(NYT) – Some experts are optimistic that science will eventually find ways to extend life, but many longevity claims are unrealistic.

Exciting as this is, much of this longevity work focuses on health span — helping people to live more healthily into their 80s, 90s and even 100s — rather than extending the human life span. Researchers continue to debate how possible that will be in the future. The problem is that their answers are often hypothetical and impossible to prove. (Read More)