Lambda Definition and 102 Threads

Hello, I have a simple question. When reducing a lambda expression what happens in this case: (L x.y) (L z.z) (L z.z) -> y (L z.z) right? How to interpret the variable y in front? Is that normal form, or can I reduce it to just: y Or is the expression ilegal? Thanks

it has been stated that lambda interacts with gravity to give expansion,can anyone give the" mechanics" of this interaction?