Stamps from Afghanistan are hilarious. You can tell when the revolutions are because suddenly they stop having pictures of the mullahs and the independence monument and they start having fish on them.
It is sunlight in modified form which turns all the windmills and water wheels and the machinery which they drive. It is the energy derived from coal and petroleum (fossil sunlight) which propels our steam and gas engines, our locomotives and automobiles. . . . Food is simply sunlight in cold storage.