What are the greatest scientific discoveries/accomplishments within the last 20 years that have propelled humanity (and our understanding of it) forward?<p>If necessary, can extend this to the past 50 years as well.
A bit older but seem relevant "Ask HN: What are the greatest discoveries in the last few years?" <a href="https://news.ycombinator.com/item?id=9731111" rel="nofollow">https://news.ycombinator.com/item?id=9731111</a>