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Comment by DINKDINK | Hacker News Reader

>...averages show they spots sit empty most of the time. But that type of analysis ignores the obvious fact that most parking is built to support peak times.

The word, that not enough technical and non-technical people know, that describes this issue is ergodicty:

> an ergodic dynamical system is one that, broadly speaking, has the same behavior averaged over time as averaged over the space of all the system's states in its phase space.

https://en.wikipedia.org/wiki/Ergodicity

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I'm not sure ergodic is what you're looking for here.

Ergodic is like a gas particle in a box. Over time, it'll have been at every position in the box.

Non-ergodic is like a house of cards. Eventually, it'll collapse and stay down.

Let there be a gas particle in a box. Now cut the box in half and if the gas particle can exist in all remaining space in the box, the box has had an ergodic transformation.

Non ergodic: Let there be a car on a major highway in a city. Now cut the roads on the highway in half (say for construction). Congestion results and consequently the cars never again move as fast as before. (equivalent to your house of cards)

  def ergodic(f(),x):
      return f(avg(x)) == avg(f(x))

Ah, yes, traffic is non-ergodic. I thought you were suggesting the opposite.

BTW, it looks like you've got a syntax error in your Python example.

Seems like a useful term to know. Too bad the wikipedia article is too dense to understand.

Consider editing the Wikipedia page to make the term more approachable.

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