Jordana Cepelewicz in Nautilus:
It is 7 o’clock in the morning and Harvey Friedman has just sent an email to an unspecified number of recipients with the subject line “stop what you are doing.” It features a YouTube link to a live 1951 broadcast of a concert by the famous Russian pianist Vladimir Horowitz. “There is a pattern on YouTube of priceless gems getting taken down by copyright claims,” Friedman writes, “so I demand (smile) that you stop everything you are doing, including breathing, eating, thinking, sleeping, and so forth, to listen to this before it disappears.”
His comment takes its place at the top of a chain of emails stretching back months, with roughly as many messages sent at 3 a.m. as at noon or 9 p.m. The haphazard correspondence covers a wide range of topics, from electronic music editing to an interdisciplinary field Friedman calls “ChessMath.” At one point, he proposes to record at home, by himself, a three-part “Emotion Concert.” Anonymous piano players on the email thread discuss their own thoughts on the lineup.
As diverse as the topics in the email history are, Friedman asks the same question of them all: What are their basic constituents and what laws govern them? He seems to be searching for the right vocabulary—“the right way,” he says, “of talking about what the fundamental ideas are, to black-box the ad hoc technicalities and get to the real meat of the thing.”
That is not to say all of these topics are equal. There is one that is nearest and dearest to Friedman’s heart: the foundations of mathematics, which concerns itself with the consistency, unity, and structure of mathematics itself.