Tuesday, January 23, 2007

Evil, bad, diseased, or just ugly?

"Evil" is a word rarely heard in scientific discourse, at least among physicists, whose subject of study is after all morally neutral for pretty much any sensible definition of "morally". "Bad", "diseased" or "ugly" might be heard occasionally. But having all of them applied to a topic as relatively arcane as the fourth-root prescription for staggered fermions is, well, staggering. At last year's lattice meeting there was a lot of discussion as to whether this prescription was diseased or merely ugly. Now Mike Creutz has taken the discussion from the medicinally-aesthetic to the moral level by suggesting that rooting is actually evil. The arguments are much the same as before: The rooted staggered theory has a complicated non-locality structure at non-vanishing lattice spacing, and there is no complete proof (although there are strong arguments that many find very convincing) that this non-locality goes away in the continuum level. The debate will no doubt simmer on until a fully conclusive proof either way is found; the question is only, what kinds of unusual title words are we still going to see?