Tag Archives: study

Physicists Say We Were Completely Wrong About How Gravity Works

Posted on by

A new theoretical proposal suggests scrapping nearly everything we think we know about gravity in order to understand the universe.

A theoretical proposal published in the journal Reports on Progress in Physics is making some bold claims about our previous understanding of quantum physics. Mainly, that we were wrong.

The proposed theory grapples with the fact that quantum mechanics (basically modern physics) and general relativity (Einstein's theory of gravity) both describe the universe perfectly, but are mathematically incompatible with each other.

To make them work, the proposal suggests scrapping almost everything we think we know about gravity, as Live Science explains. Instead, the authors touch up the theory to match known and observable physics, something they call unified gravity.

Although quantum field theory — the framework explaining how subatomic particles behave — is one of the most accurate theoretical concepts of all time according to theoretical physicist David Tong, it still leaves out classical gravity, which we know as the bending of space-time.

Instead, unified gravity assumes gravity is managed by four connected components that perfectly interact with one another, a tweak that allows general relativity to respectfully play ball with quantum mechanics without sneaking off into other dimensions. In short, a model that physicists could actually test in real life.

"The main advantages or differences in comparison with many other quantum gravity theories are that our theory does not need extra dimensions that do not yet have direct experimental support," co-author Jukka Tulkki told Live Science.

The discrepancy between the theories of physics and gravity has a long history. To get around it, some have proposed that the universe may be made of tiny chunks. Others, like the string theorists of the late 1960s and 70s, argued for a one-dimensional framework of particle physics.

String theory ballooned into five separate theories back in the 80s, and has since come under increasing scrutiny as its proponents struggle to make any predictions we can actually prove.

"Are you chasing a ghost or is the collection of you just too stupid to figure this out?" as Neil deGrasse Tyson quipped back in 2011. This new model is an attempt to skip all that.

Going forward, there's a lot of work to be done before we know if the budding theory bears fruit.

"Given the current pace of theoretical and observational advancements, it could take a few decades to make the first experimental breakthroughs that give us direct evidence of quantum gravity effects," Mikko Partanen, the study's other author told Live Science. "Indirect evidence through advanced observations could be obtained earlier."

Still, it offers physicists a bold new trail to blaze in the long-running search to unite quantum physics with the theory of gravity — the possibility of unraveling the tangled secrets of the known universe.

More on Physics: Physicist Says He's Identified a Clue That We're Living in a Computer Simulation

The post Physicists Say We Were Completely Wrong About How Gravity Works appeared first on Futurism.

Read the original here:
Physicists Say We Were Completely Wrong About How Gravity Works

Scientists Successfully Grow Human Tooth in Lab, With Aim of Implanting in Humans

Posted on by

Scientists at King's College London, UK, say they've successfully grown a human tooth in a lab for the first time.

Scientists at King's College London say they've successfully grown a human tooth in a lab for the first time.

As detailed in a paper published in the journal ACS Macro Letters, the team said it uncovered a potential way to regrow teeth in humans as a natural alternative to conventional dental fillings and implants, research they say could "revolutionize dental care."

The researchers claim they've developed a new type of material that enables cells to communicate with one another, essentially allowing one cell to "tell" another to differentiate itself into a new tooth cell.

In other words, it mimics the way teeth grow naturally, an ability we lose as we grow older.

"We developed this material in collaboration with Imperial College to replicate the environment around the cells in the body, known as the matrix," explained author and King’s College London PhD student Xuechen Zhang in a statement. "This meant that when we introduced the cultured cells, they were able to send signals to each other to start the tooth formation process."

"Previous attempts had failed, as all the signals were sent in one go," he added. "This new material releases signals slowly over time, replicating what happens in the body."

However, porting the discovery from the lab, and transforming it into a viable treatment will require years of research.

"We have different ideas to put the teeth inside the mouth," Xuechen said."We could transplant the young tooth cells at the location of the missing tooth and let them grow inside mouth. Alternatively, we could create the whole tooth in the lab before placing it in the patient’s mouth."

While we're still some ways away from applying the findings to human subjects, in theory the approach could have some significant advantages over conventional treatments like fillings and implants.

"Fillings aren’t the best solution for repairing teeth," said Xuechen. "Over time, they will weaken tooth structure, have a limited lifespan, and can lead to further decay or sensitivity."

"Implants require invasive surgery and good combination of implants and alveolar bone," he added. "Both solutions are artificial and don’t fully restore natural tooth function, potentially leading to long-term complications."

The new approach, in contrast, could offer a better long-term solution.

"Lab-grown teeth would naturally regenerate, integrating into the jaw as real teeth," Xuechen explained. "They would be stronger, longer lasting, and free from rejection risks, offering a more durable and biologically compatible solution than fillings or implants."

While nobody knows whether lab-grown teeth will become a viable dental treatment, experts remain optimistic.

"This new technology of regrowing teeth is very exciting and could be a game-changer for dentists," King's College clinical lecturer in prosthodontics Saoirse O'Toole, who was not involved in the study, told the BBC. "Will it come in my lifetime of practice? Possibly. In my children's dental lifetimes? Maybe. But in my children's children's lifetimes, hopefully."

More on lab teeth: Scientists Grow Living "Replacement Teeth" for Dental Implants

The post Scientists Successfully Grow Human Tooth in Lab, With Aim of Implanting in Humans appeared first on Futurism.

See original here:
Scientists Successfully Grow Human Tooth in Lab, With Aim of Implanting in Humans

Giving ADHD Drugs to Kids Has a Long-Term Side Effect That Might Change Their Minds About Taking It

Posted on by

ADHD drugs may have bizarre side effects for kids who take them while they're growing — and it's a tall order as to whether they're worth it.

As wildly overinvolved parents shell out to give their kids growth hormones to make them taller, some research suggests that putting them on drugs for attention deficit hyperactivity disorder (ADHD) may have the opposite effect.

As the New York Times reports, the scientists behind the Multimodal Treatment of Attention Deficit Hyperactivity Disorder Study, or MTA Study for short, weren't exactly looking for physiological changes in their subjects: a cohort of 579 kids with ADHD, some of whom were given methyphenidate (better known as Ritalin), counseling, a mix of the two, or neither.

Beginning in 1994, researchers across the country began tracking outcomes of children who were seven to ten years old at the start of the study. After 36 months, the researchers realized something odd: that the children who had been given the popular stimulant seemed to be growing more slowly than their non-medicated counterparts.

The researchers presumed, per their retelling to the NYT, that this "height gap" would close in adolescence. When they followed up with them nine years after the study began, however, the medicated cohort was still 1.6 inches, on average, shorter than the kids who didn't take Ritalin.

On a certain level, the concern is very shallow. There's nothing wrong with being short, and if a drug can help with a myriad of other symptoms, maybe the risk is worth it.

But that's not the only controversy around prescribing ADHD drugs to kids. The MTA study's biggest takeaway was, troublingly, that the attention benefits of Ritalin seemed to cease after the first year, and that there were no apparent benefits to academic performance.

And even on top of that, the "height suppression" side effect was also enough to give the researchers pause.

In 2017, the MTA study scientists published a follow-up looking into the height gap that tracked the original cohort until they were 25. That height gap remained, per the study, into adulthood. And the findings countered bold academic assertions from just a few years prior claiming that any height suppression from ADHD meds in children would, as the researchers initially presumed, ultimately be undone in adolescence.

Years later, another group of scientists reviewed 18 childhood Ritalin studies and found, similarly to the MTA researchers, that the drug can indeed "result in reduction in height and weight" — though their opinion was that the size of the effect is negligible when compared to the purported benefits of these drugs.

To this day, researchers can't agree as to whether or not stimulants can cause height suppression in children, primarily because the mechanism behind the demonstrated effect remains unknown.

Speaking to the website Health Central in 2022, childhood psychiatrist and MTA study co-author Laurence Greenhill of the University of California, San Francisco suggested that amphetamines' well-known propensity to suppress appetite could be behind the growth differences.

"There could be some lack of nutrition going on that explains this," Greenhill told the website.

"However, the kids aren't malnourished," he countered. "They're just growing a little more slowly."

If Ritalin or other stimulants help a child significantly, such a minor height disparity would be worthwhile. But with some of the original MTA study authors now questioning how effective these medical interventions really are, it may behoove parents to think before they put their kids on these pills.

More on ADHD meds: To Fill Your Adderall Prescription Amid Shortage, Try Getting It Filled on This Particular Day of the Month

The post Giving ADHD Drugs to Kids Has a Long-Term Side Effect That Might Change Their Minds About Taking It appeared first on Futurism.

See the original post:
Giving ADHD Drugs to Kids Has a Long-Term Side Effect That Might Change Their Minds About Taking It

Scientists Say Skeletons Show Ancient Humans With Huge Heads

Posted on by

Scientists suggest a

Big Brain Time

Scientists are suggesting that a "large-headed" group of extinct humans once lived during the same time as homo sapiens — that's us, of course — hundreds of millennia ago in what's now modern-day China.

As detailed in a paper published in the journal Nature Communications last month, University of Hawaii at Manoa anthropologist Christopher Bae and Chinese Academy of Sciences paleontologist Xiujie Wu are proposing the existence of a new group of humans called the Juluren, which roughly translates to "big heads."

Many of the proposed group's attributes, based on bone fragments collected across modern-day China, are currently ascribed to Denisovans, a subspecies of archaic humans who lived across Asia from 285,000 to 25,000 years ago.

However, Wu and Bae argue that some of these fossils' features should be assigned to their own species.

"Collectively, these fossils represent a new form of large-brained hominin," they wrote in the study.

Head Hunters

The species, which would've lived from around 300,000 years ago until about 50,000 years ago across eastern Asia, likely hunted wild horses in small groups. They also appeared to make stone tools and used animal hides for survival.

Wu and Bae are hoping to fill in the gaps in our current knowledge of extinct human subspecies by refining how we refer to these disparate groups today.

"This study clarifies a hominin fossil record that has tended to include anything that cannot easily be assigned to Homo erectus, Homo neanderthalensis or Homo sapiens," Bae said in a statement. "Although we started this project several years ago, we did not expect being able to propose a new hominin (human ancestor) species and then to be able to organize the hominin fossils from Asia into different groups."

All told, the research suggests a far more complex and nuanced picture of the dispersal of human groups over hundreds of thousands of years.

"I see the name Juluren not as a replacement for Denisovan, but as a way of referring to a particular group of fossils and their possible place in the network of ancient groups," paleoanthropologist John Hawks, who was not involved in the research, wrote in a blog post about the study.

"I think the record is more expansive than most specialists have been assuming," he added. "Calling all these groups by the same name makes sense only as a contrast to recent humans, not as a description of their populations across space and time."

Wu and Bae would tend to agree.

"If anything, the eastern Asian record is prompting us to recognize just how complex human evolution is more generally and really forcing us to revise and rethink our interpretations of various evolutionary models to better match the growing fossil record," they wrote in their study.

More on homo sapiens: Scientists Find Structure From Before Homo Sapiens Existed

The post Scientists Say Skeletons Show Ancient Humans With Huge Heads appeared first on Futurism.

More here:
Scientists Say Skeletons Show Ancient Humans With Huge Heads

When They Took Fluoride Out of the Water Like RFK Jr. Wants to Do Everywhere, People’s Teeth Started Rotting Out of Their Heads

Posted on by

An Alaskan city removed fluoride from its drinking water like RFK wants to do for the whole country — and tooth decay surged.

Our next potential leader of US health policy, Robert F. Kennedy Jr, wants to ban adding fluoride to public drinking water — a practice that experts agree has remarkably elevated teeth health for millions of Americans at little cost.

In a country where many people don't have access to dental care, a widespread crackdown on this naturally occurring mineral could be a disaster. To see how, we turn to the sobering case of Juneau, a city in Alaska that voted to stop fluoridating its water in 2007, citing many of the same fears that RFK touts today.

In a 2018 study published in the journal BMC Oral Health, researchers examined the dental records of adolescents in the Alaska community who sought Medicaid dental care in the years surrounding either side of the ban.

They divided them into two treatment groups: a 2003 group, when public drinking water had optimal levels of fluoride, and a 2012 group, well after the fluoride ban.

The results were damning. On average, the 2012 group had a significantly higher number of cavity-related procedures for adolescents than the 2003 group. Similarly, the odds of someone 18 years-old or younger undergoing the same type of procedure was 25 percent higher in 2012.

Children born after the fluoride ban were the hardest hit age group, receiving not only the most tooth decay treatments, but also having the most expensive treatments on average.

Additionally on the economic side of things, the researchers found that dental care costs for adolescents soared by 73 percent as a result of the fluoride policy, even after adjusting for inflation. In sum, it seems clear cut that removing fluoride caused tooth rot to surge — and with it, medical costs.

Today, nearly three-quarters of the US population has access to fluoridated water, reducing tooth decay in children and adults by an estimated 25 percent. The US Centers for Disease Control has hailed fluoridation as one of the top ten greatest public health interventions in history.

So why does RFK, who was nominated by president-elect Donald Trump to be the head of the Department of Health and Human Services, want to ban it? Well, according to him and other critics, fluoride is dangerous "industrial waste" that's associated with everything from IQ loss to cancer.

While fluoride does have its complications, RFK's criticisms haven't been proven or are overblown — and most of fluoridation's drawbacks come from doses that are extremely high compared to the amount added to public water.

According to Scientific American, at three times the recommended level in water, fluoride can cause a condition called dental fluorosis, which damages — typically cosmetically — the developing teeth of young children. It can also cause more serious and painful skeletal fluorosis, but that's exceedingly rare.

As far as the effects on a child's mental acuity goes, the evidence is highly disputed. A 2024 review conducted by the US National Toxicology Program linked high levels of fluoride to lower IQs in children — but the study only focused on the effects of fluoride at twice the recommended level in the US, and couldn't draw as strong a link at reasonable fluoride concentrations. It also failed to pass scientific review twice, and bypassed independent review on its most recent version, per SciAm.

In short, there's not nearly enough evidence yet to justify a nationwide ban on fluoridation — and plenty of evidence to show it'd be a bad idea.

More on RFK: If You Take Adderall, RFK Jr. Should Probably Make You Quite Nervous

The post When They Took Fluoride Out of the Water Like RFK Jr. Wants to Do Everywhere, People's Teeth Started Rotting Out of Their Heads appeared first on Futurism.

Read more from the original source:
When They Took Fluoride Out of the Water Like RFK Jr. Wants to Do Everywhere, People's Teeth Started Rotting Out of Their Heads

Scientists Gene Hack Bacteria That Breaks Down Plastic Waste

Posted on by

The scientists edited to the bacteria to prove which enzyme it used to degrade PET plastics into bioavailable carbon.

Bottom Feeders

We may have a way of literally eating away at our planet's pollution crisis.

As part of a new study published in the journal Environmental Science and Technology, researchers have shed additional light on a possibly game-changing bacteria that grows on common polyethylene terephthalate (PET) plastics, confirming that it can break down and eat the polymers that make up the waste.

Scientists have long been interested in the plastic-decomposing abilities of the bacteria, Comamonas testosteroni. But this is the first time that the mechanisms behind that process have been fully documented, according to study senior author Ludmilla Aristilde.

"The machinery in environmental microbes is still a largely untapped potential for uncovering sustainable solutions we can exploit," Aristilde, an associate professor of civil and environmental engineering at Northwestern University in Illinois, told The Washington Post.

Enzyme or Reason

To observe its plastic-devouring ability, the researchers isolated a bacterium sample, grew it on shards of PET plastics, and then used advanced microscopic imaging to look for changes inside the microbe, in the plastic, and in the surrounding water.

Later, they identified the specific enzyme that helped break down the plastic. To prove it was the one, they edited the genes of the bacteria so that it wouldn't secrete the enzyme and found that without it, the bacteria's plastic degrading abilities were markedly diminished.

That gene-hacking trick formed a full picture of what goes on. First, the bacteria more or less chews on the plastic to break it into microscopic particles. Then, they use the enzyme to degrade the tiny pieces into their monomer building blocks, which provide a bioavailable source of carbon.

"It is amazing that this bacterium can perform that entire process, and we identified a key enzyme responsible for breaking down the plastic materials," Aristilde said in a statement about the work. "This could be optimized and exploited to help get rid of plastics in the environment."

PET Project

PET plastics, which are often used in water bottles, account for 12 percent of global solid waste, the researchers said. It also accounts for up to 50 percent of the microplastics found in wastewater.

That happens to be the environment that C. testosteroni thrives in, opening up the possibility of tailoring the bacteria to clean up our sewage before it's dumped into the ocean, for example.

But we'll need to understand more about the bacteria before that can happen.

"There's a lot of different kinds of plastic, and there are just as many potential solutions to reducing the environmental harm of plastic pollution," Timothy Hollein, a professor of biology at Loyola University Chicago who was not involved with the study, told WaPo. "We're best positioned to pursue all options at the same time."

More on pollution: A Shocking Percentage of Our Brains Are Made of Microplastics, Scientists Find

The post Scientists Gene Hack Bacteria That Breaks Down Plastic Waste appeared first on Futurism.

Excerpt from:
Scientists Gene Hack Bacteria That Breaks Down Plastic Waste