> but that doesn't mean it's 'dark' or even 'matter' or even one single thing An important addendum to this is that it really does look an awful lot like matte

> but that doesn't mean it's 'dark' or even 'matter' or even one single thing An important addendum to this is that it really does look an awful lot like matter that happens to be dark...or to be more specific, electromagnetically inert. That's not to say it has to be, of course we don't know for sure, but I see a lot of people on the internet apparently quite certain it's not matter at all - often for not very good reasons, or via arguments that aren't remotely that strong.