1. The problem is to simplify the expression surd 2 divided by 2 tau, which can be written as $\frac{\sqrt{2}}{2\tau}$. 2. Recall that $\tau$ is a constant equal to $2\pi$. So the expression becomes $\frac{\sqrt{2}}{2 \times 2\pi} = \frac{\sqrt{2}}{4\pi}$. 3. There are no common factors to cancel between numerator and denominator, so the expression is already in simplest form. 4. Therefore, the simplified expression is $$\frac{\sqrt{2}}{4\pi}$$.