100
xkcd #3205: Carbon Dating
(imgs.xkcd.com)
Title text:
This dating is corroborated by the presence of stone tools at the site, rather than earlier and less effective helium ones.
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3205/
They'll probably date bones in the future by how much plastic is in them.
in where
Bones