After 124 Years, the Russian and Turkish Baths Are Still a Hot Spot

A longstanding bathhouse in the East Village has found ways to attract a new generation of customers — though they tend to come only every other week.

By ANNIE CORREA NY TIMES

On a recent Monday evening, it was hard to find a bit of bench at the Russian and Turkish Baths in the East Village. It was cold out, and people crowded the saunas — young, slim and in skimpy bathing suits.

The 124-year-old bathhouse on East 10th Street has long been a New York institution, a bona fide melting pot, where the sweat of celebrities mingles with that of rabbis and taxi drivers. It’s where downtown denizens have gone to detox and discuss the deeper things of life, and where Orthodox Jewish men have gone to convene, or to hide from their wives. For much of its existence it has been a men’s club for those far beyond the age of vanity.

Now, it’s a little different.

On that Monday, the patrons were still mainly male, but rather than bellies the size of airbags, many of them had washboard abs, and the discussion turned not to aches and pains but to Tinder dates. “The hipsters come in with their Groupons, sporting their tattoos and their man buns,” Rich Trince, 50, a longtime regular, said later.

The 124-year-old bathhouse on East 10th Street in the East Village. Credit Nicole Craine for The New York Times

The fabled baths — housed in a tenement basement and frequented by Frank Sinatra and John Belushi — have been claimed by the denizens of the new New York, as shvitzing has joined shuffleboard, brewing beer and pickling as a pastime enjoyed by millennials as well as retirees.

It was inevitable that change would come to the baths, with the East Village transformed and a bathhouse renaissance in full swing — there are the Russian banya of Brooklyn, the sumptuous Spa Castle in Queens, boutique spas in Manhattan like Aire and the Great Jones Spa, with its indoor waterfall.

But at the Russian and Turkish Baths, the new order reigns just half the time.

For years, the two Russian owners, Boris Tuberman and David Shapiro, have split the bathhouse business down the middle, running it on alternate weeks. (More on that in a moment.) They share expenses and the costs of repairs, but have separate corporations. A sign in the lobby reads, “Cards for Boris and David weeks must be purchased separately.”

In the past, the arrangement was easy enough to ignore, regulars say. Every other week, a different staff appeared behind the front desk, like two casts for the same play.

But some years back, Mr. Shapiro’s son Dmitry, 42, took over his father’s shift and began offering online promotions through companies like Groupon. On his weeks, the baths “became a little less eccentric,” said Jen Emma Hertel, one of Mr. Shapiro’s front-desk clerks, as they began to fill with young Brooklyn types and thrifty tourists.

Mr. Tuberman, however, resisted Groupon — and, for that matter, the Internet. “I don’t have memberships,” he said. “I have cards which don’t expire.”

On his weeks, there are no computers behind the counter, no swipe cards. The front-desk staff, which includes the owner and three Russian-speaking managers, uses punch cards and ledger books. Mr. Tuberman, 75, even disconnects the phone.

Customers can check whose week it is on the bath’s website.

The old system of alternating weeks has had various effects. One has been to thoroughly confuse people who arrive with a Groupon on the wrong week. It has also preserved, at least half the time, something of the old world of the shvitz.

On David weeks, as they are called, there is a new crowd. But on Boris weeks, the regulars are still “vaguely Slavic, vaguely paunchy,” as Charles Kramer, a 62-year-old lawyer and a regular for decades, described it, patting his belly. “You could blink your eyes and be back.”

On a recent Boris week, Warren Odze, a Broadway musician, had returned to the baths for the first time since the early 1980s. Many things were as he recalled: A little kitchen in the lobby served Russian-Jewish fare, and below ground, in a narrow space not much longer than a subway car, customers sat in towels in a misty Turkish steam room and a piping hot Russian sauna, received platzas, or therapeutic thrashings with oak branches, and dipped into an ice-cold pool.

Mr. Odze also noted the changes. The price of a day pass had quadrupled, to $40. There was a juice bar, a women’s locker room, women. Three decades ago, it was different. “There was nothing healthy about it,” he recalled. “It was steaks and big bagels. ‘Goodfellas,’ but the Jewish version.” In the basement then, Mr. Odze said, “it was old men basking and groaning, and I was scared of all of them.”

Mr. Odze said the bathhouse had become “trendy.” Still, he said, there was a remnant of the period he remembered. “I was happy to see there were a lot of, as they say among us Jews, schlubs.”

He added: “There were these old guys, and they were just there to sweat it out. They were not shy at all to let their big guts hang out. They were like, ‘I don’t care if you’re 20 and in a bikini, get out of my way.’  ”

Bathhouses were once ubiquitous in New York, the result of a city effort in the 19th century to keep residents in teeming immigrant neighborhoods clean before most homes had hot water.

The Tenth Street Baths, as they were long known, are thought to have opened in 1892. In their prime, as bath lore has it, they were a hangout for gangsters who talked business in the saunas and so preferred deaf-mute masseurs. Vodka was served in the lobby.

By the mid-1980s, when the elder Mr. Shapiro and Mr. Tuberman bought the baths, there was still one mute masseur, but the glory days had long passed. Most bathhouses in the city had closed decades earlier; almost all of those that remained were shut down by the authorities in 1985, as AIDS swept New York, for operating as gay gathering places.

The baths on 10th Street, which had a sign proclaiming the business the “straight place,” were among the few spared, but they were in shambles.

Mr. Tuberman had arrived in New York from Leningrad. His partner came from Siberia via Uzbekistan and Europe. (David Shapiro, who is 70 and lives in the Riverdale neighborhood of the Bronx, declined a request for an interview and provided answers through his son.) The two had been introduced by a mutual acquaintance. Along with a third partner, they paid $850,000 for the baths and the five-story building, with no money down, in 1985.

After the city crackdown, they found themselves with a virtual monopoly. But “it was pretty much a flophouse,” the younger Mr. Shapiro said. The previous owner, Al Modlin, had died in 1981 while giving a platza, and the family friend who took over was overwhelmed. The roof was caving in; the linoleum floors were peeling back. Men stayed overnight on bunk beds meant for naps.

Mr. Shapiro and Mr. Tuberman changed the locks, added tile floors, fixed the roof and added a deck modeled on a dacha, or Russian country house.

Business picked up, and they bought out the third partner. But privately, the owners’ relationship grew strained. They divided the days of the week; then they began to alternate weeks. The split became public in 1992 when a sign appeared on the lockers that read, “The bath is now operated by separate owners on alternative weeks.”

Both parties were vague about the origins of the conflict. “It wasn’t a single event,” Dmitry Shapiro said. “It’s just two people who are fundamentally different. My dad is very rigid and detail-oriented. And Boris is not a man who believes in rules. I don’t think he has a process. He does things on the fly.”

Mr. Tuberman called it a “profit divorce.”

“One day I come up with the idea,” he said. “God made seven days. Why not share them?”

A 1993 article in The New York Times warned of an “uncertain future” for the bathhouse and questioned whether it could survive the owners’ unusual business arrangement.

But more than two decades later, the baths are still here, and the owners are still alternating weeks.

The secret to their survival came down to one important business decision, Mr. Tuberman said recently. “I am a fan of U.S.A. which has made a great thing,” he said. He took a pen and scribbled something on the back of a punch card.

“Nobody has made that. Nobody give that. I’ve become very successful because of the golden word.”

He slid the card over.

It read, “CO ED.”

When Mr. Tuberman and Mr. Shapiro bought the baths, there had been one all-female shift per week. The new owners gradually made nearly all days coed. After an awkward period when both sexes shared one dressing room — where “the women found interesting ways of pulling their brassieres through their sleeves,” recalled Mr. Kramer — they raised a wall of lockers, creating the cramped men’s and women’s rooms that exist today.

The owners arguably ushered in the bathing trend by turning the baths coed and making what at the time were considered prissy additions: juice, mud masks and, later, an aromatherapy room. But in recent years they seem to have made few concessions to changing tastes.

The bathhouse still looks like a hostel with a flooded basement. The staff shouts in Russian as young men appear from downstairs with arms full of wet towels. The paint on the roof deck is peeling. The chocolate-brown towels have faded to tan.

In the era of Spa Castle, it’s still Spa Tenement.

They do not offer a Golden Caviar Pore Refining Facial. But you may help yourself to the industrial-grade pink soap in the showers.

And people keep coming.

On a recent Boris week, Mr. Tuberman sat behind the counter in a blue puffer jacket. He spends his off-weeks in Miami Beach, where he has another bathhouse of the same name. But on his weeks, he returns to New York to set the heat each day and sell punch cards.

“If you try and buy a day pass, Boris will say: ‘You’re stupid from the heat! You have to buy passes!’  ” said Julian Colucci, a 25-year-old video producer. “He would sell passes to a terminally ill person.”

Downstairs, that Friday, Boris regulars sat on a bench beside the pool like patrons of an old dive bar, their arms hanging over a railing draped with wet towels.

“I’ve been coming here 40 years,” Mitch Zykofsky, 57, a retired police sergeant, said. “It’s still a mystery to this day why Boris and David had that feud, but somehow I fell into the Boris camp.”

“Boris has been like a father to me,” said Gary Hope, 48, a former boxer who recently played a drill sergeant in a Halls cough drops commercial.

Behind them, men waded into the frigid pool and turned in circles with beatific grins, arms outstretched, like polar bears.

Julia Hughes, 30, a former East Villager who had moved to Brooklyn, said: “On Boris weeks, I find the characters are a little more eccentric, a little more fun. You never know what’s going to happen.”

But by broad consensus, it was the heat that most defined a Boris week.

“On Boris’s weeks, the hots are hotter, the colds are colder,” Chris Sullivan, a 35-year-old actor, said, a claim repeated by almost all Boris loyalists, including Mr. Tuberman himself.

Mr. Shapiro, when asked about that assessment, said: “I’ll let him say it. It makes him happy.” He added: “Hotter is not better, you know.”

Both would say only that the Russian Room, the hottest of the five steam rooms and saunas, was heated to the mid- to high 190s — about the temperature recommended to slow-cook a roast.

And so which weeks are actually hotter will remain a secret of the shvitz.

The following Monday, the start of a David week, the computers were back behind the desk, along with a friendly Midwestern woman, Ms. Hertel, swiping cards. In the lobby, beneath yellowing head shots, a young Groupon customer read a book by Amanda Palmer as she waited for her friend. It was quiet.

Downstairs, though, chatter echoed through the corridor and there was, indeed, a parade of tattoos.

In the aromatherapy room, a man described a visit to a tea shop where the cheapest item was a $21 pouch of loose-leaf plum-leaf tea. Someone else said, “She touched my knee, so then I touched her knee as well.”

Beside the pool, in the same baths where mobsters are said to have once made deals, a voice rose from the steam.

“Do you know anyone in children’s books?”

In the searing Russian Room, the three tiers of benches were full, so men stood around a water trough, trying to talk casually as they dripped sweat.

A couple held hands, closed their eyes and issued a guttural om.

In the corner, two older men took in the spectacle from a top bench. One wore a traditional Russian bathing cap made of yellow felt. The other had a wiry gray beard and rubber clogs. He spoke loudly about the baths, as if to command an audience, but no one was listening.

At some point he leaned forward as if to rise, but he found his path to the trough blocked by bodies. He put his hands around his mouth.

“Young man!” he said.

Everyone looked up.

“Hand me a bucket.”

By filling the baths using online coupons, Mr. Shapiro said, he is pulling them into the 21st century.

He pointed out that they had survived the economic downturn and transformed their block, where there is now a Pilates studio, a gluten-free cafe, a water bar.

If the baths had held their own against the competition, it was because of his innovations, he said. “Boris doesn’t have an email address,” he said.

Mr. Tuberman was more philosophical. “I know the reason I am here,” he said. “Life is so difficult. Russian, Jewish, Catholic, Muslim. They all fight. They can’t get along. I am the one who brought them all together. It’s like a church, but a different church. It’s like one big meeting.”

In other words, heat it and they will come.

Mr. Shapiro agreed that the baths were about tolerating others — namely Mr. Tuberman. “He is like the crazy uncle I never had,” he said, shaking his head. “There is no other way to describe him.”

But here’s another secret from the shvitz. On one evening, a familiar face was spotted in the saunas. His hair was slicked back, his cheeks beet red from the heat. It was the younger Mr. Shapiro. On a Boris week. He smiled sheepishly.

He later explained that during his workweek, he had little time to strip down and steam. And, he added, the owners’ relationship is not as bitter as it once was. Times had changed.

But one had to wonder if on Boris weeks, surrounded by the grumbling sorts that had always been his second family, Mr. Shapiro himself didn’t feel a little more at home.

The Brutalism of Ted Cruz

David Brooks NY Times

In 1997, Michael Wayne Haley was arrested after stealing a calculator from Walmart. This was a crime that merited a maximum two-year prison term. But prosecutors incorrectly applied a habitual offender law. Neither the judge nor the defense lawyer caught the error and Haley was sentenced to 16 years.

Eventually, the mistake came to light and Haley tried to fix it. Ted Cruz was solicitor general of Texas at the time. Instead of just letting Haley go for time served, Cruz took the case to the Supreme Court to keep Haley in prison for the full 16 years.

Some justices were skeptical. “Is there some rule that you can’t confess error in your state?” Justice Anthony Kennedy asked. The court system did finally let Haley out of prison, after six years.

The case reveals something interesting about Cruz’s character. Ted Cruz is now running strongly among evangelical voters, especially in Iowa. But in his career and public presentation Cruz is a stranger to most of what would generally be considered the Christian virtues: humility, mercy, compassion and grace. Cruz’s behavior in the Haley case is almost the dictionary definition of pharisaism: an overzealous application of the letter of the law in a way that violates the spirit of the law, as well as fairness and mercy.

Traditionally, candidates who have attracted strong evangelical support have in part emphasized the need to lend a helping hand to the economically stressed and the least fortunate among us. Such candidates include George W. Bush, Mike Huckabee and Rick Santorum.

Senator Ted Cruz of Texas with Bob Vander Plaats, one of the most influential leaders of Iowa’s politically activist evangelicals, in Rock Rapids last week.Ted Cruz’s Diligent Courting of Evangelicals Pays Off in Iowa

Sen. Marco Rubio of Florida, far right, highlighted his background — the son of a bartender and a maid — during the Kemp Forum in Columbia, S.C., on Saturday. Mr. Rubio also noted that Gov. John Kasich of Ohio, sitting next to him, understood the challenges of struggling Americans, with a father who delivered mail.Republican Candidates, Minus Donald Trump and Ted Cruz, Play Nice at Poverty Forum

But Cruz’s speeches are marked by what you might call pagan brutalism. There is not a hint of compassion, gentleness and mercy. Instead, his speeches are marked by a long list of enemies, and vows to crush, shred, destroy, bomb them. When he is speaking in a church the contrast between the setting and the emotional tone he sets is jarring.

Cruz lays down an atmosphere of apocalyptic fear. America is heading off “the cliff to oblivion.” After one Democratic debate he said, “We’re seeing our freedoms taken away every day, and last night was an audition for who would wear the jackboot most vigorously.”

As the Republican strategist Curt Anderson observed in Politico, there’s no variation in Cruz’s rhetorical tone. As is the wont of inauthentic speakers, everything is described as a maximum existential threat.

The fact is this apocalyptic diagnosis is ridiculous. The Obama administration has done things people like me strongly disagree with. But America is in better economic shape than any other major nation on earth. Crime is down. Abortion rates are down. Fourteen million new jobs have been created in five years.

Obama has championed a liberal agenda, but he hasn’t made the country unrecognizable. In 2008, federal spending accounted for about 20.3 percent of gross domestic product. In 2015, it accounted for about 20.9 percent.

But Cruz manufactures an atmosphere of menace in which there is no room for compassion, for moderation, for anything but dismantling and counterattack. And that is what he offers. Cruz’s programmatic agenda, to the extent that it exists in his speeches, is to destroy things: destroy the I.R.S., crush the “jackals” of the E.P.A., end funding for Planned Parenthood, reverse Obama’s executive orders, make the desert glow in Syria, destroy the Iran nuclear accord.

Some of these positions I agree with, but the lack of any positive emphasis, any hint of reform conservatism, any aid for the working class, or even any humane gesture toward cooperation is striking.

Ted Cruz didn’t come up with this hard, combative and gladiatorial campaign approach in isolation. He’s always demonstrated a tendency to bend his position — whether immigration or trade — to what suits him politically. This approach works because in the wake of the Obergefell v. Hodges court decision on same-sex marriage, many evangelicals feel they are being turned into pariahs in their own nation.

Cruz exploits and exaggerates that fear. But he reacts to Obergefell in exactly the alienating and combative manner that is destined to further marginalize evangelicals, that is guaranteed to bring out fear-driven reactions and not the movement’s highest ideals.

The best conservatism balances support for free markets with a Judeo-Christian spirit of charity, compassion and solidarity. Cruz replaces this spirit with Spartan belligerence. He sows bitterness, influences his followers to lose all sense of proportion and teaches them to answer hate with hate. This Trump-Cruz conservatism looks more like tribal, blood and soil European conservatism than the pluralistic American kind.

Evangelicals and other conservatives have had their best influence on American politics when they have proceeded in a spirit of personalism — when they have answered hostility with service and emphasized the infinite dignity of each person. They have won elections as happy and hopeful warriors. Ted Cruz’s brutal, fear-driven, apocalypse-based approach is the antithesis of that.

NATURE | NEWS FEATURE 

The physics of life Gabriel Popkin

From flocking birds to swarming molecules, physicists are seeking to understand 'active matter' — and looking for a fundamental theory of the living world.

First, Zvonimir Dogic and his students took microtubules — threadlike proteins that make up part of the cell's internal 'cytoskeleton' — and mixed them with kinesins, motor proteins that travel along these threads like trains on a track. Then the researchers suspended droplets of this cocktail in oil and supplied it with the molecular fuel known as adenosine triphosphate (ATP).

To the team's surprise and delight, the molecules organized themselves into large-scale patterns that swirled on each droplet's surface. Bundles of microtubules linked by the proteins moved together “like a person crowd-surfing at a concert”, says Dogic, a physicist at Brandeis University in Waltham, Massachusetts.

Lab-made droplets roll themselves

With these experiments, published1 in 2012, Dogic's team created a new kind of liquid crystal. Unlike the molecules in standard liquid-crystal displays, which passively form patterns in response to electric fields, Dogic's components were active. They propelled themselves, taking energy from their environment — in this case, from ATP. And they formed patterns spontaneously, thanks to the collective behaviour of thousands of units moving independently.

These are the hallmarks of systems that physicists call active matter, which have become a major subject of research in the past few years. Examples abound in the natural world — among them the leaderless but coherent flocking of birds and the flowing, structure-forming cytoskeletons of cells. They are increasingly being made in the laboratory: investigators have synthesized active matter using both biological building blocks such as microtubules, and synthetic components including micrometre-scale, light-sensitive plastic 'swimmers' that form structures when someone turns on a lamp. Production of peer-reviewed papers with 'active matter' in the title or abstract has increased from less than 10 per year a decade ago to almost 70 last year, and several international workshops have been held on the topic in the past year.

The secret of life

Researchers hope that this work will lead them to a complete, quantitative theory of active matter. Such a theory would build on physicists' century-old theory of statistical mechanics, which explains how the motion of atoms and molecules gives rise to everyday phenomena such as heat, temperature and pressure. But it could go much further, providing a mathematical framework for still-mysterious biological processes such as how cells move things around, how they create and maintain their shapes and how they divide. “We want a theory of the mechanics and statistics of living matter with a status comparable to what's already been done for collections of dead particles,” says Sriram Ramaswamy, a physicist and director of the Tata Institute of Fundamental Research's Centre for Interdisciplinary Sciences in Hyderabad, India.

It could be a while before that want is satisfied, however. Experimentalists are only beginning to gain control of active materials in the lab. Even the most enthusiastic proponents of this research admit that no one has yet produced a theory of active matter that describes the behaviour of everything from cell parts to birds. And if such a theory did exist, it's far from certain that mainstream biologists would see value in it. For biologists, the idea that living matter is active “would be just so obvious as to not really contain very much information”, says Jonathon Howard, a molecular biophysicist at Yale University in New Haven, Connecticut.

Scientists print self-assembling 'living tissue'

But that has not kept proponents from imagining applications such as self-assembling artificial tissue, self-pumping microfluidic devices and new bio-inspired materials — although researchers admit that such ideas are still far from being realized. “I think it's too early for the field to have an application, because we're still kind of astonished at what can happen,” says Andreas Bausch, a physicist at the Technical University of Munich in Germany — “but I do think the field needs somebody doing it.”

All together now

All known life forms are based on self-propelled entities uniting to create large-scale structures and movements. If this didn't happen, organisms would be limited to using much slower, passive processes such as diffusion to move DNA and proteins around inside cells or tissues, and many of life's complex structures and functions might never have evolved. Biologists and physicists have speculated for decades about the general principles of living matter, but research on cellular processes has focused on identifying the dizzying array of molecules involved, rather than on working out the principles by which they self-organize. As a result, what is now known as active-matter research did not really get under way until the mid-1990s.

The tiniest Lego: a tale of nanoscale motors, rotors, switches and pumps

One of the most influential early experiments was conducted by the team of Stanislas Leibler, a biophysicist who was then at Princeton University in New Jersey and is now at the Rockefeller University in New York. The group was among the first to show that complex, life-like structures could self-assemble from microtubules and a few proteins supplied with ATP2. Around the same time, an influential model of active matter was being developed by Tamás Vicsek, a theoretical biophysicist at Eötvös Loránd University in Budapest. In the early 1990s, Vicsek was trying to account for the collective motions of bird flocks, bacterial colonies and cytoskeleton components when he realized that no existing theory would work. “It's not like equilibrium statistical mechanics, where you take a book and you find what to do,” says physicist Jean-François Joanny of the Curie Institute in Paris.

Instead, Vicsek found a starting point in a model of magnetic materials developed in 1928 by German physicist Werner Heisenberg. Heisenberg imagined each atom as a freely rotating bar magnet, and found that large-scale magnetism emerges when interactions between these atomic magnets cause the majority of them to align. To explain active matter, Vicsek replaced the tiny magnets with moving 'arrows' symbolizing particles with velocities that aligned with the average velocity of their neighbours — albeit with a certain amount of random error. That led to what is now known as Vicsek's flocking model3. His simulations showed that when enough arrows were packed into a small enough space, they began to move in patterns that closely resembled the familiar movements of bird flocks and fish schools (see 'Smart swarms').

“I got excited,” recalls Vicsek, whose 1995 paper3 on the model has received more than 3,500 citations. “I was walking up and down the corridor and told people I had designed the moving version of the Heisenberg model.”

One physicist attracted to this idea was John Toner, who heard Vicsek give a talk on it in 1994. Toner, now at the University of Oregon in Eugene, saw that Vicsek's swarming arrows could be modelled as a continuous fluid. He took the standard equations for hydrodynamics, which describe fluid flow in everything from tea kettles to oceans, and modified them to account for how individual particles use energy4. Toner's fluid model and Vicsek's discrete-particle model gave essentially the same predictions for a wide range of phenomena, and launched a cottage industry of active-matter simulations.

Precision formation flight astounds scientists

There was only one problem. Whereas the number of simulations was skyrocketing, says physicist Denis Bartolo of the École Normale Supérieure in Lyons, France, “the number of quantitative experiments was constant and very close to zero”. Practical work was challenging: no one could hope to do controlled experiments with 10,000 real birds or fish. And at the microscopic scale, few scientists were familiar with both the necessary theoretical work — being published mainly in physics journals — and the biological lab techniques needed to purify cellular components.

Practical magic

Only in the late 2000s did the theoretical and experimental pieces begin coming together. Bausch led one of the first precise, quantitative experiments. He and his colleagues mixed actin, a filament that forms most of the cytoskeleton of complex cells, with myosin, a molecular motor that 'walks' on actin and makes muscles contract. The researchers added myosin's natural fuel, ATP, then put the mixture on a microscope slide and watched. “We didn't do anything; we just added the stuff,” Bausch says. At low concentrations, the actin filaments swam around without recognizable order. But at higher densities, they formed pulsating clusters, swirls and bands. Bausch and his colleagues immediately recognized and quantified phase transitions of the kind that Vicsek and others had predicted. Their 2010 paper5 helped to ignite the experimental active-matter field.

Among the studies that followed were Dogic's 2012 microtubule experiments1, which used another walking protein, kinesin. The resulting patterns were much more complex and dynamic than the ones Bausch saw: the flowing microtubules looked like fingerprint whorls in motion. Dogic and his team also noticed that the orderly alignment of this flow would occasionally break down and produce 'defects': discontinuities in the pattern that resemble converging longitude lines at the North and South poles. These defects were dynamic, moving around like self-propelled particles.

No theory at the time could account for this behaviour. But in 2014, Dogic teamed up with Bausch and physicist Cristina Marchetti of Syracuse University in New York to describe the behaviour of active liquid crystals swirling on spherical vesicles in terms of the movement of defects rather than of individual crystal elements6. Furthermore, the group found that it could tune the defects' motion by adjusting the vesicle's diameter and surface tension, suggesting a possible way to control an active crystal.

“We're still kind of astonished at what can happen.”

Dogic and his students are now trying to do just that. By studying the spontaneous flows of microtubules and proteins confined in small, doughnut-shaped containers, they hope to lay the groundwork for a self-pumping fluid that could move molecules around in microfluidic devices similar to those that are becoming increasingly common in experimental biology, medicine and industry. Active matter “changes our ideas of what materials can do”, says Dogic.

But any industrial application will have to overcome at least one major roadblock. The biological materials currently used in active-matter experiments are expensive and time-consuming to purify — Dogic's microtubules come from cow brains, and Bausch uses actin from rabbit muscle — and they last only a short time in the lab. Until a cheap, robust, off-the-shelf source of active-matter materials can be found, commercial use is unlikely, says Bausch.

Autonomous drones flock like birds

Advances in synthetic active materials may show the way forward. In 2013, New York University physicist Paul Chaikin and his colleagues described making particles of haematite, an iron oxide mineral, inside a spherical polymer7. When the scientists placed these 'swimmers' in a solution of hydrogen peroxide and exposed them to blue light, a chemical reaction caused the particles to move around spontaneously, clumping and unclumping like groups of people at a cocktail party.

In 2013, Bartolo and his colleagues reported large-scale flows using even simpler plastic spheres in a conducting fluid8. When the researchers turned on an electric field, the spheres began rotating in random directions. At high enough densities, interactions between nearby spheres caused them to spontaneously roll, flock-like, in the same direction.

Such lab-made materials remain primitive, however, compared with those produced in cells by 4 billion years of evolution. Dogic notes that the kinesins he uses are much more efficient than any human-made motors at converting energy to motion. And Bartolo is also quick to discourage talk of short-term pay-offs. “I'm not targeting a specific application,” he says of his rotating plastic spheres.

Possible applications aside, active matter excites scientists because it so closely resembles the most complex self-organizing systems known: living organisms. In 2011, Dogic and his colleagues reported9 that microtubule bundles anchored at one end to air bubbles on a microscope slide beat in synchronized, wave-like patterns eerily reminiscent of the hair-like cilia and flagella that protrude from the surfaces of some cells. And in his 2012 paper1, he noted a striking similarity between his microtubule flows and cytoplasmic streaming, a process in which cytoskeletal filaments team up to whisk a cell's contents around like “a giant washing machine”, he says.

Researchers create 1,000-robot swarm

The resemblance between lab-prepared active matter and living things can be uncanny, agrees Jennifer Ross, a physicist at the University of Massachusetts Amherst. At talks, she has shown videos of spherical microtubule–kinesin systems and asked audience members whether they think they are seeing a real cell. “Whenever I present these to cell biologists in particular, they are always fooled,” she says.

But something can look and act like a living organism without actually following the same rules, cautions Howard. He points out that Dogic's group created something that looks and acts very much like a cilium or flagellum with its multitude of proteins — but that may, in fact, work very differently. “There's something in there about the underlying mechanism, but it's extremely abstract,” he says.

Is it enough?

To probe whether active-matter theory can reveal biological mechanisms, Daniel Needleman, a biophysicist at Harvard University in Cambridge, Massachusetts, studied the spindle: a microtubule-based structure that controls the separation of chromosomes during cell division. He wanted to test the idea, suggested by earlier theories and experiments, that short-range microtubule–kinesin interactions by themselves were sufficient to yield spindle-like structures. He first used sophisticated microscopes to examine extracts from frog egg cells, quantifying microtubule density, orientation and stresses during spindle formation. “It really was not clear at all until Dan came along that you could measure all these things,” says Howard.

Needleman then merged his measurements with models of how active matter self-organizes. In 2014, he and Jan Brugués, a biologist at the Max Planck Institute of Molecular Cell Biology and Genetics in Dresden, Germany, reported that, consistent with theory, the interactions they observed among closely spaced microtubules are enough to produce the spindle and keep it stable10. “People have argued that you need more complex processes,” says Needleman. “But the fact that one can understand so much of the spindle without invoking any of that shows that it's certainly not necessary.”

Mathematical time law governs crowd flow

Others are using ideas from active matter to probe how large numbers of cells organize in processes such as tissue growth, wound healing and the spread of tumours. Theorists including Marchetti, Joanny and Frank Jülicher of the Max Planck Institute for the Physics of Complex Systems in Dresden have modelled tissues11 and tumours12 as flowing cells that self-organize through short-range cell-to-cell interactions rather than chemical signals. Experimentalists are testing such ideas, for instance, by showing that active-matter theory can help to describe cell organization in a developing fruit-fly wing13.

Some biologists hope that such studies will reveal the fundamental principles that govern how cells divide, take shape or move. “It's like Linnaean classification before Darwin came along,” says biologist Tony Hyman of the Max Planck Institute of Molecular Cell Biology and Genetics. “We've got all these molecules, just like they had all those species, and we need to put some kind of order, some kind of reason behind it all.” Active matter, Hyman thinks, could provide that reason.

But even enthusiasts admit that mainstream biologists may need convincing. “We used to get a lot of papers rejected at the beginning,” says Hyman — in part because the manuscripts' heavy use of mathematics made it hard to find reviewers. Even the phrase 'active matter' may hinder communication, adds Howard. “It's kind of a physics-y term.”

Still, Howard and Hyman hope that acceptance will be aided by increasing convergence between fields. Among biologists, says Hyman, “I think the new generation coming along will be trained in physics from the beginning.”

And that's good, adds Stephan Grill, a biophysicist at the Technical University of Dresden, because progress in active matter calls for scientists who are at the cutting edge of both physics and biology. “The pot of gold is at the interface,” he says, “but you have to push both fields to their limits.”