The US electrical grid is still on the verge of collapse a full decade after the 2003 blackout that thrust 50 million Americans into the dark during the heat of summer.
Or at least that's the conclusion of a mathematical analysis of the electrical grid that was published in the science journal Nature Physics on Sunday. The Israeli and US team said the networks are dependent on certain critical nodes.
If one of these small but critical points fail, then the entire system is vulnerable to a sudden collapse as a result of a cascade of errors.
It seems like a reasonable enough argument.
Earlier this month, Nature asked whether or not the US electrical grid is hardened against outages like the 2003 blackout that slammed the northeast for two days -- causing $10 billion in economic losses.
And it was indeed a cascade of errors that brought down the system. A power company in Ohio got sloppy about trimming the trees around the lines. So a power line tripped in Ohio. A software error meant that the power company didn't notice.
The lines heated up and apparently sagged, contacting more trees. A second power line tripped.
And then a third.
Within hours, the cascade had escaped Ohio to blackout much of the American northeast.
And it was all started by so-called poor vegetation management -- that is, the power company failed to trim some trees.
But lots of power companies everywhere fall behind in their tree-trimming. Heck, power lines are brought down by trees every single day without triggering a collapse of major portions of the US electrical grid.
If small failures frequently led to big collapses, we'd be in real trouble.
But major blackouts are rare. The fact that we're looking back a decade to 2003 might tell us how rare.
Electrical engineer Jeff Dagle told Scientific American that he wasn't convinced by the new study. "[T]his doesn't reflect the physics of how the power grid operates," he said.
In the real world, major power outages aren't usually a matter of small goof cascading into a general collapse.
Every blackout since 2003 except one has been caused by a massive assault on multiple points of the US electrical grid -- usually as a result of supersized hurricanes like 2005's Hurricane Katrina or 2012's Hurricane Sandy.