The thermodynamics of the hurricane—Nature’s steam engine—presents surprising contrasts with that of the steam locomotive. The hurricane rejects not only its waste heat at the lowest available temperature (as all heat engines must do to maximize efficiency), but also its work (that is, the kinetic energy of its winds) via frictional dissipation at the highest available temperature. We show how the hurricane’s “super-Carnot” efficiency is consistent with the laws of thermodynamics. We also show that even standard heat engines can achieve “super-Carnot” efficiency, albeit via a different mechanism and to a far inferior degree than the hurricane.

We employ the energy-time uncertainty principle to provide heuristic yet helpful insights into tunneling, Unruh radiation, the Schwinger effect, and the ground state of the electromagnetic field. The position-momentum uncertainty principle is employed in auxiliary roles. We also discuss the similarities and differences between quantum and thermal fluctuations.

A charged parallel-plate vacuum capacitor moves uniformly through an inertial frame. Its field energy alone does not transform according to the familiar law ‘‘energy=γ× rest energy.’’ However, when the stresses in the supports are taken into account, the entire system does satisfy this relation.

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