Dating methods

Well, we base a lot of dating on the radioactive decay rates of various elements. And we know those rates have been constant for about 2 billion years because of astronomical observation.So I'd say radiometric dating is pretty accurate, when you follow the right procedure. Like any scientific test you get bad results if you do it wrong.

You use multiple dating methods and multiple attempts. If your dates all converge, you know you did it right. If you did it wrong, you get divergent dates, because different methods give different errors if you do it wrong. Well, you can't know the truth about if Nero or Lincoln existed, because you weren't there. On the other hand we can be as sure that our dates are correct as we can that Abraham Lincoln actually existed. That's good enough for me.