15 July 2015

A New Paradigm for Control

Some quotes from https://www.quantamagazine.org/20150714-explosive-percolation-networks/ - just replace "D'Souza" or "one" or "we" with "Government" and you might see why I find this article disturbing (my emphasis).

D’Souza wants to learn how to better control complex networks. Connectivity is a double-edged sword, according to her. “For normal operating systems [like the Internet, airline networks or the stock exchange], we want them to be heavily connected,” she said. “But when we think about epidemics spreading, we want to curtail the extent of the connectivity.” Even when high connectivity is desirable, it can sometimes backfire, causing a potentially catastrophic collapse of the system. “We’d like to be able to intervene in the system easily to enhance or delay its connectivity,” depending on the situation, she said.

Explosive percolation is a first step in thinking about control, according to D’Souza, because it provides a means of manipulating the onset of long-range connectivity via small-scale interactions. A series of small-scale interventions can have dramatic consequences — for good or ill.

Public relations professionals often ask how D’Souza’s work might help their products go viral. She typically responds by pointing out that her models actually suppress viral behavior, at least in the short term. “Do you want to eke out all the gains as quickly as you can, or do you want to suppress [growth] so when it does happen, more people learn about it right away?” she said.

In other systems, such as financial markets or electrical power grids, when a collapse occurs, it is likely to be catastrophic, and this patchwork approach could be used to reverse the process, breaking up the über-connected system into a collection of disjointed clusters, or “islands,” to avoid catastrophic cascading failures. Ideally, one would hope to find a “sweet spot” for the optimal level of intervention.

The next step is to identify signs that may indicate when a system is about to go critical. Researchers understand phase transitions like the ones that happen when water turns to ice, and can identify signs of an impending change. The same cannot be said for explosive percolation. “Once we have a better understanding, we’ll be able to see how our control interventions are impacting the system,” D’Souza said. “We will have this data we can analyze in real time to see if we are seeing the signature of the early warning signals from many different classes of transitions.”

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