That&#x27;s the same guy that posts as @graycat here on HN. Most of his posts espouse the wonders of hardcore applied math, often with a comprehensive bibliography, so he seems to know what he&#x27;s talking about, although his rambling (and, to be fair, somewhat off-topic) style does him no favors on HN, which is why his posts almost always end up at the bottom of the comments here (see also @michaelochurch).