mildly mathematical: sometimes an X is not an X.

a colleague of mine shared this link earlier, and i think it's worth passing along. though this video is 4min long, be warned:

once you reach the main TED website,
there might be no coming back for a while,
as there are so many fine talks to hear ..

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Terry Moore: Why is 'x' the unknown? (a TED talk)

Why is 'x' the symbol for an unknown? In this short and funny talk, Terry Moore gives the surprising answer.

Terry Moore is the director of the Radius Foundation, a forum for exploring and gaining insight from different worldviews.

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in other news, i'm still embedded in re-writing this preprint. there's light at the end of the tunnel .. but it's still slow going.