Webcam onlinexxx - Dating on the earth
This brings us to the impressive conclusion that Earth’s radius grew on average by 1.3834475 mm per year over the past 400 million years.
And so you can look back to that layer of bark just for the half life of carbon-14, and then figure out how much carbon-14 was there in the atmosphere at that period in time. Those are those speleothems that are kind of coming out of the bottom of the cave, or stalactites.
And so it's kind of a record of the atmosphere up to 10,000 years. Those are the speleothems that are coming from the top of the cave.
So I said maybe it's 5,730 years since this bone was part of a living animal, or it's roughly that old.
Now, when I did that, I made a pretty big assumption, and some you all have touched on this in the comments on You Tube on the last video, is how do I know that this estimate I made is based on the assumption that the amount of carbon-14 in the atmosphere would have been roughly constant from when this bone was living to now?
As is known from studies of 400 million year old fossil corals, Earth years were 400 days in duration in distant times because the Earth rotated faster than it does today.