Dark Matter: The Situation Has Changed
An article on HN a couple months ago <a href="https://news.ycombinator.com/item?id=26442021" rel="nofollow">https://news.ycombinator.com/item?id=26442021</a> claims that our theory of gravity is perfectly fine, we just haven't been taking into account the proper relativistic corrections at galactic scales. This seems much more plausible and elegant of an explanation to me.