Ultimately it is about the price of energy. We're at a point where the price per Joule of fuel suitable for all kinds of transportation is the lowest it's ever

Ultimately it is about the price of energy. We're at a point where the price per Joule of fuel suitable for all kinds of transportation is the lowest it's ever been, affordable to an unprecedented number of folks. I often wonder about a hypothetical civilization that might arise in the future if the current one breaks down due to war or some natural disaster. How will it develop without access to easy oil and ores? Perhaps it will be a more thoughtful and humble civilization, and maybe the limits of its world will not seem so small as they do today.