[WebHubbleTelescope]

Over 50 years have elapsed since Hubbert sketched the first Logistic curve to describe oil depletion. It was also over 50 years ago that scientists observed the odd "anomalous" behavior of amorphous semiconductors, which show the same characteristic "long tails" of resource depletion. Both these behaviors require a general form of mathematical analysis. Curiously, this very simple math may also have been buried for over 50 years, as it has recently been shown to describe many commonplace situations. To catch a glimpse into the fascinating world of mathematical authority and consensus where momentum and sunk costs seem to trump scientific understanding, read this post:
http://mobjectivist.blogspot.com/2009/06/dispersive-transport.html
I think that to a great many people PO is considered fringe. My personal theory is that it is fringe because there is no theory, only heuristics based on empirical evidence. Anything that strikes someone as "anomalous" will not hold the same convincing argument unless it can be proven via some physical model. That never did exist for PO, only heuristic models.

The observation occurred in the same late 1950's time-frame as Hubbert. The seemingly anomalous observation in solid-state physics took years to understand and IMO still hadn't been thoroughly proven. The actual model is remarkably simple and shows some potentially valuable generality.