Yiddish is a familiar presence in contemporary English speech. Many people use or at least know the meaning of words like chutzpah (audacity), schlep (drag) or nosh (snack).

These words have been absorbed into English from their original speakers, eastern European Jews who migrated to Britain in the late 19th century, through generations of living in close proximity in areas like London’s East End.

Linguistics scholars have even theorised that elements of a Yiddish accent may have influenced the cockney accent as it evolved in the early 20th century. Phonetic analysis of cockney speakers recorded in the mid-20th century suggests that East Enders who grew up with Jewish neighbours spoke English with speech rhythms typical of Yiddish.

A distinctive pronunciation of the “r” sound is thought to have originated among Jewish immigrants and spread into the wider population.

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But, as we explore in our new podcast, cockney reshaped the Yiddish language too. This can be seen in surviving texts from the popular culture of the Jewish immigrant East End, including newspapers and songsheets, where songs, poems and stories dramatise the thrills and challenges of modern London.

The Yiddish music of London’s East End brought together the Yiddish language and Jewish culture of eastern Europe with the raucous, irreverent style of the cockney music hall. Theatres and pubs overflowed with audiences eager to see the immigrant experience in Whitechapel represented in all its perplexity and pathos, with a good measure of slapstick comedy.

A Yiddish music hall song from around 1900 jokes that East Enders live on “poteytes un gefrayte fish” – a Yiddish version of the cockney staple fish and chips. The song lists the many novelties that immigrants encountered on arriving in the metropolis: trains running underground, women wearing trousers and people speaking on telephones.

Yiddish was also the language of street protest in the Jewish East End. During the “strike fever” of 1889, when workers throughout east London were demanding better pay and working conditions, the Whitechapel streets resonated with the voices of Jewish sweatshop workers singing:

In di gasn, tsu di masn fun badrikte felk rasn, ruft der frayhaytsgayst (In the streets, to the masses / of oppressed peoples, races / the spirit of freedom calls).

This song was penned by the socialist poet Morris Winchevsky, an immigrant from Lithuania who spoke Yiddish as a mother tongue but preferred to write in literary Hebrew. In London he switched to writing in the vernacular language of Yiddish in order to make his writing more accessible to immigrant Jewish workers. The song became a rousing anthem in labour protests across the Yiddish-speaking world, from Warsaw to Chicago.

The decline of Yiddish

Yet from the earliest days of Jewish immigration to London, the Yiddish-language culture of the East End was a focus of anxiety for the Jewish middle and upper class of the West End. They regarded Yiddish as a vulgar dialect, detrimental to the integration of Jewish immigrants in England.

While they provided significant philanthropic support for immigrants, they banned the use of Yiddish in the educational and religious institutions that they funded.

In 1883, budding novelist Israel Zangwill was disciplined by the Jews’ Free School, where he worked as a teacher, for publishing a short story liberally sprinkled with dialogues in cockney-Yiddish.

By the 1930s Yiddish had begun to decline. As Jews moved away from the East End, local Yiddish newspapers folded and publications dwindled.

The Yiddish writer I.A. Lisky, who wrote fiction for a keen but diminishing readership in the London Yiddish newspaper Di tsayt, movingly described a young woman and her grandmother who each harbour complex hopes and worries but cannot communicate: “Ken ober sibl nit redn keyn yidish un di bobe farshteyt nor a por verter english. Shvaygt sibl vayter.” (But Sybil spoke no Yiddish, and her grandmother knew only a few words of English. So she remained silent.)

Jewish writers of the postwar period were haunted by the sense of a lost connection to the Yiddish language and culture of previous generations.

The novelist Alexander Baron, who grew up in Hackney, remembered his grandparents reading Yiddish literature and newspapers, and his parents speaking Yiddish when they did not want their children to understand what they were saying.

In his novel The Lowlife (1963) the narrator’s vocabulary is peppered with Yiddish words. But these fragments are all that remains of his link to the East End where he was born. When he returns to these streets, he feels that “my too, too solid flesh in the world of the past is like a ghost of the past in the solid world of the present; it can look on but it cannot touch”.

Yiddish in London today

If you walk through the north London neighbourhood of Stamford Hill today, you’ll hear Yiddish on the streets and see new Yiddish books on the shelves of the local bookshops. Although they have no connection to the Victorian Jewish East End, the ultra-orthodox Hasidic community who live there speak Yiddish as their first language.

And for a younger generation of secular Jews, Yiddish is also acquiring a new appeal. They look to past traditions of Jewish diasporism to forge an identity rooted in language, culture and solidarity with other minorities rather than nationalism.

London is one centre of this worldwide revival: the Friends of Yiddish group established in the East End in the late 1930s is now flourishing in its contemporary incarnation as the Yiddish Open Mic Cafe. And Yiddish is once again a language that anyone can learn.

The Ot Azoy Yiddish summer school is in its 13th year, and new Yiddish language schools are thriving, including east London-based Babel’s Blessing, which teaches diaspora languages including Yiddish and offers free English classes to refugees and asylum seekers. The annual Yiddish sof-vokh hosts an immersive weekend for Yiddish learners.

Yiddish culture too is being rejuvenated. Projects we have been involved with include the Yiddish Shpilers theatre troupe, the Great Yiddish Parade marching band, which has brought Winchevsky’s socialist anthems back onto London’s streets, and the London band Katsha’nes, which has reimagined cockney Yiddish music hall songs for the 21st century.

If Yiddish was once reviled as a debased, slangy mishmash, full of borrowings and adaptations, it’s precisely for those qualities that it is celebrated today.

Nadia Valman received funding from the Arts and Humanities Research Council for research included in this article.

Vivi Lachs received funding from the Arts and Humanities Research Council for research included in this article.

Whether diving off docks, cannonballing into lakes or leaping off the high board, there’s nothing quite like the joy of jumping into water.

Olympic divers turned this natural act into a sophisticated science, with the goal of making a splash as small as possible. But another sport looks for just the opposite: the extreme maximum splash, one as high, wide and loud as possible.

Welcome to the world of “manu jumping.” Although not a familiar term in the United States, manu jumping is beloved throughout New Zealand. The sport originated in the Māori community, where popping a manu is a way of life. There, manu jumpers leap from bridges, wharves and diving platforms to make the giant splashes.

The sport is playful yet competitive. At the Z Manu World Champs, you win based on the height and width of your splash. The current record: a splash more than 32 feet high (10 meters).

The concept sounds simple, but like Olympic diving, it turns out there’s a science to manu jumping.

The Worthington splash

As fluid dynamicists, we study the way living organisms interact with fluids – for instance, how flamingos feed with their heads underwater, or how insects walk on water.

So when we stumbled upon viral videos of manu jumping on TikTok and YouTube, our curiosity was triggered. We launched a scientific investigation into the art of making a splash.

Our research was more than just fun and games. Optimizing how bodies enter fluids – whether those bodies are human, animal or mechanical – is an indispensable branch of science. Understanding the physics of water entry has implications for naval engineering, biomechanics and robotics.

We discovered that creating the perfect manu splash isn’t just about jumping into the water. Instead, it’s about mastering aerial maneuvers, timing underwater movements and knowing exactly how to hit the surface.

The microsecond the manu jumper hits the water is critical. Two splashes actually occur: The first, the crown splash, forms as the body breaks the surface. The next, the Worthington splash, is responsible for the powerful burst of water that shoots high into the air. Manu jumping is all about triggering and maximizing the Worthington splash.

So we analyzed 75 YouTube videos of manu jumps. First, we noticed the technique: Jumpers land glutes first, with legs and torso scrunched up in a V-shaped posture.

But the moment they go underwater, the divers roll back and kick out to straighten their bodies. This expands the air cavity, the space of air created in the water by the jump; then the cavity collapses, detaching itself from the body. This period of detachment is known as “pinch-off time” – when the collapse sends a jet of water shooting upward. All of this happens within a fraction of a second.

Answers from Manubot

We found that jumpers entered the water at a median V-angle of about 46 degrees. Intrigued, we recreated these movements in a lab aquarium, using 3D-printed, V-shaped projectiles to test different V-angles.

The result? A 45-degree angle produced the fastest, tallest splashes, virtually matching what we observed in the human jumpers. V-angles greater than 45 degrees increased the risk of injury from landing flat on the back. We found it interesting that the jumpers very nearly hit the optimal angle largely through what appeared to be intuition and trial and error.

Digging deeper, we then built Manubot, a robot that mimics human body movements during manu jumps. It’s able to switch from a V-shape to a straight posture underwater. This is how we learned the optimal timing to maximize splash size.

For instance, for someone who’s 5-foot-7 and jumping from 1 meter, opening their body within 0.26 to 0.3 seconds of hitting the water resulted in the biggest splash. Open too soon or too late, and splash size is compromised.

One caveat: Humans are far more complex than any 3D-printed projectile or a Manubot. Factors such as weight distribution, flexibility and anatomical shape add nuance that our models can’t yet replicate.

For now, though, our findings highlight a simple truth: Creating the perfect manu splash isn’t the result of luck. Instead, it relies on a carefully tuned symphony of aerial and underwater maneuvers. So the next time you see someone spray everyone in the pool with a gigantic jump, remember – there’s a beautiful science behind the splash.

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.