People are always talking about the lasting impact of investing in science, but how far does the government dollar really stretch? At least 15 years, according to this graph on astronomy grants by University of Washington grad student James R. A. Davenport. Using data from the Harvard-Smithsonian Center for Astrophysics, Davenport charted  and color-coded the number of papers published each year based on National Science Foundation grants to astronomy research. Turns out, discoveries are still being made based on grants from at least the mid-90s. Most papers were published two to four years after the date of the grant — that's the dark band at the bottom of the chart — but even 17 years out, there is usually at least one new paper published each on that old research. "It's very encouraging that the grants awarded today will still be producing usable science well into the next decade!" Davenport writes.

Chart from IfWeAssume.com via reddit.com