writing_page cave_painting writing metal_movable_type_printing powerloom_weaving writing_defined printing_press George_Stephenson industrial_revolution compulsory_schooling complexity writing_allows_complexity literacy_and_basic_skill puffing_billy early_steam_engines The_Engineer_and_Engineering pelton_wheel turbine_development models_and_mathematics computer_control program_text wrong trivial_error trivial_error_list proof_reading phonetic_spelling Dr_Johnson Noah_Webster diversity_of_English pre_dictionary_spelling spelling_and_acceptance spelling_and_POS brevity oversimplifying simplifying error change Fritz_Machlup education_spending school_leaving_age leaving_age_raised huge_growth_higher_education better_educated_population rate_of_technical_change switch_from_grant_funding half_life_of_information Python technology technological_change social_upheaval