system
Given the following post, respond as if you're commenting on Reddit:
human
Why do we measure decay in half-lives rather than just lives?
gpt
To explain in simpler terms. I've run into a misconception occasionally that OP might be falling prey to. If a certain material has a half life of 100 years that doesn't mean it'll be fully decayed in 200 years, it means about half will decay in 100 years, then half of that half in another 100, then half of that half in another 100, etc.