09 Feb 2014 No Comments

## Just How Much Data Can We Stuff Through an Optical Fibre?

This question on Physics Stack Exchange asks what the theoretical bandwidth of an optical fibre is. Let’s explore this question. The short answer is that a good order of magnitude rule of thumb for the maximum possible bandwidth of an optical fibre channel is about 1 petabit per second per optical mode for up to […]

14 Feb 2014 No Comments

## How is the Information in a Continuous Variable Limited?

A question on Physics Stack Exchange speculates that the information content of a human brain is infinite, because the brain’s state is described by a continuous quantum state, a “wavefunction”. As pithily answered by Emilio Pisanty, the Hilbert space of quantum mechanics, i.e. $\mathbb{L}^2(\mathbb{R}^N)$ is separable, which means we have a countably infinite number of basis […]

by Rod Vance in Physics, Thermodynamics and Information Theory Tags: Shannon Capacity Theorem, Shannon-Hartlee Theorem