I am totally convinced we should abandon the π religion in favor of the τ religion, but there is a very unfortunate choice of symbols that stands in the way of enlightenment:<p>A visual inspection immediately proves that pi (the Greek symbol π) is equal to two taus (π = ττ) rather than the other way around (τ != ππ).<p>One way out of this quagmire is to rename pi as tau and tau as pi? This way we can also appropriate pi-day as tau-day and most people will not know the difference.