Where would you draw a line between the world of pre and post? What year exactly? If it's so obvious and blatant, you should know. Sure, you can't date it, can you? Explosion of industrial revolution could be dated to later decades of 19th century. However, industrial revolution was going on in 18 and even 17 centuries. Industrialism as a concept has been born somewhere in 15-16 centuries. There was no bam, even though the western life was distinctively different in 15 and 19 centuries.