I believe that he will do custom cuts.
The idea of "big" or extremely heavy platters is mostly for use with belt drive tables which I believe, in terms of speed accuracy, are clearly inferior to properly implemented direct drive tables.

And yes, when it comes to belt drive, it is about inertia. "An object in motion remains in motion unless acted upon by an outside force".
Just look at the platter of the relatively inexpensive ($2k) Nottingham Spacedeck. It's a minimalist design table, and I bet that the platter alone costs at least half, probably more. I have no idea what it is made of but the thing is quite heavy. As I understand, that's what mostly makes Nottinghams sound the way they do - the platter.
Cooper with lead and steel in a sandwich style sounds good to me. And a beer please.
Viridian thanks for the trademark education but Michell platters are Carbon infused acrylic that DO contain Vynil.
Cheers
"Belt drives...in terms of speed accuracy, are clearly inferior to properly implemented direct drive tables."

Humm, proof, evidence to back this up?