[ozmbie]

It mentiones why this is useful:

> it will give scientists a much more accurate method of dating prehistorical events — the dates of fossils, for example.

> “The dream is have a framework independent of the fossils that you can plug the fossils into and see more interesting things — the coexistence of disparate forms, or of similar forms widely separated in location. Now we can place things more accurately in time rather than depending on the fossils to tell us what the time is.”

It's also fascinating to see how it was done:

>By comparing the amount of decay of uranium to that of lead trapped in zircon, the layers in the Arizona core can be dated quite accurately.