[aspiretoreality]

Thanks for your sharing. Perhaps in the future once gravity is better understood, we will know if it can be depleted.

I imagine 200 years ago nobody worried overly much about burning coal or later, kerosene etc. The atmosphere is a pretty huge volume and besides, the rain cleans the air. ... one can imagine sentiments like that being directed at anyone complaining about air pollution.

[ramtatatam]

All pleasure is mine :-) I was hoping somebody would revise my post as it's almost 10 years since my uni physics course. I always enjoyed reading physics books though could mess up with details.