Velocity of sheep in a vacuum

The theoretical maximum velocity of a sheep in a vacuum is expressed in sheepsecs (Ssx), calculated as follows:

Speed of light (c) divided by wooldrag (Wd) + Welshmen (Wm), where wooldrag is a species-defined drag coefficient determined by the length and pliability of the fleece and Welshmen is the number of locals who have turned up in their wellies, and are hanging on for dear life.

Wooldrags have recently been calculated by researchers at CERN, and the latest experiments shed some light on the phenomenon, but it is still mysterious. The effect is similar to friction here on Earth, but is due to the interaction of the wool and fluctuations in the quantum vacuum. Researchers have applied to the EU for further funding, but it has been put on hold as a result of the recent outbreak of foot and mouth disease.