[deathhand]

It took us a long time to figure out 0. This idea of multivariate time series is "tacit knowledge" and once we get good at modeling it we will never look back. As a laymen this is the most accessible I've seen these concepts.

And speaking for neurology methodology for time series tests subtraction sucks! https://www.researchgate.net/publication/12369885_How_to_Avo...

[dang]

Can you say more? What's "0" in this context?* and can you explain what the idea here is and why it's useful? I think quite a few readers would be curious.

(* I ask because I can't find anthing labeled 0 - but I may have messed up the URL - see https://news.ycombinator.com/item?id=34223587)

[deathhand]

I mean zero as in the nothing sense. We had trade and society before we had way to mathematically describe nothing. The history is diverse and interesting:

https://en.m.wikipedia.org/wiki/0

[pvg]

before we had [a] way to mathematically describe nothing.

This seems a little overstated since positional number systems are fairly sophisticated mathematics - you can deal with 'nothing' without needing zero in its modern sense.

[vanderZwan]

You can even have positional number systems without zero - that's what the Babylonians had