If you find your­self grap­pling with an intel­lec­tu­al prob­lem that’s gone unsolved for mil­len­nia, try tak­ing a few months off and spend­ing them on activ­i­ties like swim­ming and med­i­tat­ing. That very strat­e­gy worked for a Cam­bridge PhD stu­dent named Rishi Rajpopat, who, after a sum­mer of non-research-relat­ed activ­i­ties, returned to a text by the ancient gram­mar­i­an, logi­cian, and “father of lin­guis­tics” Pāṇi­ni and found it new­ly com­pre­hen­si­ble. The rules of its com­po­si­tion had stumped schol­ars for 2,500 years, but, as Rajpopat tells it in an arti­cle by Tom Almeroth-Williams at Cam­bridge’s web­site, “With­in min­utes, as I turned the pages, these pat­terns start­ed emerg­ing, and it all start­ed to make sense.”

Pāṇi­ni com­posed his texts using a kind of algo­rithm: “Feed in the base and suf­fix of a word and it should turn them into gram­mat­i­cal­ly cor­rect words and sen­tences through a step-by-step process,” writes Almeroth-Williams. But “often, two or more of Pāṇini’s rules are simul­ta­ne­ous­ly applic­a­ble at the same step, leav­ing schol­ars to ago­nize over which one to choose.” Or such was the case, at least, before Rajpopat’s dis­cov­ery that the dif­fi­cult-to-inter­pret “metarule” meant to apply to such cas­es dic­tates that “between rules applic­a­ble to the left and right sides of a word respec­tive­ly, Pāṇi­ni want­ed us to choose the rule applic­a­ble to the right side.”

That may not be imme­di­ate­ly under­stand­able to those unfa­mil­iar with the struc­ture of San­skrit. Almeroth-Williams’ piece clar­i­fies with an exam­ple using  mantra, one word from the lan­guage that every­body knows. “In the sen­tence ‘devāḥ prasan­nāḥ mantraiḥ’ (‘The Gods [devāḥ] are pleased [prasan­nāḥ] by the mantras [mantraiḥ]’) we encounter ‘rule con­flict’ when deriv­ing mantraiḥ, ‘by the mantras,’ ” he writes. ” The deriva­tion starts with ‘mantra + bhis.’ One rule is applic­a­ble to the left part ‘mantra’ and the oth­er to right part ‘bhis.’ We must pick the rule applic­a­ble to the right part ‘bhis,’ which gives us the cor­rect form ‘mantraih.’ ”

Apply­ing this rule ren­ders inter­pre­ta­tions of Pāṇini’s work almost com­plete­ly unam­bigu­ous and gram­mat­i­cal. It could even be employed, Rajpopat has not­ed, to teach San­skrit gram­mar to com­put­ers being pro­grammed for nat­ur­al lan­guage pro­cess­ing. It no doubt took him a great deal of inten­sive study to reach the point where he was able to dis­cov­er the true mean­ing of Pāṇini’s clar­i­fy­ing metarule, but it did­n’t tru­ly present itself until he let his uncon­scious mind take a crack at it. As we’ve said here on Open Cul­ture before, there are good rea­sons we do our best think­ing while doing things like walk­ing or tak­ing a show­er, a phe­nom­e­non that philoso­phers have broad­ly rec­og­nized through the ages — and, like as not, was under­stood by the great Pāṇi­ni him­self.

Relat­ed con­tent:

Learn Latin, Old Eng­lish, San­skrit, Clas­si­cal Greek & Oth­er Ancient Lan­guages in 10 Lessons

Intro­duc­tion to Indi­an Phi­los­o­phy: A Free Online Course

Can Arti­fi­cial Intel­li­gence Deci­pher Lost Lan­guages? Researchers Attempt to Decode 3500-Year-Old Ancient Lan­guages

Why Algo­rithms Are Called Algo­rithms, and How It All Goes Back to the Medieval Per­sian Math­e­mati­cian Muham­mad al-Khwariz­mi

How Schol­ars Final­ly Deci­phered Lin­ear B, the Old­est Pre­served Form of Ancient Greek Writ­ing

Has the Voyn­ich Man­u­script Final­ly Been Decod­ed?: Researchers Claim That the Mys­te­ri­ous Text Was Writ­ten in Pho­net­ic Old Turk­ish

Based in Seoul, Col­in Marshall writes and broad­casts on cities, lan­guage, and cul­ture. His projects include the Sub­stack newslet­ter Books on Cities and the book The State­less City: a Walk through 21st-Cen­tu­ry Los Ange­les. Fol­low him on Twit­ter at @colinmarshall or on Face­book.

Read a nov­el by Charles Dick­ens, and you’ll still today feel trans­port­ed back to the Lon­don of the eigh­teen-twen­ties. Some of that expe­ri­ence owes to his lav­ish­ly repor­to­r­i­al descrip­tive skills, but even more to his way with dia­logue. Dick­ens faith­ful­ly cap­tured the vocab­u­lary of the times and places in which he set his sto­ries, and for some par­tic­u­lar­ly col­or­ful char­ac­ters, went as far as to ren­der their dis­tinc­tive accents pho­net­i­cal­ly: that of The Pick­wick Papers’ beloved valet Sam Weller, for instance, with its swap­ping of “v” and “w” sounds that briefly over­took the East End. But it’s one thing to read the voice of a Lon­don­er of that time, and quite anoth­er to hear it.

No audio record­ings exist of Dick­en­sian Lon­don, of course, but we have the next-best thing in the video above from Youtu­ber Simon Rop­er — and specif­i­cal­ly the sec­tion that begins at about 11:30, when he per­forms the accent of a Lon­don­er in the year 1826. Most every­thing he says should sound quite intel­li­gi­ble to any Eng­lish-speak­er today, though few, if any, will ever have encoun­tered some­one who speaks in quite the same way in real life.

In this era, Rop­er adds in the onscreen notes, “you can hear the start of glot­tal rein­force­ment, where a glot­tal stop is insert­ed between a vow­el and a plo­sive con­so­nant at the end of a word.” What’s more, “non-rhotic­i­ty (r‑loss in most posi­tions) has caused vow­els that were orig­i­nal­ly fol­lowed by ‘r’ to become cen­ter­ing diph­thongs.”

Seri­ous stuff, for a man who describes him­self as “not a lin­guist.” Nev­er­the­less, Rop­er has in this video assem­bled an impres­sive tour of Lon­don accents over 660 years, with “twelve record­ings, all of men with sus­pi­cious­ly sim­i­lar voic­es, and each one is set 60 years after the last one, and each one is the grand­son of the pre­vi­ous one.” (When the video went viral, the New States­man pro­filed him for his achieve­ment.) The ear­li­est, set in 1346, will sound more famil­iar in cadence than in con­tent, at least to those who haven’t stud­ied Mid­dle Eng­lish. Com­pre­hen­sion does­n’t become a much sim­pler mat­ter for most of us mod­erns until about 1586, but Rop­er’s accent comes to sound ver­i­ta­bly transat­lantic by 1766. Per­haps not coin­ci­den­tal­ly, that was just before the Amer­i­cans broke off deci­sive­ly from the moth­er­land to do things their own way — but also to pre­serve a few of the old ways, includ­ing ways of speech.

Relat­ed con­tent:

A Brief Tour of British & Irish Accents: 14 Ways to Speak Eng­lish in 84 Sec­onds

One Woman, 17 British Accents

Peter Sell­ers Presents The Com­plete Guide To Accents of The British Isles

A Tour of U.S. Accents: Boston­ian, Philadelph­ese, Gul­lah Cre­ole & Oth­er Intrigu­ing Dialects

Meet the Amer­i­cans Who Speak with Eliz­a­bethan Eng­lish Accents: An Intro­duc­tion to the “Hoi Toi­ders” from Ocra­coke, North Car­oli­na

Based in Seoul, Col­in Marshall writes and broad­casts on cities, lan­guage, and cul­ture. His projects include the Sub­stack newslet­ter Books on Cities and the book The State­less City: a Walk through 21st-Cen­tu­ry Los Ange­les. Fol­low him on Twit­ter at @colinmarshall or on Face­book.