Wouldn’t most of the water today have been formed at the same time when the hydrogen was initially oxidized?
What am I missing here?
Since water moves, I would say that where it is, is not necessarily where it was.
/johnny
“Wouldn’t most of the water today have been formed at the same time when the hydrogen was initially oxidized?”
The answer is no, water molecules are constantly being destroyed and recreated by a wide variety of inorganic and organic chemical reactions. When the younger water molecules are recreated using younger isotopes of oxygen, the new water molecules acquire a younger isotopic signature. To retain the older isotopic signature, a water molecule must be isolated in an environment in which the molecule remains unchanged and retains the its original atoms.
I’m not sure how one dates water, but most of the water on earth is now believed to have come from comets which collide with earth on a regular, but diminishingly frequent, basis.
Uhhh...let's see...well since CO2 is a greenhouse gas (even though greenhouses are made out of glass and it's an insulator) and the Earth is getting hotter by the second (although we're having the coolest spring in decades) car pollution and cows farting are destroying the water supply that normally gets regenerated every 6 months. So you have to stop drinking water that wasn't brewed a million years ago, besides, if you drink "older" water you're cooler than everyone else...like if you drive a hybrid!
I think that the reference here is that is has not been cycled through the atmosphere/oceans/ground for 1.5 billion years.
Now, what difference it makes escapes me.
Exactly. they might mean it's water that hasn't seen sunlight in umpty-ump years, but it's the same age as all the rest of the water in the world.