Diner cry after a bell is rung / THU 5-5-22 / Student-led LGBTQ+ grp / Terence ___ noted expert on combinatorics and analytic number theory / Colvin civil rights pioneer who refused to give up her seat on a segregated bus nine months before Rosa Parks / Like some horse bedding

Constructor: Adam Wagner

Relative difficulty: Easy (Challenging for me because I am uniquely stupid)

THEME: [FIBONACCI] / SEQUENCE (37D: When preceded by [the circled letters], progression starting with 0 and 1) + [FIBONACCI] / SPIRAL (30A: When preceded by [the circled letters], natural shape said to be seen in 61-Across and 27-Down) — black squares are supposed to evoke a FIBONACCI SPIRAL (I think) and while at first I thought the circled squares were also supposed to evoke that spiral, I think those boxes simply contain the numbers (excluding the initial "0" and "1") that start the FIBONACCI SEQUENCE (i.e. [0], [1], 1, 2, 3, 5, 8, 13, 21, 34, 55,  [89], [144], etc.)

Theme answers:

• GOLDEN RATIO (11D: Numerical constant associated with [the circled letters])
• SUNFLOWERS (61A: Classic van Gogh subject)
• NAUTILI (27D: Certain cephalopods)
• MATH TEACHER (17A: Someone well versed in this puzzle's theme)

Word of the Day: FIBONACCI SEQUENCE —

In mathematics, the Fibonacci numbers, commonly denoted F_n, form a sequence, the Fibonacci sequence, in which each number is the sum of the two preceding ones. The sequence commonly starts from 0 and 1, although some authors omit the initial terms and start the sequence from 1 and 1 or from 1 and 2. Starting from 0 and 1, the next few values in the sequence are:

0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, ...

The Fibonacci numbers were first described in Indian mathematics, as early as 200 BC in work by Pingala on enumerating possible patterns of Sanskrit poetry formed from syllables of two lengths. They are named after the Italian mathematician Leonardo of Pisa, later known as Fibonacci, who introduced the sequence to Western European mathematics in his 1202 book Liber Abaci.

Fibonacci numbers appear unexpectedly often in mathematics, so much so that there is an entire journal dedicated to their study, the Fibonacci Quarterly. Applications of Fibonacci numbers include computer algorithms such as the Fibonacci search technique and the Fibonacci heap data structure, and graphs called Fibonacci cubes used for interconnecting parallel and distributed systems. They also appear in biological settings, such as branching in trees, the arrangement of leaves on a stem, the fruit sprouts of a pineapple, the flowering of an artichoke, an uncurling fern, and the arrangement of a pine cone's bracts.

Fibonacci numbers are strongly related to the golden ratio: Binet's formula expresses the nth Fibonacci number in terms of n and the golden ratio, and implies that the ratio of two consecutive Fibonacci numbers tends to the golden ratio as n increases. Fibonacci numbers are also closely related to Lucas numbers, which obey the same recurrence relation and with the Fibonacci numbers form a complementary pair of Lucas sequences. (wikipedia)

• • •

When I finally saw that those circled squares were gonna spell FIBONACCI, I thought "oh, we're doing this (again), are we?" I've definitely seen mathy constructors try to do something with this sequence before. I was not prepared for how hard the puzzle would be even after I figured out the basic premise (and filled out the circled squares). From the cross-referenced 1-Across, which meant that, well, I couldn't get 1-Across for a while, which meant I couldn't see "FIBONACCI" for a while ... to KORUNAS, which, dear lord, ouch, that is not a foreign currency I've ever seen in my puzzle or anywhere else in my life (4A: Units on Czech checks) ... to, well, so many things in the spiral part of the grid, including HINT, SECT, TOQUE, CLAUDETTE, DOLLIES (I had PALLETS), SLIT, SPOT, ORDER UP, NAUTILI (the plural!) ... I had to go the very heart of the spiral and work my way back out. The spiral part is so horrifically cut off from the rest of the grid (you can access it only via the narrowest of SLITs—the "E" at CLEESE/ETSY) that the spiral became a version of the thing I hate in highly segmented hard puzzles, which is to say a claustrophobic dead end. In the end, I just don't think the execution works here. That is, the black squares only kinda sorta evoke the SPIRAL they claim to evoke, and the circled squares ... wow, I really really really wanted to make them into a spiral. The puzzle seemed to want me to. SPIRAL, it said. I know it also said SEQUENCE, but I figured the SPIRAL was the SEQUENCE. So I tried connecting the letters, thusly:

... and then thusly:

... before finally realizing that while those letters spelled FIBONACCI, they didn't form a visual pattern; instead, they just appeared in the numbers associated with the FIBONACCI / SEQUENCE. The effect of it all, for me, was clunky and awkward. The puzzle is trying to do So Much, including cram in bonus theme answers, that the fill starts to buckle and the premise just doesn't quite come off, visually. It's kind of smugly in-group-y too, what with the TAO clue (42A: Terence ___, noted expert on combinatorics and analytic number theory), and then the MATH TEACHER answer, particularly the way that it's clued (17A: Someone well versed in this puzzle's theme). It's presumptuous. Are MATH TEACHERs well versed in it? All of them? I took math classes from many MATH TEACHERs until the age of 19 or so, and it's not like FIBONACCI came up a lot. Mostly never. I've heard about it way more in my puzzle-solving life than I ever did in math class. Is SCIENCE CAMP also supposed to be a themer? Like, people who went to SCIENCE CAMP will like this? I don't know. I like the unusual shape of the grid, and I was happy to learn CLAUDETTE (more people should be named CLAUDETTE), but the elaborate architectural stuff going on here just felt forced to me, and the joy of solving largely dropped out, though much of the joy drain came from foreign currency (KORUNAS) and (once again) laugh syllables (HAR) and EXCOPS (I see too many fascist "Blue Lives" flags on a daily basis to get any great pleasure from seeing COPS in my puzzle, ex- or otherwise) (33D: Many security guards), and finally STRAWY, which, as you can see in the posted grid, I refused to write in, even at the bitter end. I wrote in STRAW- and just ... no. Sometimes you have to take a stand against nonsense (45D: Like some horse bedding).

Is GSA "Gay Student Association"? Whoa, no, it's "Gender-Sexuality Alliance" and this is the very first I'm hearing of it despite working on a college campus for my entire life it seems. Did all of you know what those letters stood for? Weird to drop a newish initialism on people where there's no real way to determine what the letters stand for without guessing. It's an interesting initialism, way more interesting than General Services Administration (the typical GSA clue), but hard to infer the "G" and "S" even with context. Maybe the fact that "gay" and "student" were in the clue supposed to tell us "that's not what the G and S stand for," but still, I'd've been guessing. Looks like GSA can also be "Gay-Straight Alliance" ... just to make matters more confusing for ya.  COOL DUDE and ["Cat"] don't seem like equivalents. That is, coolness is not inherent in catness, which is why you can call someone a "cool cat" without its being absurdly redundant. Don't get me wrong, I really like the "COOL DUDE / REX" SEQUENCE, but ["Cat"] just seems like an off clue there. 

If you are a math person who really gets off on things in your wheelhouse, and this floated your boat, fantastic. I just couldn't groove on the wave it was laying down, man. (sorry, don't know what kind of -speak that is...). See you tomorrow.

Signed, Rex Parker, King of CrossWorld

[Follow Rex Parker on Twitter and Facebook]