[ThinkPlease]

And how do you know those radio isotopes weren't created at a half-life? How can you be absolutely sure of this?

Because we've never once seen it happen EVER in the nearly infinite number of atoms that we've observed. Because it is an observable that the laws that are currently in effect in our reality are very nearly the same laws and constants that were in effect as far back in time as we can detect with instruments.

[chronic_loser]

And how do you know those radio isotopes weren't created at a half-life? How can you be absolutely sure of this?>>

Because we've never once seen it happen EVER in the nearly infinite number of atoms that we've observed. Because it is an observable that the laws that are currently in effect in our reality are very nearly the same laws and constants that were in effect as far back in time as we can detect with instruments.

Please go read David Hume.
I love responses like this. Here we are, with instruments to measure rates of radioactive decay for less than 100 years, and because we have some degree of regularity of data for that 100 year period, we are ready to state that it is a UNIVERSALLY TRUE STATE that potassium has a half life in the six to eight power.
Sheesh, talk about FAITH!!!
You have NO empirical evidence to assume that this is a constant. NONE. All you have is probability.
And probability sucks when you are making comprehensive statements about the nature of the universe.

[Right in Wisconsin]

are currently in effect in our reality are very nearly the same laws and constants that were in effect as far back in time as we can detect with instruments

And how far back in time can your instruments detect?