Is theoretical physics stuck in a rut?

It does not seem that physics can get beyond the discoveries of the last century.

The problem of unifying relativity and quantum mechanics still remains. String theory seems to be the leading candidate, but its fate remains uncertain.

Cosmologists are making statements that I would find rather embarrassing. They say that there is this unknown dark matter that accounts for most of the Universe, but they don’t know where or what it is. They also say that by their calculations the Universe should be collapsing in on itself, so there must be some dark energy that is causing it to fly apart at about the speed of light. Nobody knows if there is just one Universe or infinitely many.

Is further knowledge possible? Can the LHC or a space telescope provide some missing information?