00:02
Hi there.
00:03
In this question, the scientific evidence to what they refer, to which they refer, comes from both geologists and astronomers.
00:17
So scientists from a couple of different branches of science.
00:22
And what they have determined, many of them through many experiments and much scientific evidence, they've concluded that the earth is approximately 4 .6 billion with a b, years old.
00:44
You might say, well, how do they know this? to determine this, they work with radioisotopes.
00:52
And they know the half -life of these isotopes, so they can look at rocks and things like that, and see how much of the isotope remains.
01:01
And from that, they can calculate the approximate age.
01:06
So what this is called is radiometric dating, where radioactive samples are measured in rocks, and from that, they can determine the approximate age of the rock...
