How have we achieved such an astronomical, exponential progression in such a short period of time?

After 5,500 years of recorded human history, with no evidence of other earth-like planets in the Universe, we have gone from discovering the first near-Earth-size planet a year ago, to finding one today that would only take 20 years to get to…
How have we achieved such an astronomical, exponential progression in such a short period of time?
Here’s the timeline:
Nov 4, 2013 – Data from NASA’s Kepler space observatory calculated that our galaxy “probably contains at least two billion planets th...