Re: Could this be the "missing mass"?
> we don't really know much about gravity
Thta's just fucking bullshit pulled out of donkey arses. The Einstein Field Equations have not shown a single hole in about a century of application. I strongly suspect this will stay that way until someone comes up with a viable description of quantum gravity.
> So we are supposed to believe in magically invisible stuff?
So we are supposed to have magically different behaviour of gravity under nicely left-unstated conditions?
I don't see what the XKCD strip adds either. Especially as it shows the Newton equation. Feck off.