He says an extreme solar storm could fire a catastrophic electromagnetic pulse at Earth, crash the power grid, and thereby trigger anarchy.

A femtosecond laser pulse lasts on the order of a quadrillionth of a second but reaches a peak power equivalent to that of the entire power grid of North America during its short burst.

This is used to assess the accuracy of the Gaussian approximation commonly used in the performance analysis of UWB impulse radio networks.