Good article. Interesting finding at the very end:

>Although the proportion of disruptive research dropped significantly between 1945 and 2010, the number of highly disruptive studies has remained about the same.

So... maybe this is because having more people doing scientific research doesn't yield more breakthroughs. More people doing scientific research DOES yield more incremental achievements, as the study found, i.e. word frequency analysis showing more occurrences of "improve", "expand", "extend".