Taiji is True North?

Ever wonder why we face certain directions in taiji practice?
One might argue that it's because "taiji" can refer to the Pole Star, or because the Chinese emperors faced south, or because of the placement of a courtyard used for practice, but the real reason might be in our bodies.
A recent study in the Proceedings of the National Academy of Sciences "Direct observations of roe deer revealed that animals orient their heads northward when grazing or resting. Amazingly, this ubiquitous phenomenon does not seem to have been noticed by herdsmen, ranchers, or hunters. Because wind and light conditions could be excluded as a common denominator determining the body axis orientation, magnetic alignment is the most parsimonious explanation. To test the hypothesis that cattle orient their body axes along the field lines of the Earth's magnetic field, we analyzed the body orientation of cattle from localities with high magnetic declination. Here, magnetic north was a better predictor than geographic north."

{Picture} Rob Taverner in the UK practicing taiji in front of his herd. Metro.co.uk