We, humans, evolved from small stone-age settlements to modern metal & glass sky-scrappers. 4000 years ago, despite we had the same brain capacity, our behavior was not too different from animals. 500 years ago, we were still far away from what today modern civilization has. At that time, the Byzantine Empire was conquered by the Turks. If we travel in time and take to our days someone from 1500 to our days, that person will see demons running on the streets (instead of cars), stardust fallon on the Earth (instead of artificial illumination) and probably will have a heart attack when looking for the first time on a TV.