On 12/28/20 4:06 PM, Matthew Petach wrote:
I think you may have misunderstood Keith's comment about it being "all a matter of time-frame."
He's right--when the sun consumes all the hydrogen in the hydrogen-to-helium fusion process and begins to expand into a red dwarf, that's it; there's no going backwards, no putting the genie back into the bottle, no "renewing" the sun. It's purely a one-way trip.
Now, as far as humans go, we're far more likely to be extinct due to other reasons before we come anywhere near to that point.
But as far as the physics goes, the conversion of biomatter into petrochemicals in the ground is more "renewable" than the conversion of hydrogen into helium in the sun.
It's just that we're far more likely to hit the near-term shortage crunch of petrochemicals in the ground than we are the longer-term exhaustion of hydrogen in the core of the sun. ;)
2020: Hawking Radiation, take me away. Mike