I am in a forum where there are two EU crackpot theorists that insist on the universe being infinite and static. Since the universe is 98.6% plasma; I asked them if plasma has mass. I am not a physicist but I know that a static universe cannot be if this plasma has mass as this would cause the universe to contract unless another force (dark matter) is acting in opposition and thus causes the universe to expand. I need a physicist to help me in my reply to these people! (Sorry I know this is an unorthodox request but we cannot allow such people to convince others of their crackpot theory.