"All through our history, we have been changing the world with our technology. Our technology has been of two kinds, green and grey. Green technology is seeds and plants, gardens and vineyards and orchards, domesticated horses and cows and pigs, milk and cheese, leather and wool. Grey technology is and steel, spears and guns, and oil and ectricity, automobiles and airplanes and rockets, telephones and computers. Civilization began with green technology, with agriculture and animal-breeding, ten thousand years ago. Then, beginning about three thousand years ago, grey technology became dominant, with mining and metallurgy and machinery. For the last five hundred years, grey technology has been racing ahead and has given birth to the modern world of cities and factories and supermarkets. The dominance of grey technology is now coming to an end."