|The world as we know it ...|
Consider "Five Independent Signs Of New Physics In The Universe." If physics interests you, all five issues are worth a look -- but the item of most interest to me is dark matter. Bottom line: the behavior of such large objects as galaxies and galactic clusters doesn't fit with our understanding of gravity absent lots of unseen matter. If we do understand gravity -- the heart of general relativity -- then there must be lots of dark matter out there. But the standard model has no place for a dark-matter particle(s), and no search for dark-matter particles -- or for any particle physics beyond the standard model(*) -- has yet borne fruit.
(*) For example, super-symmetry or string theory.