Link thanks to andrewducker.
This is a 10 minute rant about the difficulties of establishing timelines if you (poor fool!) use what humans tell you about when something happened. He's not talking about the vagaries of memory. The problem is time zones, which are arbitrary and political and vary in more ways than I could imagine.
I'm not summarizing the video because it's fairly concise and it builds nicely, but if you want to know more or use text, have some wikipedia. Time on a ship.... there are ideal time zones at sea, but in territorial waters, the ship will use local time zones.
France has 12 time zones (has territories), Russia has 9 time zones, China has 1 time zone. Other oddities.
And then, of course, he gets into calendar changes, though mostly Gregorian/Julian.
And leap seconds, which are handled in several different ways. Do listen to the end, where he explains the Google leap smear.
I have a new theory about the Fermi paradox. All traces of civilizations get destroyed by programmers, who feel that the only possible kindness to fellow programmers (including alien programmers who might try to code aspects of civilizations) is to just not face them with the problems of keeping things straight.
I first ran into a discussion of this sort of problem in an article (possibly by Barbara Tuchman, probably in the late 70's) about medieval chronology. One of the fundamentals of history is to know what happened before what-- otherwise, you can't possibly talk about causality. however, any sort of unified calendar didn't happen until relatively late. Before than, people tended to talk in terms of reigns of kings. Have fun comparing between kingdoms.
This gets us to Wolfram Alpha which looks to be a delightfully powerful search engine/computer language. It's connected to huge amounts of information and computational power, so you can just ask it to show you a tour of all the capitals in South America, and it will give you a map with a route. It does math! It makes animations! Seriously, it looks to be both fun and useful.
My first twitch is tragically old school. If you're doing something important, do you want to be completely dependent on your connection working? Well, people depend on the cloud, and I depend on the cloud, and I'm sure there's some sensible way to think about when you should and when you shouldn't depend on the cloud.
My second twitch is probably better founded. I was looking at the South American tour, and thinking, but what if some country changes its boundaries? This doesn't happen often, and I have no particular expectation that it will happen any time soon in South America, but it does happen. Reading a little further about Wolfram Alpha, they reassure me that it's updated. How can I be sure that the updates are current and accurate? Good question. I don't even know if there's a good way to automate the idea of "data may be messy, you might want to check".
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