  Maximizing the speed and precision of communication while minimizing power
dissipation is a fundamental engineering design goal. Also, biological systems
achieve remarkable speed, precision and power efficiency using poorly
understood physical design principles. Powerful theories like information
theory and thermodynamics do not provide general limits on power, precision and
speed. Here we go beyond these classical theories to prove that the product of
precision and speed is universally bounded by power dissipation in any physical
communication channel whose dynamics is faster than that of the signal.
Moreover, our derivation involves a novel connection between friction and
information geometry. These results may yield insight into both the engineering
design of communication devices and the structure and function of biological
signaling systems.
