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Lepus californicus
jackrabbit, this afternoon.
Around 30 years ago, a friend got a gig interpreting for a Japanese writer who'd come to the USA to interview William S. Burroughs. My friend told Burroughs he'd always liked the author's idiosyncratic use of the phrase "subject to", e.g. (from Junky):
Junkies run on junk time and junk metabolism. They are subject to junk climate. They are warmed and chilled by junk.
Burroughs gave my friend a photo signed with a note that he worked "subject to" into.

Seeing this sign today reminded me of Burroughs: actual sign It makes me wish it were a trend, with "subject to" appearing in signs where it's normally implicit, e.g.: reworked sign
An equilateral triangle inscribed in a circle of diameter d has sides of length sin(60°) × d. An inscribed square's sides have length sin(45°) × d. A regular pentagon's sides have length sin(36°) × d. Generally: sides of an inscribed regular n‑gon have length sin(180°÷n) × d.

For some values of n, sin(180°÷n) can be expressed algebraically, in particular with just the operations +, -, ×, ÷, √.  sin(60°) = √3÷2;  sin(45°) = √2÷2;  sin(36°) = √((5‑√5)÷8). The heptagon is the first regular polygon whose side length cannot be expressed algebraically; sin(180°÷7) is a transcendental number.

The only algebraic values of sin(180°÷n) that Euclid was aware of had values of n with prime factors from the set {2,3,5}. No progress was made on finding other examples until 1796, when Gauss showed that sin(180°÷17) is algebraic. This result applies to more than just the construction of regular 17‑gons; it leads to important topics in number theory.

I am continually struck by the difference between skill required to understand mathematical operations and to devise them. A demonstration that sin(180°÷17) is algebraic doesn't require more than high school math to follow but it eluded mathematicians for two millenia.

Not that math is the only thing that's harder to create than to appreciate, as I am reminded of any time I try to write a short story.
Yucca brevifolia
We had an ice storm.
Something went wrong with my left eye starting on December 31. Flashes of light around the edges of the visual field, and a barrage of new floaters the next day. The web told me these are symptoms of posterior vitreous detachment, in most cases no big deal but get it examined right away to make sure the retina isn't torn as well. Right away in this case came on January 3, the first day I could find an eye doctor's office open. How cool of my eye to pick Saturday of a holiday weekend to disintegrate.

Eye doctors have the best equipment. Their waiting rooms are always full, because who wouldn't want to rest their head on a fine Swiss microscope.

If only all age-related deterioration were this benign. My eye is OK, no treatment is needed. I've got more floaters but they're more entertaining than annoying. They come and go and usually aren't obtrusive. I'd show you, but my visual cortex doesn't have a print screen button. It's like a snow dome except with cooler shapes that aren't as numerous nor as opaque.