(May 21, 2012 at 4:08 pm)Alter2Ego Wrote: And where did the scientists get the 3.5 billion years? They just pulled a number out of one of their hats?
The date comes from the oldest know stromatolite fossils.
Controls on development and diversity of Early Archean stromatolites
They were found at the 3.4 billion year old Strelley Pool Formation in Western Australia. The formation they are found in was dated using U–Pb zircon method.
THE 3426–3350 Ma STRELLEY POOL FORMATION IN THE EAST STRELLEY GREENSTONE BELT: A FIELD AND PETROGRAPHIC GUIDE
If you are interested in how that works please read Dr. Roger Wiens’ article Radiometric Dating: A Christian Perspective.
So the answer to your question is no; They didn't just pull a number out of their hats.
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