Chaotic Systems Are Fundamentally Deterministic

Jun 29, 2021 Last reply: 5 years ago 35 Replies

That's a bit silly. The Wimbledon centre court is specific and relatively small area. Weather radar can seem rainstorms moving across the city and provide a forecast of when the next rainstorm is going to hit the centre-court at Wimbleton.

The general public wants to know when a rainstorm is going to hit them, wherever they are.

Mobile phone areas in cities are pretty compact - if each cell tower pushed out it's own forecast to all the phones it was serving at a particular instant, it could do almost as well.

We have open-top streetcars too.

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I don't know who that Hayes guy is.

That's a pretty good idea - add a simple weather station atop each mast and you could warn people to get the washing in a little in advance.

And we'd have so many more temperature records.

But you gain forecasting time only logarithmically as you improve precision, and the initial conditions have quantum indeterminacy.

Cheers

Phil Hobbs

Or even a vanishingly small one, plus an indefinitely long time bouncing around.

Cheers

Phil Hobbs

That only works if you do an active *forecast* for each of those specific data collection points. I can count ~15 *networked* "personal weather stations" within a mile of my home. Temperatures currently reported vary from 85F to 89F.

One can argue that these aren't NBS-traceable instruments (and who knows how carefully they are sited), but I'd wager that there actually is that much variation in this small of an area (changes in elevation, vegetation, natural features, etc.)

E.g., the nearest hospital is ~2.5 miles as the crow flies. They will frequently have rain or even a dusting of snow (!) while we won't see either.

["Spring" comes to the south end of my street two weeks earlier than it does to my end -- just three blocks further north! (as evidenced by when the various flora bloom)]

Which one(s) should be used to forecast *my* weather?

Happily, billiard tables are lossy. The balls stop rolling eventually. If you put spin on the ball, the rotational momentum decays faster than the translational momentum.

I did play billiards with theology students from time to time, and they didn't do anything miraculous - they were Methodists, so they may have been restraining themselves.

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Mercury's orbit is highly chaotic over time frames of only a few tens of millions of years into the future, which isn't much on the scale of geological time. Measurement error of bigger than about an mm today will throw it off completely if you try to run that model 100 million years forward.

The weather here is chaotic on the scale of one day. The stock market is too.

The weather here was just as hot as the five-days-earlier forecasts told us. My stocks don't get traded on the scale of one day. Do yours?

What's your timescale measure algorithm? Does it take twenty-sided dice?

Weather report fort southeast Massachusetts on Sunday evening said there was going to be severe thunderstorms tonight 90% probability and there were, a real rip-roarer that went on for about an hour with lightning flashes like a Berlin discotheque. Brief thunderstorms and downpours are pretty common here during the summer but tonights was extra-spicy.

Power stayed up though, not even a flicker. the local utility seem to have been keeping the trees trimmed and tidy lately

Some accurately predicted big-ass cells moving thru:

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Someone probably going to post a nice picture of lightning strikes on the Pru and John Hancock towers on Reddit

The double-rod pendulum example in the link is fascinating.

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