Between ~1880 and ~1920, the physical sciences made huge, crazypants leaps both in theory and experimentally. The rest of the 20th century was spent catching up

Between ~1880 and ~1920, the physical sciences made huge, crazypants leaps both in theory and experimentally. The rest of the 20th century was spent catching up with all the implications of those leaps. Now, the sciences have a set of very powerful ideas that have a bad habit of producing the right answers as far as anyone can see, but which have very visible holes and don't fit together. Thus, stagnation. On the other hand, it may just be a return to the normal status quo.