It is a convention that the world changes and in all sorts of ways. The media tell us that we are in one such world and give us the impression that it is something new and easy. It is neither and never has been. Change in history might mean change of history.
If you want a real head banger to learn this try the link. It is about the last half of the 19th Century and is a Wikisource from a book about the development of steam propulsion in shipping. Just skip down the page and no questions will be asked.
It may seem arcane but what happened as a result of the changes was that the world shrank rapidly and by a great deal. What was possible for governments, business and others became the world of the early 20th Century with all its wars, ambitions and upheavals.
Just as technology and science shrank the world and shaped its history so now has the new internet and digital shrank history. The amount of archive material from a wide variety of sources in many countries coupled with indexing and other search provision is now vast and growing almost by the day.
Instead of a few learned and highly trained people who could travel to see and interpret what was held in guarded archives or such now anyone so inclined can have a look. Instead of the costs of travel and weeks or months going through the papers there are now the internet costs, a great deal cheaper and within the ability of many more to pay.
Picking out just one area of interest, the journals and newspapers of a period. I recall what a business it was wading through acres of the stuff in search of something, anything, that would be useful. For the Census Returns it meant London which was needed as well for the Registrar General's records.
The internet has coincided with the fact that the Census Returns from 1841 to 1911 in England and Wales are there, a huge store of information about the location and structure of society. You can go to any town or village, look around the streets and see what is what. Some of the possible would have been impossible before.
One matter in another part of history is the 17th Century Civil War. the basic story has been with us for a while and most attention is fixed on the major battles that occurred. What we see from the archive and other records is the extent of local actions where in the counties the War became a matter of landowners grabbing land, setting old scores and ruling by the sword for one side or another.
Across the country the War was not just the battles but years of running violence and a nastiness that make our present troubles with gangs look minor and petty in comparison. It was a world where you could not rely on or trust anyone almost anarchy in reality in the name of religion.
It is not surprising that so many fled to the America's. The trouble was that some took their bad habits with them. It wasn't too long before there was another Civil War, that of Independence for the USA, which led inevitably to another of the 1860's.
After two World Wars and a Cold War it could be that we are getting back to the old routines.