[dotancohen]

  > How does an aged post on this site go from +4 to -1 in the span of a few minutes?

Oh, I can answer that one. It's happened consistently to me on HN when I post about a specific topic.

First, the post looses two points at once. When I see that, I know it's going to continue losing points consistently until it settles into -2 to -4. There is some trigger that starts with a loss of two points, and then continues down.

[saltcured]

Addressing the "aged" part, I think people forget that timezones exist and so different global audiences may wake up and add their votes on a long-running comment chain here.