When did modern technology begin in a certain time?

The idea of modern technology being defined by a period of time is an arbitrary one. Basically a few "authorities" or who ever is in charge at the time devices what goes on the timeline of events in world history.

Take history book from the US, Europe, Russia, Germany, Australia, and a few other countries, and look at the coverage of World War 2, and you will see that each book will have a widely different explanation of what happened.

Technology advancement is more like a gradient. There is no single moment when everything just changes. The periods of time that define the level of technology are largely based on politics.

If you would like to get closer to a more accurate way of defining a period of time that marks a transition in technology, then you will have to look at research on trigger points.

A documentary that better explains this is called the trigger effect where researchers attempt to find the root of modern society.

YouTube.com/watch?feature=player_detailpage&v=OcSxL8GUn-g