MW Governor FitzGerald Refuses to State How Old the Earth Is

[angus]

MW Governor FitzGerald Refuses to State How Old the Earth Is

Good for him.  Anybody who tells you that he was there at the beginning is either a liar or a god, and since gods only exist in the minds of people, that pretty much narrows it down.

FitzGerald doesn't say how old it is because he doesn't know how old it is.  Neither do I.

[angus]

I think 4.6 billion years is a good estimate.

I think 4.5 billion years is a better estimate, if you're going to use radiometric dating.  Actually, the oldest Earth rocks are only about 3.96 billion years, and the stuff that's over 4 billion years are meteors and other extra-terrestrial.  These trends come and go.  Lord Kelvin calculated a date based on cooling through conduction and radiation and decided the earth was 30 million years old based on the laws of thermodynamics.  Later Rutherford decided, based on isotopic dating, that it was maybe 500 billion years.  We're up to 4 billion now.  (4.5 billion?  Can we honestly claim two significant figures?!)

But why quibble over such things?  It all seems pretty far removed from the cost of a loaf of bread or a gallon of fuel.  Certainly the governor has more pressing issues to occupy his time.