I've always wondered how can scientists can be certain about deep time, your explanation is easy to understand but not compromise the knowledge. Thanks!

great video!

How did someone figure out the half-life of potassium, or any of the other elements whose half-life is even in the tens of thousands of years? You are not going to get to one half daughter.

How about using chemical decaying times like rubidium and stronsium? would you mind to make a video about it? thank you

I lost all audio when the video shifted to half life demo.