Discover a fast and powerful calculus-based method for finding square roots with impressive accuracy. This explanation shows how derivatives and iterative approximation can be used to quickly zero in ...

America faces an aging crisis: We have too few young people supporting too many older people — at the very moment Social Security, our national retirement program, nears insolvency. Why it matters: ...

We independently review everything we recommend. We may get paid to link out to retailer sites, and when you buy through our links, we may earn a commission. Learn more› By Kit Dillon Kit Dillon is a ...

For more on lying check out our podcast, “Overheard at National Geographic.” Listen here. This story originally published in the June 2017 issue of National Geographic magazine. In the fall of 1989 ...