Astronomers spotted shock waves shaking the web of the universe for the first time

For the first time, astronomers have caught a glimpse of shock waves rippling along strands of the cosmic web — the enormous tangle of galaxies, gas and dark matter that fills the observable universe.

Combining hundreds of thousands of radio telescope images revealed the faint glow cast as shock waves send charged particles flying through the magnetic fields that run along the cosmic web. Spotting these shock waves could give astronomers a better look at these large-scale magnetic fields, whose properties and origins are largely mysterious, researchers report in the Feb. 17 Science Advances.
Finally, astronomers “can confirm what so far has only been predicted by simulations — that these shock waves exist,” says astrophysicist Marcus Brüggen of the University of Hamburg in Germany, who was not involved in the new study.

At its grandest scale, our universe looks something like Swiss cheese. Galaxies aren’t distributed evenly through space but rather are clumped together in enormous clusters connected by ropy filaments of dilute gas, galaxies and dark matter and separated by not-quite-empty voids (SN: 10/3/19).

Tugged by gravity, galaxy clusters merge, filaments collide, and gas from the voids falls onto filaments and clusters. In simulations of the cosmic web, all that action consistently sets off enormous shock waves in and along filaments.

Filaments make up most of the cosmic web but are much harder to spot than galaxies (SN: 1/20/14). While scientists have observed shock waves around galaxy clusters before, shocks in filaments “have never been really seen,” says astronomer Reinout van Weeren of Leiden University in the Netherlands, who was not involved in the study. “But they should be basically all around the cosmic web.”

Shock waves around filaments would accelerate charged particles through the magnetic fields that suffuse the cosmic web (SN: 6/6/19). When that happens, the particles emit light at wavelengths that radio telescopes can detect — though the signals are very weak.
A single shock wave in a filament “would look like nothing, it’d look like noise,” says radio astronomer Tessa Vernstrom of the International Centre for Radio Astronomy Research in Crawley, Australia.

Instead of looking for individual shock waves, Vernstrom and her colleagues combined radio images of more than 600,000 pairs of galaxy clusters close enough to be connected by filaments to create a single “stacked” image. This amplified weak signals and revealed that, on average, there is a faint radio glow from the filaments between clusters.

“When you can dig below the noise and still actually get a result — to me, that’s personally exciting,” Vernstrom says.

The faint signal is highly polarized, meaning that the radio waves are mostly aligned with one another. Highly polarized light is unusual in the cosmos, but it is expected from radio light cast by shock waves, van Weeren says. “So that’s really, I think, very good evidence for the fact that the shocks are likely indeed present.”
The discovery goes beyond confirming the predictions of cosmic web simulations. The polarized radio emissions also offer a rare peek at the magnetic fields that permeate the cosmic web, if only indirectly.

“These shocks,” Brüggen says, “are really able to show that there are large-scale magnetic fields that form [something] like a sheath around these filaments.”

He, van Weeren and Vernstrom all note that it’s still an open question how cosmic magnetic fields arose in the first place. The role these fields play in shaping the cosmic web is equally mysterious.

“It’s one of the four fundamental forces of nature, right? Magnetism,” Vernstrom says. “But at least on these large scales, we don’t really know how important it is.”

What the first look at the genetics of Chernobyl’s dogs revealed

For generations of dogs, home is the radioactive remains of the Chernobyl Nuclear Power Plant.

In the first genetic analysis of these animals, scientists have discovered that dogs living in the power plant industrial area are genetically distinct from dogs living farther away.

Though the team could distinguish between dog populations, the researchers did not pinpoint radiation as the reason for any genetic differences. But future studies that build on the findings, reported March 3 in Science Advances, may help uncover how radioactive environments leave their mark on animal genomes.
That could have implications for other nuclear disasters and even human space travel, says Timothy Mousseau, an evolutionary ecologist at the University of South Carolina in Columbia. “We have high hopes that what we learn from these dogs … will be of use for understanding human exposures in the future,” he says.

Since his first trip in 1999, Mousseau has stopped counting how many times he’s been to Chernobyl. “I lost track after we hit about 50 visits.”

He first encountered Chernobyl’s semi-feral dogs in 2017, on a trip with the Clean Futures Fund+, an organization that provides veterinary care to the animals. Not much is known about how local dogs survived after the nuclear accident. In 1986, an explosion at one of the power plant’s reactors kicked off a disaster that lofted vast amounts of radioactive isotopes into the air. Contamination from the plant’s radioactive cloud largely settled nearby, in a region now called the Chernobyl Exclusion Zone.

Dogs have lived in the area since the disaster, fed by Chernobyl cleanup workers and tourists. Some 250 strays were living in and around the power plant, among spent fuel-processing facilities and in the shadow of the ruined reactor. Hundreds more roam farther out in the exclusion zone, an area about the size of Yosemite National Park.
During Mousseau’s visits, his team collected blood samples from these dogs for DNA analysis, which let the researchers map out the dogs’ complex family structures. “We know who’s related to who,” says Elaine Ostrander, a geneticist at the National Human Genome Research Institute in Bethesda, Md. “We know their heritage.”

The canine packs are not just a hodgepodge of wild feral dogs, she says. “There are actually families of dogs breeding, living, existing in the power plant,” she says. “Who would have imagined?”

Dogs within the exclusion zone share ancestry with German shepherds and other shepherd breeds, like many other free-breeding dogs from Eastern Europe, the team reports. And though their work revealed that dogs in the power plant area look genetically different from dogs in Chernobyl City, about 15 kilometers away, the team does not know whether radiation caused these differences or not, Ostrander says. The dogs may be genetically distinct simply because they’re living in a relatively isolated area.

The new finding is not so surprising, says Jim Smith, an environmental scientist at the University of Portsmouth in England. He was not part of the new study but has worked in this field for decades. He’s concerned that people might assume “that the radiation has something to do with it,” he says. But “there’s no evidence of that.”

Scientists have been trying to pin down how radiation exposure at Chernobyl has affected wildlife for decades (SN: 5/2/14). “We’ve been looking at the consequences for birds and rodents and bacteria and plants,” Mousseau says. His team has found animals with elevated mutation rates, shortened life spans and early-onset cataracts.

It’s not easy to tease out the effects of low-dose radiation among other factors, Smith says. “[These studies] are so hard … there’s lots of other stuff going in the natural environment.” What’s more, animals can reap some benefits when humans leave contaminated zones, he says.

How, or if, radiation damage is piling up in dogs’ genomes is something the team is looking into now, Ostrander says. Knowing the dogs’ genetic backgrounds will make it easier to spot any radiation red flags, says Bridgett vonHoldt, an evolutionary geneticist at Princeton University, who was not involved in the work.

“I feel like it’s a cliffhanger,” she says. “I want to know more.”

Google’s quantum computer reached an error-correcting milestone

To shrink error rates in quantum computers, sometimes more is better. More qubits, that is.

The quantum bits, or qubits, that make up a quantum computer are prone to mistakes that could render a calculation useless if not corrected. To reduce that error rate, scientists aim to build a computer that can correct its own errors. Such a machine would combine the powers of multiple fallible qubits into one improved qubit, called a “logical qubit,” that can be used to make calculations (SN: 6/22/20).

Scientists now have demonstrated a key milestone in quantum error correction. Scaling up the number of qubits in a logical qubit can make it less error-prone, researchers at Google report February 22 in Nature.
Future quantum computers could solve problems impossible for even the most powerful traditional computers (SN: 6/29/17). To build those mighty quantum machines, researchers agree that they’ll need to use error correction to dramatically shrink error rates. While scientists have previously demonstrated that they can detect and correct simple errors in small-scale quantum computers, error correction is still in its early stages (SN: 10/4/21).

The new advance doesn’t mean researchers are ready to build a fully error-corrected quantum computer, “however, it does demonstrate that it is indeed possible, that error correction fundamentally works,” physicist Julian Kelly of Google Quantum AI said in a news briefing February 21.
Logical qubits store information redundantly in multiple physical qubits. That redundancy allows a quantum computer to check if any mistakes have cropped up and fix them on the fly. Ideally, the larger the logical qubit, the smaller the error rate should be. But if the original qubits are too faulty, adding in more of them will cause more problems than it solves.

Using Google’s Sycamore quantum chip, the researchers studied two different sizes of logical qubits, one consisting of 17 qubits and the other of 49 qubits. After making steady improvements to the performance of the original physical qubits that make up the device, the researchers tallied up the errors that still slipped through. The larger logical qubit had a lower error rate, about 2.9 percent per round of error correction, compared to the smaller logical qubit’s rate of about 3.0 percent, the researchers found.
That small improvement suggests scientists are finally tiptoeing into the regime where error correction can begin to squelch errors by scaling up. “It’s a major goal to achieve,” says physicist Andreas Wallraff of ETH Zurich, who was not involved with the research.

However, the result is only on the cusp of showing that error correction improves as scientists scale up. A computer simulation of the quantum computer’s performance suggests that, if the logical qubit’s size were increased even more, its error rate would actually get worse. Additional improvement to the original faulty qubits will be needed to enable scientists to really capitalize on the benefits of error correction.

Still, milestones in quantum computation are so difficult to achieve that they’re treated like pole jumping, Wallraff says. You just aim to barely clear the bar.

This robot automatically tucks its limbs to squeeze through spaces

Inspired by how ants move through narrow spaces by shortening their legs, scientists have built a robot that draws in its limbs to navigate constricted passages.

The robot was able to hunch down and walk quickly through passages that were narrower and shorter than itself, researchers report January 20 in Advanced Intelligent Systems. It could also climb over steps and move on grass, loose rock, mulch and crushed granite.

Such generality and adaptability are the main challenges of legged robot locomotion, says robotics engineer Feifei Qian, who was not involved in the study. Some robots have specialized limbs to move over a particular terrain, but they cannot squeeze into small spaces (SN: 1/16/19).
“A design that can adapt to a variety of environments with varying scales or stiffness is a lot more challenging, as trade-offs between the different environments need to be considered,” says Qian, of the University of Southern California in Los Angeles.

For inspiration, researchers in the new study turned to ants. “Insects are really a neat inspiration for designing robot systems that have minimal actuation but can perform a multitude of locomotion behaviors,” says Nick Gravish, a roboticist at the University of California, San Diego (SN: 8/16/18). Ants adapt their posture to crawl through tiny spaces. And they aren’t perturbed by uneven terrain or small obstacles. For example, their legs collapse a bit when they hit an object, Gravish says, and the ants continue to move forward quickly.

Gravish and colleagues built a short, stocky robot — about 30 centimeters wide and 20 centimeters long — with four wavy, telescoping limbs. Each limb consists of six nested concentric tubes that can draw into each other. What’s more, the limbs do not need to be actively powered or adjusted to change their overall length. Instead, springs that connect the leg segments automatically allow the legs to contract when the robot navigates a narrow space and stretch back out in an open space. The goal was to build mechanically intelligent structures rather than algorithmically intelligent robots.

“It’s likely faster than active control, [which] requires the robot to first sense the contact with the environment, compute the suitable action and then send the command to its motors,” Qian says, about these legs. Removing the sensing and computing components can also make the robots small, cheap and less power hungry.

The robot could modify its body width and height to achieve a larger range of body sizes than other similar robots. The leg segments contracted into themselves to let the robot wiggle through small tunnels and sprawled out when under low ceilings. This adaptability let the robot squeeze into spaces as small as 72 percent its full width and 68 percent its full height.
Next, the researchers plan to actively control the stiffness of the springs that connect the leg segments to tune the motion to terrain type without consuming too much power. “That way, you can keep your leg long when you are moving on open ground or over tall objects, but then collapse down to the smallest possible shape in confined spaces,” Gravish says.
Such small-scale, minimal robots are easy to produce and can be quickly tweaked to explore complex environments. However, despite being able to walk across different terrains, these robots are, for now, too fragile for search-and-rescue, exploration or biological monitoring, Gravish says.

The new robot takes a step closer to those goals, but getting there will take more than just robotics, Qian says. “To actually achieve these applications would require an integration of design, control, sensing, planning and hardware advancement.”

But that’s not Gravish’s interest. Instead, he wants to connect these experiments back to what was observed in the ants originally and use the robots to ask more questions about the rules of locomotion in nature (SN: 1/16/20).

“I really would like to understand how small insects are able to move so rapidly across certain unpredictable terrain,” he says. “What is special about their limbs that enables them to move so quickly?”

The Kuiper Belt’s dwarf planet Quaoar hosts an impossible ring

The dwarf planet Quaoar has a ring that is too big for its metaphorical fingers. While all other rings in the solar system lie within or near a mathematically determined distance of their parent bodies, Quaoar’s ring is much farther out.

“For Quaoar, for the ring to be outside this limit is very, very strange,” says astronomer Bruno Morgado of the Federal University of Rio de Janeiro. The finding may force a rethink of the rules governing planetary rings, Morgado and colleagues say in a study published February 8 in Nature.
Quaoar is an icy body about half the size of Pluto that’s located in the Kuiper Belt at the solar system’s edge (SN: 8/23/22). At such a great distance from Earth, it’s hard to get a clear picture of the world.

So Morgado and colleagues watched Quaoar block the light from a distant star, a phenomenon called a stellar occultation. The timing of the star winking in and out of view can reveal details about Quaoar, like its size and whether it has an atmosphere.

The researchers took data from occultations from 2018 to 2020, observed from all over the world, including Namibia, Australia and Grenada, as well as space. There was no sign that Quaoar had an atmosphere. But surprisingly, there was a ring. The finding makes Quaoar just the third dwarf planet or asteroid in the solar system known to have a ring, after the asteroid Chariklo and the dwarf planet Haumea (SN: 3/26/14; SN: 10/11/17).

Even more surprisingly, “the ring is not where we expect,” Morgado says.
Known rings around other objects lie within or near what’s called the Roche limit, an invisible line where the gravitational force of the main body peters out. Inside the limit, that force can rip a moon to shreds, turning it into a ring. Outside, the gravity between smaller particles is stronger than that from the main body, and rings will coalesce into one or several moons.

“We always think of [the Roche limit] as straightforward,” Morgado says. “One side is a moon forming, the other side is a ring stable. And now this limit is not a limit.”

For Quaoar’s far-out ring, there are a few possible explanations, Morgado says. Maybe the observers caught the ring at just the right moment, right before it turns into a moon. But that lucky timing seems unlikely, he notes.

Maybe Quaoar’s known moon, Weywot, or some other unseen moon contributes gravity that holds the ring stable somehow. Or maybe the ring’s particles are colliding in such a way that they avoid sticking together and clumping into moons.

The particles would have to be particularly bouncy for that to work, “like a ring of those bouncy balls from toy stores,” says planetary scientist David Jewitt of UCLA, who was not involved in the new work.

The observation is solid, says Jewitt, who helped discover the first objects in the Kuiper Belt in the 1990s. But there’s no way to know yet which of the explanations is correct, if any, in part because there are no theoretical predictions for such far-out rings to compare with Quaoar’s situation.

That’s par for the course when it comes to the Kuiper Belt. “Everything in the Kuiper Belt, basically, has been discovered, not predicted,” Jewitt says. “It’s the opposite of the classical model of science where people predict things and then confirm or reject them. People discover stuff by surprise, and everyone scrambles to explain it.”

More observations of Quaoar, or more discoveries of seemingly misplaced rings elsewhere in the solar system, could help reveal what’s going on.

“I have no doubt that in the near future a lot of people will start working with Quaoar to try to get this answer,” Morgado says.

Muon scanning hints at mysteries within an ancient Chinese wall

For nearly 650 years, the fortress walls in the Chinese city of Xi’an have served as a formidable barrier around the central city. At 12 meters high and up to 18 meters thick, they are impervious to almost everything — except subatomic particles called muons.

Now, thanks to their penetrating abilities, muons may be key to ensuring that the walls that once protected the treasures of the first Ming Dynasty — and are now a national architectural treasure in their own right — stand for centuries more.

A refined detection method has provided the highest-resolution muon scans yet produced of any archaeological structure, researchers report in the Jan. 7 Journal of Applied Physics. The scans revealed interior density fluctuations as small as a meter across inside one section of the Xi’an ramparts. The fluctuations could be signs of dangerous flaws or “hidden structures archaeologically interesting for discovery and investigation,” says nuclear physicist Zhiyi Liu of Lanzhou University in China.
Muons are like electrons, only heavier. They rain down all over the planet, produced when charged particles called cosmic rays hit the atmosphere. Although muons can travel deep into earth and stone, they are scattered or absorbed depending on the material they encounter. Counting the ones that pass through makes them useful for studying volcano interiors, scanning pyramids for hidden chambers and even searching for contraband stashed in containers impervious to X-rays (SN: 4/22/22).

Though muons stream down continuously, their numbers are small enough that the researchers had to deploy six detectors for a week at a time to collect enough data for 3-D scans of the rampart.

It’s now up to conservationists to determine how to address any density fluctuations that might indicate dangerous flaws, or historical surprises, inside the Xi’an walls.

Chicken DNA is replacing the genetics of their ancestral jungle fowl

Today’s red jungle fowl — the wild forebears of the domesticated chicken — are becoming more chickenlike. New research suggests that a large proportion of the wild fowl’s DNA has been inherited from chickens, and relatively recently.

Ongoing interbreeding between the two birds may threaten wild jungle fowl populations’ future, and even hobble humans’ ability to breed better chickens, researchers report January 19 in PLOS Genetics.

Red jungle fowl (Gallus gallus) are forest birds native to Southeast Asia and parts of South Asia. Thousands of years ago, humans domesticated the fowl, possibly in the region’s rice fields (SN: 6/6/22).
“Chickens are arguably the most important domestic animal on Earth,” says Frank Rheindt, an evolutionary biologist at the National University of Singapore. He points to their global ubiquity and abundance. Chicken is also one of the cheapest sources of animal protein that humans have.

Domesticated chickens (G. gallus domesticus) were known to be interbreeding with jungle fowl near human settlements in Southeast Asia. Given the unknown impacts on jungle fowl and the importance of chickens to humankind, Rheindt and his team wanted to gather more details. Wild jungle fowl contain a store of genetic diversity that could serve as a crucial resource for breeding chickens resistant to diseases or other threats.

The researchers analyzed and compared the genomes — the full complement of an organism’s DNA — of 63 jungle fowl and 51 chickens from across Southeast Asia. Some of the jungle fowl samples came from museum specimens collected from 1874 through 1939, letting the team see how the genetic makeup of jungle fowl has changed over time.

Over the last century or so, wild jungle fowl’s genomes have become increasingly similar to chickens’. Between about 20 and 50 percent of the genomes of modern jungle fowl originated in chickens, the team found. In contrast, many of the roughly 100-year-old jungle fowl had a chicken-ancestry share in the range of a few percent.

The rapid change probably comes from human communities expanding into the region’s wilderness, Rheindt says. Most modern jungle fowl live in close vicinity to humans’ free-ranging chickens, with which they frequently interbreed.

Such interbreeding has become “almost the norm now” for any globally domesticated species, Rheindt says, such as dogs hybridizing with wolves and house cats crossing with wildcats. Pigs, meanwhile, are mixing with wild boars and ferrets with polecats.
Wild populations that interbreed with their domesticated counterparts could pick up physical or behavioral traits that change how the hybrids function in their ecosystem, says Claudio Quilodrán, a conservation geneticist at the University of Geneva not involved with this research.

The effect is likely to be negative, Quilodrán says, since some of the traits coming into the wild population have been honed for human uses, not for survival in the local environment.

Wild jungle fowl have lost their genetic diversity as they’ve interbred too. The birds’ heterozygosity — a measure of a population’s genetic diversity — is now just a tenth of what it was a century ago.

“This result is initially counterintuitive,” Rheindt says. “If you mix one population with another, you would generally expect a higher genetic diversity.”

But domesticated chickens have such low genetic diversity that certain versions of jungle fowl genes are being swept out of the population by a tsunami of genetic homogeneity. The whittling down of these animals’ genetic toolkit may leave them vulnerable to conservation threats.

“Having lots of genetic diversity within a species increases the chance that certain individuals contain the genetic background to adapt to a varied range of different environmental changes and diseases,” says Graham Etherington, a computational biologist at the Earlham Institute in Norwich, England, who was not involved with this research.

A shallower jungle fowl gene pool could also mean diminished resources for breeding better chickens. The genetics of wild relatives are sometimes used to bolster the disease or pest resistance of domesticated crop plants. Jungle fowl genomes could be similarly valuable for this reason.

“If this trend continues unabated, future human generations may only be able to access the entirety of ancestral genetic diversity of chickens in the form of museum specimens,” Rheindt says, which could hamper chicken breeding efforts using the wild fowl genes.

Some countries such as Singapore, Rheindt says, have started managing jungle fowl populations to reduce interbreeding with chickens.

Procrastination may harm your health. Here’s what you can do

The worst procrastinators probably won’t be able to read this story. It’ll remind them of what they’re trying to avoid, psychologist Piers Steel says.

Maybe they’re dragging their feet going to the gym. Maybe they haven’t gotten around to their New Year’s resolutions. Maybe they’re waiting just one more day to study for that test.

Procrastination is “putting off to later what you know you should be doing now,” even if you’ll be worse off, says Steel, of the University of Calgary in Canada. But all those tasks pushed to tomorrow seem to wedge themselves into the mind — and it may be harming people’s health.
In a study of thousands of university students, scientists linked procrastination to a panoply of poor outcomes, including depression, anxiety and even disabling arm pain. “I was surprised when I saw that one,” says Fred Johansson, a clinical psychologist at Sophiahemmet University in Stockholm. His team reported the results January 4 in JAMA Network Open.

The study is one of the largest yet to tackle procrastination’s ties to health. Its results echo findings from earlier studies that have gone largely ignored, says Fuschia Sirois, a behavioral scientist at Durham University in England, who was not involved with the new research.

For years, scientists didn’t seem to view procrastination as something serious, she says. The new study could change that. “It’s that kind of big splash that’s … going to get attention,” Sirois says. “I’m hoping that it will raise awareness of the physical health consequences of procrastination.”

Procrastinating may be bad for the mind and body
Whether procrastination harms health can seem like a chicken-and-egg situation.

It can be hard to tell if certain health problems make people more likely to procrastinate — or the other way around, Johansson says. (It may be a bit of both.) And controlled experiments on procrastination aren’t easy to do: You can’t just tell a study participant to become a procrastinator and wait and see if their health changes, he says.
Many previous studies have relied on self-reported surveys taken at a single time point. But a snapshot of someone makes it tricky to untangle cause and effect. Instead, in the new study, about 3,500 students were followed over nine months, so researchers could track whether procrastinating students later developed health issues.

On average, these students tended to fare worse over time than their prompter peers. They were slightly more stressed, anxious, depressed and sleep-deprived, among other issues, Johansson and colleagues found. “People who score higher on procrastination to begin with … are at greater risk of developing both physical and psychological problems later on,” says study coauthor Alexander Rozental, a clinical psychologist at Uppsala University in Sweden. “There is a relationship between procrastination at one time point and having these negative outcomes at the later point.”

The study was observational, so the team can’t say for sure that procrastination causes poor health. But results from other researchers also seem to point in this direction. A 2021 study tied procrastinating at bedtime to depression. And a 2015 study from Sirois’ lab linked procrastinating to poor heart health.

Stress may be to blame for procrastination’s ill effects, data from Sirois’ lab and other studies suggest. She thinks that the effects of chronic procrastinating could build up over time. And though procrastination alone may not cause disease, Sirois says, it could be “one extra factor that can tip the scales.”

No, procrastinators are not lazy
Some 20 percent of adults are estimated to be chronic procrastinators. Everyone might put off a task or two, but chronic procrastinators make it their lifestyle, says Joseph Ferrari, a psychologist at DePaul University in Chicago, who has been studying procrastination for decades. “They do it at home, at school, at work and in their relationships.” These are the people, he says, who “you know are going to RSVP late.”

Though procrastinators may think they perform better under pressure, Ferrari has reported the opposite. They actually worked more slowly and made more errors than non-procrastinators, his experiments have shown. And when deadlines are slippery, procrastinators tend to let their work slide, Steel’s team reported last year in Frontiers in Psychology.

For years, researchers have focused on the personalities of people who procrastinate. Findings vary, but some scientists suggest procrastinators may be impulsive, worriers and have trouble regulating their emotions. One thing procrastinators are not, Ferrari emphasizes, is lazy. They’re actually “very busy doing other things than what they’re supposed to be doing,” he says.

In fact, Rozental adds, most research today suggests procrastination is a behavioral pattern.

And if procrastination is a behavior, he says, that means it’s something you can change, regardless of whether you’re impulsive.

Why procrastinators should be kind to themselves
When people put off a tough task, they feel good — in the moment.
Procrastinating is a way to sidestep the negative emotions linked to the task, Sirois says. “We’re sort of hardwired to avoid anything painful or difficult,” she says. “When you procrastinate, you get immediate relief.” A backdrop of stressful circumstances — say, a worldwide pandemic — can strain people’s ability to cope, making procrastinating even easier. But the relief it provides is only temporary, and many seek out ways to stop dawdling.

Researchers have experimented with procrastination treatments that run the gamut from the logistical to the psychological. What works best is still under investigation. Some scientists have reported success with time-management interventions. But the evidence for that “is all over the map,” Sirois says. That’s because “poor time management is a symptom not a cause of procrastination,” she adds.

For some procrastinators, seemingly obvious tips can work. In his clinical practice, Rozental advises students to simply put down their smartphones. Silencing notifications or studying in the library rather than at home can quash distractions and keep people on task. But that won’t be enough for many people, he says.

Hard-core procrastinators may benefit from cognitive behavioral therapy. In a 2018 review of procrastination treatments, Rozental found that this type of therapy, which involves managing thoughts and emotions and trying to change behavior, seemed to be the most helpful. Still, not many studies have examined treatments, and there’s room for improvement, he says.

Sirois also favors an emotion-centered approach. Procrastinators can fall into a shame spiral where they feel uneasy about a task, put the task off, feel ashamed for putting it off and then feel even worse than when they started. People need to short-circuit that loop, she says. Self-forgiveness may help, scientists suggested in one 2020 study. So could mindfulness training.

In a small trial of university students, eight weekly mindfulness sessions reduced procrastination, Sirois and colleagues reported in the January Learning and Individual Differences. Students practiced focusing on the body, meditating during unpleasant activities and discussed the best way to take care of themselves. A little self-compassion may snap people out of their spiral, Sirois says.

“You made a mistake and procrastinated. It’s not the end of the world,” she says. “What can you do to move forward?”

College Football Playoff rankings: Who are the top four teams in fourth CFP poll of 2021?

Two more top-10 teams in contention for the College Football Playoff lost on Saturday, creating yet more work for the selection committee. Well, sort of.

While the committee was forced to reshuffle the rankings after the losses of No. 3 Oregon (38-7 to No. 23 Utah) and No. 7 Michigan State (56-7 to No. 4 Ohio State), those outcomes actually created a more streamlined top 25 in the final weeks of the season.
The selection committee no longer has to explain why No. 6 Michigan ranked ahead of Michigan State, despite the Spartans' head-to-head victory over the Wolverines. Nor do they need to worry about where to rank Oregon, which beat Ohio State in Week 2, well before the Buckeyes' resurgence. The only actual problem created from Saturday's slate of games wasn't even a problem at all: Where to rank Alabama in relation to Ohio State.

The committee chose to push the Buckeyes ahead of the Crimson Tide in the latest rankings. That decision ultimately won't matter, considering Alabama must face No. 1 Georgia in the SEC championship game. A win there would give Nick Saban and Co. the top overall seed. A loss would eliminate the Tide from championship contention.

The committee will pay close attention to "The Game" and Bedlam in Week 13, two rivalry games that feature 10-1 opponents in Ohio State, Michigan, Oklahoma and Oklahoma State. That will further clear up the playoff picture, the final rankings for which are quickly approaching.

With that, here are the top 25 teams in the latest CFP rankings:
College Football Playoff rankings 2021
Who are the top four CFP teams of fourth CFP poll of 2021?
Ranking Team Record
1 Georgia 11-0
2 Ohio State 10-1
3 Alabama 10-1
4 Cincinnati 11-0
Who are the first two teams out of fourth CFP poll of 2021?
Ranking Team Record
5 Michigan 10-1
6 Notre Dame 10-1
CFP top 25 rankings from fourth CFP poll of 2021
Rank Team Record
1 Georgia 11-0
2 Ohio State 10-1
3 Alabama 10-1
4 Cincinnati 11-0
5 Michigan 10-1
6 Notre Dame 10-1
7 Oklahoma State 10-1
8 Baylor 9-2
9 Ole Miss 9-2
10 Oklahoma 10-1
11 Oregon 9-2
12 Michigan State 9-2
13 BYU 9-2
14 Wisconsin 8-3
15 Texas A&M 8-3
16 Iowa 9-2
17 Pittsburgh 9-2
18 Wake Forest 9-2
19 Utah 8-3
20 NC State 8-3
21 San Diego State 10-1
22 UTSA 11-0
23 Clemson 8-3
24 Houston 10-1
25 Arkansas 7-4

Steelers vs. Chargers final score, results: Austin Ekeler, Mike Williams power Chargers to late win over Steelers

The Chargers got outscored 27-14 in the fourth quarter on Sunday as Pittsburgh mounted a late comeback, but ultimately it wasn't enough for the Steelers, as Los Angeles won 41-37 after Justin Herbert hit Mike Williams for a 53-yard touchdown with 2:09 left to ice the game.

Herbert, along with running back Austin Ekeler out of the backfield, both did a bit of everything on offense. Herbert threw for 382 yards and three touchdowns while running for another 90. Ekeler, meanwhile, tallied four touchdowns — two rushing and two receiving — as he totaled 115 total yards.
The Chargers were 7-of-12 on third down, averaged 7.7 yards per play and amassed 533 yards of total offense. But it was two key plays late in the fourth quarter — a blocked punt and an interception by Justin Herbert — that allowed the Steelers to make a late comeback and even take the late lead for a short time.

Pittsburgh's offense flowed through Ben Roethlisberger, who turned in a three touchdown game as the ground game was sporadic at best, with Pittsburgh averaging just 3.1 yards per carry. Star rookie running back Najee Harris also missed much of the fourth quarter after being evaluated for a concussion. He was ultimately cleared to return on what wound up being Pittsburgh's final drive.

The win for Los Angeles improves its record to 6-4 and snaps a two-game home losing streak. They're now tied with Kansas City atop the AFC West with a game at Denver looming. Pittsburgh's loss drops it to 5-4-1, the Steelers' first loss since Oct. 3. They travel to Cincinnati next week to take on their fellow AFC North foes the Bengals.
Sporting News is tracked the live score, updates and highlights from 'Sunday Night Football.' Below is complete coverage.
Steelers vs. Chargers score
Q1 Q2 Q3 Q4 F
Steelers 3 7 0 27 37
Chargers 7 10 10 14 41
Steelers vs. Chargers updates, highlights
Final: Chargers 41, Steelers 37
11:35 p.m.: It's now fourth-and-32 from the 3 and the Steelers turn it over on downs and the Chargers take over with 1:15 left and will kneel it out here to end the game.

11:33 p.m.: Roethlisberger is dropped for 11 yards on second down after Joey Bosa gets the sack. Third-and-29 for the Steelers from their own 6.

11:31 p.m.: Roethlisberger is sacked on first down to bring up second-and-18 and the two-minute warning.

11:31 p.m.: Najee Harris clears concussion protocols and is back on the field for the Steelers for this drive. They start at their 25 with 2:09 left.

11:28 p.m.: TOUCHDOWN CHARGERS. Herbert hits Mike Williams for 53 yards and a score, Williams' first in a month. Chargers 41, Steelers 37 with 2:09 left as Pittsburgh needs a touchdown to win it with just one timeout left.
11:25 p.m.: FIELD GOAL STEELERS. The Steelers retake the lead as Boswell nails the 45-yarder with 3:24 left as Pittsburgh has come back from down 17 to tie it up. Pittsburgh 37, Los Angeles 34 with 3:24 remaining.

11:24 p.m.: Roethlisberger's pass falls incomplete and it brings up fourth-and-3 with Boswell slated to come on and kick the 45-yard field goal.

11:23 p.m.: The Steelers call their second timeout with 3:34 left. Third-and-3 from the 27 for the Steelers.

11:21 p.m.: Staley's gamble doesn't pay off as Ekeler is stuffed at the line. The Chargers turn it over on downs and Pittsburgh takes over at the LA 34.
11:20 p.m.: On third-and-14, Herbert to Jared Cook for 13 yards and Brandon Staley keeps the offense on the field on fourth-and-inches.

11:19 p.m.: Following the touchdown, it's almost immediately third-and-14 after Herbert is sacked. Pittsburgh calls its first timeout.

11:16 p.m.: TOUCHDOWN STEELERS. Roethlisberger hits Pat Freiermuth from 5 yards out on second-and-goal to tie it up with 4:23 left. Steelers 34, Chargers 34 with just over four minutes remaining.
11:15 p.m.: LA's Joey Bosa gets hit for a roughing the passer call and it sets up first-and-goal for the Steelers from the 5.

11:13 p.m.: INTERCEPTION STEELERS. Justin Herbert's pass is tipped but picked off and returned to the 11 yard line. First-and-10 for the Steelers who are looking to tie it up.
11:09 p.m.: TOUCHDOWN STEELERS. The Steelers make it a one-score game with 4:49 left after Roethlisberger finds Ebron again. Chargers 34, Steelers 27.
11:07 p.m.: Roethlisberger hits Ebron again for 9 yards and the Steelers are inside the red zone and showing signs of late life.

11:06 p.m.: Diontae Johnson hauls it in for 32 yards on the catch-and-run to put the Steelers at the LA 27 following the third-and-5.

11:05 p.m.: Harris heads to medical tent as It's now third-and-5 following the incompletion. 6:40 remaining in the game with Pittsburgh down two scores.

11:02 p.m.: On the first down play, Roethlisberger completes it to Harris for 5 yards, but Harris is down injured on the play. It'll be second-and-5 from Pittsburgh's own 41.
10:55 p.m.: TOUCHDOWN CHARGERS. Austin Ekeler notches his fourth touchdown of the game and has two rushing and two receiving touchdowns apiece. Now a two-score game with 8:38 left. Chargers 34, Steelers 20.
10:53 p.m.: Herbert's impressive ground game continues. He's up to 93 yards rushing after a 36 yard run on third-and-5. Tack on an unneccessary roughness penalty and it's first-and-goal from the 4.

10:47 p.m.: TOUCHDOWN STEELERS. This time the Steelers have no problem punching it in from short yardage as Najee Harris leaps over the pile for the score. Chargers 27, Steelers 20 with 11:35 left in the game.
10:44 p.m.: The Steelers are quickly looking at fourth-and-goal from the 5 and it's batted down but there's a penalty in the endzone for defensive pass interference. Now first-and-goal from the 1 for Pittsburgh.

10:40 p.m.: The Chargers punt It away from their 32 and it's blocked as the ball rolls out of bounds at the 3 yard line. First-and-goal for the Steelers upcoming.
10:34 p.m.: FIELD GOAL STEELERS. Boswell splits the uprights again, this time from 36 yards out. Chargers 27, Steelers 13 with 14:10 left in the game.

10:33 p.m.: It's third down again for the Steelers, this time from the Chargers' 20 but the pass gets batted away. The field goal unit comes out for Mike Tomlin.

End third quarter: Chargers 27, Steelers 10
10:28 p.m.: The Steelers are looking to convert on third down following the field goal and they do as Roethlisberger finds Najee Harris out of the backfield. Now first-and-10 from the Chargers 25 as Roethlisberger. hits Eric Ebron for 1 yard to end the third quarter.

10:22 p.m.: FIELD GOAL CHARGERS. Hopkins nails the 41-yarder and Los Angeles increases its lead with 3:40 left in the quarter. Chargers 27, Steelers 10,

10:21 p.m.: It's now fourth-and-8 and the Chargers move up 5 yards after the Steelers jump offsides as Hopkins lines up for a 41-yarder.

10:20 p.m.: It's now third-and-13 from the Steelers 28 but the Chargers can't convert. Brandon Staley brings out the field goal unit.

10:17 p.m.: Herbert takes off and runs again, this time on third down and he converts. The Chargers are 5-for-6 on third down so far and Herbert has five carries for 57 yards and is the team's leading rusher.

10:15 p.m.: The Chargers are quickly near midfield to the their own 42 where they'll be faced with first-and-20 following a holding penalty.

10:09 p.m.: The Steelers go three-and-out on their first drive to open the quarter. They punt it away and the Chargers take over at their 26.

10:04 p.m.: TOUCHDOWN CHARGERS. Austin Ekeler's monster day continues. He peels off a 12-yard run and then hauls in a 17-yard touchdown pass. It's his third touchdown of the game. Chargers 24, Steelers 10 with just under 12 minutes left in the third.
10:03 p.m.: Herbert goes to Allen again for 14 yards and the Chargers are in the red zone.

10:01 p.m.: This time Herbert has no problem hitting Allen. The two connect for 30 yards for an easy third-down conversion. Chargers now on the Steelers 43.

9:59 p.m.: It's quickly third-and-13 to open the second half as Herbert's pass to Keenan Allen falls short.

9:57 p.m.: The Chargers will receive the second half kick and take over at their 26 but there's a flag on the play. The penalty goes against the Steelers and the Chargers move up 5 yards to their own 31.

Halftime: Chargers 17, Steelers 10
9:41 p.m.: FIELD GOAL CHARGERS. Dustin Hopkins nails a 30-yarder with two seconds left on the clock to give the Chargers a touchdown lead heading into halftime. Chargers 17, Steelers 10.

9:35 p.m.: The Chargers have been marching to close out the first half following the touchdown. Looking at first-and-10 from their own 41 with 27 seconds left.

9:25 p.m.: TOUCHDOWN STEELERS. Roethlisberger throws up a floater that hangs in the air and he finds Johnson again in the back of the end zone. Chargers 14, Steelers 10 with 1:09 left in the first half.
9:24 p.m.: Roethlisberger hits Diontae Johnson for 9 yards to the LA 10. Steelers in a position to score before the half.

9:23 p.m.: Following the touchdown, Roethlisberger executes a nice throw and helps the Steelers march down the field.
9:14 p.m.: TOUCHDOWN CHARGERS. It's Austin Ekeler again, and the Chargers extend their lead. Chargers 14, Steelers 3 with 3:42 left in the first half.
9:12 p.m.: Another 18-yard run for Herbert followed by an 18-yard pass and it's now second-and-goal from the Pittsburgh 10 for LA.
9:09 p.m.: The Chargers are looking at third-and-6 from their own 28 and Herbert scrambles and keeps it for 18 yards to the LA 46. Nearing midfield.

9:06 p.m.: Ekeler takes it for 10 yards and a first down as the Chargers now have a more manageable field.

9:03 p.m.: The Steelers go 73 yards on 12 plays but turn it over on downs at the Chargers' 2 yard line. That's where LA takes over to begin its next drive.

9:00 p.m.: Roethlisberger hits Chase Claypool for 37 yards to the LA 5. Steelers in prime position to retake the lead here early in the second.
8:59 p.m.: The second quarter starts with a 3 yard run and a 5 yard run. Now third-and-2 from the LA 44 for the Steelers.

End first quarter: Chargers 7, Steelers 3
8:53 p.m.: The Steelers' drive following the touchdown is three plays, all of them to Najee Harris. Now third-and-6 from the Steelers' 40 for Pittsburgh.

8:47 p.m.: TOUCHDOWN CHARGERS. No doubt about that one as Austin Ekeler runs straight ahead and barrels his way through for the score. Caps off a 12 play, 73-yard drive that chewed nearly six minutes of clock. Chargers 7, Steelers 3 with 2:09 left in the first.
8:46 p.m.: The Chargers punch it in but get hit for illegal formation. Drives them back 5 yards to the Pittsburgh 6 and a replay of first down.

8:44 p.m.: On third-and-3 from the Pittsburgh 21, Justin Herbert hits Williams again, this time for 17 yards. Brings up first-and-goal from the 4.

8:40 p.m.: Los Angeles converts on third-and-14 after hitting Mike Williams for 22 yards. That's followed up by 5-yard catch by Jared Cook and an 11-yard grab by Keenan Allen. Chargers across midfield to the Steelers' 39.

8:38 p.m.: The Chargers open their game at their own 27.

8:36 p.m.: FIELD GOAL STEELERS. Boswell nails the the 36 yarder and the game's first points are on the board. Steelers 3, Chargers 0 with 8:33 left in the game.

8:34 p.m.: The Steelers go three-and-out in the red zone and will send Chris Boswell on to kick.

8:32 p.m.: After a gain of 16 yards and two defensive penalties on the Chargers, the Steelers are officially in the red zone for the first time tonight. Second-and-5 from the 18 upcoming.

8:28 p.m.: Roethlisberger hits tight end Pat Freiermuth to convert on third down once again. This time it goes for 4 yards and the Steelers are nearing midfield at their own 49.

8:27 p.m.: The game's first penalty is against Los Angeles' Joey Bosa, who gets hit for a neutral zone infraction Second-and-5 upcoming for the Steelers.

8:24 p.m.: Ben Roethlisberger's first pass of the game is complete to Chase Claypool on third down and the Steelers convert. Gain of 8 on the play.

8:23 pm.: The Steelers start the game with the ball at their own 25.