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Thursday, 2020 April 23, 06:43 — medicine, politics

I’ll sit this one out

Looks like I’m staying home alone until a vaccine comes; it’s what I mostly do anyway, though I miss the occasional card game. As a libertarian, I do not presume to know what’s best for others. So, lucky me, I need not obsess about policy.

Sunday, 2020 April 19, 14:52 — cartoons

early webcomics gallery

Joe Average’s first anniversary strip features characters from 37 other strips. Can you help me name them? Some have fallen off the Web.

Nukees S.S.D.D Look What I Brought Home (?) Superosity
Road Waffles ? Life at Bayside (?) Bobbins
Krazy Larry Ashfield When I Grow Up
Bruno the Bandit Avalon High Joe Average
? Soap on a Rope (?) Melonpool
? ? It’s Walky
Awkward Zombie (?) ? ?
Help Desk Clan of the Cats GPF
Sinfest ? ?
Everything Jake Real Life ?
Alice Funny Farm The Class Menagerie
? Suburban Jungle ?
Monday, 2020 March 30, 10:35 — curve-fitting

Scribbles: The Ensmoothening, Part III

Many of the curves in this chart have some unsightly wiggles. That’s because, when a function of degree 2 or higher tries to approximate a piecewise constant, it tends to go back and forth across the target. So here instead I fitted each such function not to the piecewise constant directly but to the fit of the next lower degree.
( . . more . . )

Wednesday, 2020 March 11, 02:07 — merch

supply issues

I’ve had a number of mugs printed by Zazzle, and most of them came out gorgeous; but last summer I was peeved enough by a delivery cock-up to want to take my business elsewhere. Recently I got around to doing something about it, with even more disappointing results.

Threadless would not let me sign up. I can’t tell which of my address, handle and password offends it, let alone how.

Cafepress failed to upload my design.

Spreadshirt and CustomInk cannot do a wraparound design on a mug.

Who else is out there? Maybe I have cooled off enough to go back to Zazzle.

Monday, 2020 March 9, 20:18 — spam

pull the other one

This week I’ve had a flood of mail with titles like VIDEO OF YOU! and YOU GOT RECORDED!. A tweetmate asked me to save and share one, so here it is. ( . . more . . )

Wednesday, 2020 February 12, 16:57 — prose

a sense of place?

I read Jack Vance’s memoir, of which many pages say “We went to Ireland / Tahiti / Kashmir . . . found a pleasant cottage and stayed there for a couple of months, cranking out stories.” It would be pleasant to know what was written where! Perhaps Jack himself did not remember. But it is impossible not to imagine that “The Moon Moth” was conceived on the houseboat in Kashmir.

Thursday, 2019 November 28, 19:51 — mathematics

it’s in the literature

On a truncated icosahedron / buckyball / Telstar-style soccer ball, consider two adjacent hexagons and the two pentagons that are adjacent to both. These four faces can be removed, rotated by a right angle, and reattached, causing only a small change to the overall shape. Most fullerenes have at least one such patch.

If I ever get around to making more printable models of fullerenes, I would omit those that can be changed, by the above twist, into one of higher symmetry. I have a pretty good idea of how I’d go about listing the fullerenes and finding their siblings; but I do not have a grip on distinguishing symmetry groups of the same order – e.g., that of the regular tetrahedron versus that of a hexagonal prism – and a subgroup of one may not be a subgroup of the other.

So I got out An Atlas of Fullerenes in the hope of understanding how they did it – and happened to open to a chapter I had not looked at before, which covers the Stone-Wales transformation (for so it is named) and lists, up to C50 (15 hexagons), which fullerenes change with which.

The 812 smallest fullerenes are thus cut to 72 in 47 families. The biggest of these families has six remaining members, four with C2v symmetry (one axis of twofold rotation, and a reflection plane containing that axis) and two with C3 symmetry (chiral with one threefold axis). Their symmetry numbers are 4 and 3 respectively, but as C3 is not a subgroup of C2v I keep them all.

Surprisingly the ten families of C50 include two with no nontrivial symmetry at all.

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