Sometimes apparently small things can change the world.
Why is it that world population started explosive growth around 7 to 8 centuries ago? Here's what it looks like to me.
Johannes Gutenberg is credited with the invention of movable type printing press. Printing with screw-driven presses already existed in the Chinese cultural sphere Wholesale Jerseys Cheap , at least a few centuries earlier. Movable type did not mean much for languages that used picture ideograms rather than alphabets. Gutenberg was a goldsmith, and knew enough metallurgy to develop casting methods for mass production of high definition characters. So, suddenly, the Western World had a means for mass production of printed text. No longer did a copy of a book take years to make. The spread of knowledge, not limited to Gutenberg bibles, was explosive.
Another part of the story was vision correction.
Lenses were probably invented in East Asia, many centuries ago. The first might have been made from found clear quartz crystals. Later, lenses of man made crystal (glass) shaped by grinding and polishing were developed. Simple magnifying glasses existed at least two thousand years ago. Various references say that Europe learned about lenses from books translated from Arabic and Indian languages. By about 1300, glass-making centers of Venice and Florence had achieved relatively cheap glass plus techniques for grinding and polishing. This led to affordable magnifying glasses and development of practical telescopes.
It is not known who first thought of adapting a generic magnifying glass to custom prescriptions, nor who first put two lenses in a hand held frame. Somewhere Wholesale Jerseys From China , about 700 or 800 years ago, someone invented spectacles, and the nose to hold them up. Around 1784, Ben Franklin dealt with his continued aging vision by inventing bifocal spectacles, so he did not need to keep swapping mono focal eyeglasses.
Just why was vision correction so earth shaking?
Consider that all trades and professions used to be passed between generations by the apprenticeship system. As practitioners of some skill achieved the status of "master", they took on young persons as apprentices to learn that skill, as well as to chop wood, haul water, and do the numerous aggravating chores the master could name as time wasters. The learned appentice became a journeyman, who might actually be producing the swords Wholesale Jerseys China , alchemical solutions, medicines, paintings, et cetera attributed to the master or "the school of master Xyz."
This process of becoming a master took many years, and was in close competition with the aging process. Feel sorry for the hunter approaching middle age who lost his distance vision, the jeweler or silver smith who could no longer focus closely, and so on. With spectacles, the professional years were extended, even to people who would previously have been unable to see well at all.
Low cost printing and cheap glasses enabled the explosion of knowledge, which led to the Industrial Revolution.
Unintended consequences include population explosion Wholesale Jerseys , explosion of the use of energy, exponential growth in pollution, hence Global Warming.
It's too late to un invent eye correction and printing. We had better learn how to control world population humanely, or the Four Horsemen of the Apocalypse (Famine, Pestilence, War, and Death) will ride the Earth.