I'm wondering why we have a 12 hour system of clock and when this became popular. Thanks!

I understand that books and articles are scattered everywhere but is there a data base where you can find a lot of articles?

This occured to me after watching a cold war documentary. Obviously it's extremely useful for historians, but why minutes are kept? Is there a law that mandates that? And for what reason?

ps: I posted the same question a year ago and didn't get any answer :(

I know that in some cultures the left hand is seen as unclean, but what about European or Asian cultures? Where does this superstition come from?

I'm guessing it may have been to do with things like advancements in medicine not having occurred during the 19th Century. Could someone expand on this please?

What about things like the emergency services such as on organised ambulance? Did that make it worse?

Finally, how about things like weaponry and Napoleonic tactics?

If someone could shed some light on this it would be great.

Thanks in advance.

somebody knows the connection between the dictatorship in brazil and the usa government? I know a little bit about it but you would like to know more about.

I'm fascinated by this Colonel Kurtz-type figure that set up a kind of Buddhist state in Ourter Mongolia during the Russian Civil War. I'd like some reading recommendations, preferably something that isn't too pop-history but is still accessible enough to be read by someone who is outside the field.

Is James Palmer's Bloody White Baron: The Extraordinary Story of the Russian Nobleman Who Became the Last Khan of Mongolia any good? The title seems a little sensationalistic.

This is something I've always wondered, as it surely couldn't have been widely anticipated, at the outbreak of WW2 in Europe in 1939, that the coming conflict would end up eclipsing WW1, particularly given how deleterious an impact that war had already had in the not-then-too-distant past. I've always wondered when the idea first started to be seriously circulated in various places and arenas that the war they were engaged in was going to end up being even bigger - more destructive, more lethal, more widespread, etc - than the previous one. My presumption is that this realisation has to have happened during the war, rather than after it - one could hardly fail to grasp quite how mammoth a conflict was going on, circa 1943 for example.

By that I mean how long after the invention of baseball did it take for people to start asking "have you gotten to first base with that girl yet?" and questions similar to that.

I was wondering if the French did develop their own type of armour like the Germans did with the Gothic and the English with the Greenwich, but I can't seem to find any, which seems strange with France being the land of chivalry and all that.
Edit: I somehow confused Greenwich with Cambridge.

Were there any driving instructors at the time? Or were people told how to operate the vehicle and just left to go about their day?

Everything is in this weird hundreds of millimeters or thousands of inch tolerances, and it just baffles me. Why .308 instead of .300? 5.56mm? Why not 5mm or 6mm? And, I know it's the same size as .223, but still, why not .25? It's all this weird mishmash of calibers, and that's not even discussing the weirdness of round length.

At the moment, there are only a couple of tiny patches of land that aren't claimed by countries (such as Bir Tawil) but there must have been a point in time where there were significant unclaimed tracts of land. I know that the definition of "claimed land" might be a bit fuzzy but approximately, when was all "useful" land (e.g. excluding Antarctica) on Earth claimed by countries?

I'm supposed to have a handle on Art of the Renaissance, and I do for the most part except for a few; one being the Meat Stall. I have a few questions - Economic, political and cultural reflections of the art, how does the artist represent the ideals of the Renaissance, how has the art been used in popular culture OR how COULD it be used in popular culture? If anyone can help, thanks ;)