For et par dage siden anbefalede Zach Wissner-Gross fra Fiddler on the Proof langnovellen “Understudies” af #GregEgan, og nu har jeg fået den læst. Wow! For fans af fiddler-opgaver og den slags, så er det her en gave. Og lad mig med det samme indrømme, jeg løste altså ikke alle opgaverne i teksten, mens jeg læste. De er svære!

Fiddler on the Proof “Understudies”

Specielt en af opgaverne fangede mig, fordi jeg ikke helt kunne forstå løsningen. Så i det her indlæg vil jeg prøve at læse opgave og løsning, indtil jeg forstår det.

“A few years before the fall of the Berlin Wall,” she said, “an English journalist was imprisoned in East Germany. She was able to exchange letters with her husband, but they knew their mail was being read by authorities. Among the first things her husband sent her was a computer printout of a poem, written by their twelve-year-old daughter, which the journalist kept pinned to the wall of her prison cell. It read:

“Evening light fades / Quiet descends / The joking boy relaxed / Sweetly amazed / Night promises peaceful dreams / Until morning.

“Historians studying the correspondence between the couple found that the words of this poem showed up in their letters far more often than would have been expected, and so might have played a part in a code they used.

“Once, in response to a letter where her husband used ‘joking,’ ‘descends,’ ‘quiet,’ ‘fades,’ and ‘light,’ in that order, the journalist responded by using ‘evening,’ ‘amazed,’ ‘boy’ three times, ‘amazed,’ ‘evening,’ ‘joking’ twice, ‘relaxed,’ ‘sweetly,’ ‘amazed,’ ‘sweetly,’ then ‘relaxed.’

“What was she communicating?”

Og den korrekte løsning:

“The husband wasn’t saying anything in his letter,” she explained. “He was providing a key that the journalist could use to help encode her own message. She took his numbers—five, four, three, two, one, by their position in the poem, with ‘evening’ as zero and ‘the’ omitted—then used the dot matrix printout of the poem, with each letter of the alphabet forming a grid five dots wide, to transform them into a number for each row, adding up those with a matching dot, leaving out the rest. The lowercase letters ‘o’ and ‘k’ provided her response. She was saying ‘okay.’ ”

Lad os tage den igen, langsomt.

Digtet kan også skrives således:

0	Evening	4	descends	8	Sweetly	12	peaceful
1	light	5	joking	9	amazed	13	dreams
2	fades	6	boy	10	Night	14	Until
3	Quiet	7	relaxed	11	promises	15	morning

Det første brev:

“a letter where her husband used ‘joking,’ ‘descends,’ ‘quiet,’ ‘fades,’ and ‘light,’ in that order, …’ ”

Det bliver altså til 5, 4, 3, 2 og 1.

Og det andet brev:

“… the journalist responded by using ‘evening,’ ‘amazed,’ ‘boy’ three times, ‘amazed,’ ‘evening,’ ‘joking’ twice, ‘relaxed,’ ‘sweetly,’ ‘amazed,’ ‘sweetly,’ then ‘relaxed.’ ”

Dette svarer til 0, 9, 6, 6, 6, 9, 0, 5, 5, 7, 8, 9, 8, 7.

Jeg kan se, at der er noget struktur her, der passer med o og k. I første omgang med et tilfældigt bud på en font.

     x
 xx  x
x  x x  x
x  x x x
x  x xx
 xx  x x
     x  x

Eller:

0         5 x
9  xx     5 x
6 x  x    7 x  x
6 x  x    8 x x
6 x  x    9 xx
9  xx     8 x x
0         7 x  x

Ja, noget her fungerer. Samme linje af pixler i det samme bogstav giver det samme tal.

Men jeg har ikke brugt 5, 4, 3, 2, 1 til det her? Hov, jeg prøver lige igen, med en bedre font.

0          5 x
9  xxx     5 x
6 x   x    7 x  x
6 x   x    8 x x
6 x   x    9 xx
9  xxx     8 x x
0          7 x  x

Ja, nu virker det.

“_xxx_” bliver parret sammen med “54321”. Det giver “04320”. Og tværsummen af det er 9. Og således bliver toppen af o’et til 9. “x___x” bliver til “50001”, bliver til 6. Osv.

Jeg tror, jeg forstår den!