Hawking Radiation Isn’t Just For Black Holes, Study Shows

Hawking Radiation Isn't Just For Black Holes, Study Shows

 

One of the most remarkable achievements in theoretical physics came in 1974, when Stephen Hawking demonstrated that black holes are not static, stable entities within spacetime, but rather must emit radiation and eventually decay. This radiation, known forever after as Hawking radiation, arises due to the combination of the facts that. Hawking radiation isn’t just for black holes, study shows

  • quantum fields permeate all of space,
  • including inside and outside a black hole’s event horizon,
  • that these fields are not static but exhibit quantum fluctuations,
  • and that those fields behave differently in regions where the curvature of spacetime is different.

E = mc²

When Hawking first put these facts together, his calculation showed that black holes can’t be stable with a constant mass, but will instead emit an omnidirectional amount of extremely low-temperature blackbody radiation. This radiation propagates away from the event horizon, and since real radiation carries energy, the only place where that energy can be taken from is from the mass of the black hole itself: via the classic equation E = mc², where the mass lost by the black hole has to balance the energy of the emitted radiation.

But in a delightful new paper, physicists Michael Wondrak, Walter van Suijlekom, and Heino Falcke have challenged the idea that an event horizon is necessary for this radiation. According to their new approach, this radiation arises solely because of the differences in the quantum vacuum of space dependent on its curvature, and therefore Hawking radiation should be emitted by all masses in the Universe, even those without event horizons. It’s a remarkable idea and one that’s been brewing for a long time. Let’s unpack why. Hawking Radiation Isn’t Just For Black Holes, Study Shows

 

Hawking Radiation Isn't Just For Black Holes, Study Shows
Hawking Radiation Isn’t Just For Black Holes, Study Shows

Visualization of QCD illustrates

A visualization of QCD illustrates how particle-antiparticle pairs pop out of the quantum vacuum for very small amounts of time as a consequence of Heisenberg uncertainty. The quantum vacuum is interesting because it demands that empty space itself isn’t so empty, but is filled with all the particles, antiparticles, and fields in various states that are demanded by the quantum field theory that describes our Universe. The particle-antiparticle pairs illustrated here, however, are only a calculational tool; they are not to be confused with real particles. Hawking radiation isn’t just for black holes, study shows

The particle-antiparticle pairs illustrated

There’s a very common misconception about how Hawking radiation works, put forth by none other than Hawking himself in his celebrated popular book, A Brief History of Time. The way Hawking told us to envision it:

  • the Universe is filled with particle-antiparticle pairs popping in-and-out of existence,
  • even in empty space, as a consequence of quantum field theory and the Heisenberg uncertainty principle,
  • that in uncurved space, these pairs always find one another and re-annihilate after a very small time interval,
  • but if an event horizon is present, one member of the pair can “fall in” while the other “escapes,”
  • leading to a situation where real particles (or antiparticles) are emitted with positive mass/energy from just outside the horizon itself,
  • whereas the paired member that falls into the event horizon must have “negative energy” that subtracts from the black hole’s total mass.

It’s a convenient picture, to be sure, but it’s a picture that even Hawking himself knew must be false. Despite the fact that, in his 1974 paper, he wrote:

“It should be emphasized that these pictures of the mechanism responsible for the thermal emission and area decrease are heuristic only and should not be taken too literally,”

He does, in fact, take it literally in his 1988 book that brought this idea to the general public.

 

Hawking Radiation Isn't Just For Black Holes, Study Shows
Hawking Radiation Isn’t Just For Black Holes, Study Shows

Brief History of Time

The reason you cannot take this picture literally is because the particle-antiparticle pairs that pop in-and-out of existence are not actual, real particles; they are what physicists call virtual particles: a calculational tool that we use that represents fluctuations in the underlying fields, but that are not “real” in the sense that we cannot interact with or measure them directly in any way.

If you did take this picture literally, you’d erroneously think that this Hawking radiation is composed of a mixture of particles and antiparticles; it is not. Instead, it’s just composed of extremely low-energy photons in a blackbody spectrum, as even the lightest set of massive particles known, the neutrinos and antineutrinos, are far too heavy for even a single one to be produced by the real black holes in our Universe.

Fundamental Properties of Quantum Fields

Instead, the actual explanation  although there are many legitimate ways to approach calculating the effect (including ways that do involve these virtual particle-antiparticle pairs) is that it is the difference in the quantum vacuum (i.e., the fundamental properties of quantum fields in empty space) between regions of space with different amounts of spatial curvature that leads to the production of this thermal, blackbody radiation that we call Hawking radiation. Hawking Radiation Isn’t Just For Black Holes, Study Shows

Hawking Radiation Isn't Just For Black Holes, Study Shows
Hawking Radiation Isn’t Just For Black Holes, Study Shows

 

The most common, and incorrect, explanation for how Hawking radiation arises is an analogy with particle-antiparticle pairs. If one member with negative energy falls into the black hole’s event horizon, while the other member with positive energy escapes, the black hole loses mass and outgoing radiation departs the black hole. This explanation has misinformed generations of physicists and came from Hawking himself. One of the errors inherent to this explanation is the notion that all of the Hawking radiation arises from the event horizon itself: it does not.

There are a few interesting points that arise, that have been known for many decades, as a consequence of the ways Hawking radiation actually works.

Interesting point #1:

The Hawking radiation itself cannot all originate from the event horizon of the black hole itself.

One of the fun things you can calculate, at any moment in time, is the density of the Hawking radiation that arises all throughout space. You can calculate the energy density as a function of distance from the black hole, and you can compare that to a calculation for what the expected energy density would be if the radiation all originated at the event horizon itself and then propagated outward in space.

Remarkably, those two calculations do not match up at all; in fact, most of the Hawking radiation that arises around the event horizon of the black hole originates within about 10-20 Schwarzschild radii (the radius from the singularity to the event horizon) of the event horizon, rather than at the event horizon itself. In fact, there are non-zero amounts of radiation that are emitted throughout all of space, even far away from the event horizon itself. The horizon itself may play a role that’s important in the generation of Hawking radiation, just as Unruh radiation ought to be generated owing to the presence of a cosmic horizon in our own Universe, but you cannot generate all of your Hawking radiation at the event horizon of a black hole and get predictions that are consistent with our theoretical calculations.

 

Hawking Radiation Isn't Just For Black Holes, Study Shows
Hawking Radiation Isn’t Just For Black Holes, Study Shows

It must be noted that it isn’t particles or antiparticles that are produced when black holes undergo Hawking radiation, but rather photons. One can calculate this using the tools of virtual particle-antiparticle pairs in curved space in the presence of an event horizon, but those virtual pairs should not be construed as being real particles, nor should all of the radiation be construed as arising from just barely outside the event horizon.

Interesting point #2:

More radiation gets emitted from more severely curved regions of space, implying that lower-mass black holes emit more Hawking radiation and decay faster than higher-mass ones.

This is a point that puzzles most people the first time they hear about it: the more massive your black hole is, the less severely curved your space will be just outside the black hole’s event horizon. Yes, the event horizon is always defined by that boundary where the escape velocity of a particle is either less than the speed of light (which is outside the event horizon) or greater than the speed of light (which defines inside the event horizon), and the size of this horizon is directly proportional to the black hole’s mass.

But the curvature of space is much greater near the event horizon of a smaller, low-mass black hole than it is near the event horizon of a larger, greater-mass black hole. In fact, if we look at the properties of the emitted Hawking radiation for black holes of different (realistic) masses, we find:

  • The temperature of the radiation is inversely proportional to the mass: ten times the mass means one-tenth the temperature.
  • The luminosity, or radiated power, of a black hole, is inversely proportional to the square of the black hole’s mass: ten times the mass means one-hundredth the luminosity.
  • And the evaporation time for a black hole, or how long it takes for a black hole to completely decay away into Hawking radiation, is directly proportional to the mass of the black hole cubed: a black hole that’s ten times as massive as another will persist for one thousand times as long.

 

Hawking Radiation Isn't Just For Black Holes, Study Shows
Hawking Radiation Isn’t Just For Black Holes, Study Shows

Although no light can escape from inside a black hole’s event horizon, the curved space outside of it results in a difference between the vacuum state at different points near the event horizon, leading to the emission of radiation via quantum processes. This is where Hawking radiation comes from, and for the lowest-mass black holes ever discovered, Hawking radiation will lead to their complete decay in ~10^68 years. For even the largest mass black holes, survival beyond 10^103 years or so is impossible due to this exact process. The higher mass your black hole is, the weaker Hawking radiation is and the longer it will take to evaporate.

Interesting point #3:

 The amount by which spacetime is curved at a given distance from a mass is completely independent of how dense that mass is, or whether it has an event horizon at all.

Here’s a fun question to consider. Imagine, if you will, that the Sun was magically, instantaneously replaced with an object that was the exact same mass as the Sun but whose physical size was either:

  • the size of the Sun itself (with a radius of about 700,000 km),
  • the size of a white dwarf (with a radius of about 7,000 km),
  • the size of a neutron star (with a radius of around 11 km),
  • or the size of a black hole (whose radius would be about 3 km).

Now, imagine you’re assigned the following task: to describe what the curvature of space is, and how it’s different, between these four separate examples.

The answer, quite remarkably, is that the only differences that arise are if you’re at a location that’s inside of the Sun itself. As long as you’re more than 700,000 km away from a solar mass object, then it doesn’t matter whether that object is a star, a white dwarf, a neutron star, a black hole, or any other object with or without an event horizon: its spacetime curvature and properties are the same.

 

Hawking Radiation Isn't Just For Black Holes, Study Shows
Hawking Radiation Isn’t Just For Black Holes, Study Shows

Although the amount that spacetime is curved and distorted depends on how dense the object in question is when you’re close to the object’s edge, the size and volume that the object occupies is unimportant far away from the mass itself. For a black hole, neutron star, white dwarf, or a star like our Sun, the spatial curvature is identical at sufficiently large radii. Hawking Radiation Isn’t Just For Black Holes, Study Shows

If you put these three points together, you might start wondering for yourself what many physicists have wondered for a very long time: does Hawking radiation only occur around black holes, or does it occur for all massive objects within spacetime?

Key Feature in Hawking’s Original Derivation

Although the event horizon was a key feature in Hawking’s original derivation of the radiation that now bears his name, there have been other derivations (sometimes in alternate numbers of dimensions) that have shown this radiation still exists in curved spacetime, irrespective of the presence or absence of such a horizon. That’s where the new paper that comes in is so interesting: the only role the event horizon plays is to serve as a boundary for where radiation can be “captured” from versus where it can “escape” from. The calculation is done in fully four-dimensional spacetime (with three space and one time dimension), and shares many important features with other approaches to calculating the presence and properties of Hawking radiation.

The boundary for what gets captured versus what escapes would still exist for any other example of a mass we chose:

  • it would be the event horizon for a black hole,
  • the surface of a neutron star for a neutron star,
  • the outermost layer of a white dwarf for a white dwarf,
  • or the photosphere of a star for a star.

Escape Fraction

In all cases, there would still be an escape fraction that depended on the mass and radius of the object in question; there’s nothing special about the presence or absence of an event horizon. The event horizon of a black hole has been considered an important factor in the generation of Hawking radiation around black holes in many previous studies, but a new one suggests that this radiation can still be generated outside of an event horizon even if the horizon itself does nothing more than forbid light from escaping from within it.

Hawking Radiation Isn't Just For Black Holes, Study Shows
Hawking Radiation Isn’t Just For Black Holes, Study Shows

Wondrak, van Suijlekom, and Falcke

There’s a very simple analogy to the approach that Wondrak, van Suijlekom, and Falcke take in their paper: to that of the Schwinger effect in electromagnetism. Way back in 1951, physicist Julian Schwinger one of the co-discoverers of quantum electrodynamics detailed how matter could be created from pure energy in the vacuum of space simply by creating a strong enough electric field. Whereas you can envision quantum field fluctuations however you like in the absence of an external field, applying a strong external field polarizes even the vacuum of space: separating positive from negative charges. If the field is strong enough, these virtual particles can become real, stealing energy from the underlying field to keep energy conserved.

Schwinger Effect, the Gravitational Analogue

Instead of an electric field, charged particles, and the Schwinger effect, the gravitational analogue is simply to use the background of curved spacetime for the electric field, to substitute an uncharged, massless scalar field for the charged particles: a simplistic analogue to stand-in for the photons that would be produced via Hawking radiation. Instead of the Schwinger effect, what they see is the production of new quanta in this curved spacetime, with a “production profile” that depends on the radius you are away from the event horizon. But note that there’s nothing special about the horizon itself: production occurs at all distances sufficiently far from the object itself.

Gravitational Pair Production and Black Hole Evaporation

 As calculated in the paper “Gravitational Pair Production and Black Hole Evaporation,” there is no emitted radiation from inside a black hole’s event horizon (less than “2” on the x-axis), but the radiation arises from an infinitely-extending region outside of the event horizon, peaking at 25% larger than the horizon itself but falling off slowly thereafter. The implication is that even massive objects without an event horizon, like stars, should emit some amount of Hawking radiation.
Credit: M.F. Wondrak et al., Phys. Rev. Lett. accepted, 2023

The key takeaway, assuming the paper’s analysis is valid (which of course requires independent confirmation), is that there is no “special role” played by the event horizon as far as the production of radiation (or any other types of particles) goes. Quite generally, if you have

  • a quantum field theory,
  • with creation and annihilation operators,
  • with some sort of tidal, differential forces acting on the field fluctuations (or virtual particles and antiparticles, if you prefer),
  • that will create an additional separative effect over what you’d expect in a uniform background of empty space,

then you can conclude that a fraction of the particles that are produced will escape, in a radius-dependent fashion, irrespective of the presence or absence of an event horizon. Hawking Radiation Isn’t Just For Black Holes, Study Shows

 

Hawking Radiation Isn't Just For Black Holes, Study Shows
Hawking Radiation Isn’t Just For Black Holes, Study Shows

Travel the Universe with astrophysicist Ethan Siegel. Subscribers will get the newsletter every Saturday. All aboard!

Theorized by Julian Schwinger

It’s perhaps important to note that this new work does not reproduce all of the known features of Hawking radiation exactly; it is only a simplistic model that stands in for a realistic black hole. Nevertheless, many of the lessons gleaned from this study, as well as from the toy model motivating it, may prove to be incredibly important for understanding not only how Hawking radiation works, but under what circumstances and conditions it gets generated by. It also sets the stage, just as has been already accomplished for the Schwinger effect, for condensed matter analogue systems to be constructed, where this effect may actually be quantifiable and observable.

 

Hawking Radiation Isn't Just For Black Holes, Study Shows
Hawking Radiation Isn’t Just For Black Holes, Study Shows

In theory, the Schwinger effect states that in the presence of strong enough electric fields, (charged) particles and their antiparticle counterparts will be ripped from the quantum vacuum, empty space itself, to become real. Theorized by Julian Schwinger in 1951, the predictions were validated in a tabletop experiment, using a quantum analogue system, for the first time.

Hawking Radiation Black Hole Decay

One of the things I greatly appreciate about this paper is that it corrects a big, widespread misconception: the idea that Hawking radiation is generated at the event horizon itself. Not only is this not true, but the horizon only serves as a “cutoff point” in the sense that no radiation generated inside of it can escape. Instead, there is a specific radial production profile for this radiation, where there’s a peak amount of radiation that is generated and escapes at about 125% of the event horizon’s radius, and then that radiation falls off and asymptotes to zero at greater radii, but there’s always some non-zero amount of production that can be predicted.

An interesting thing to think about is that, for black holes, there is no external energy reservoir to “draw” this energy from, and hence the energy for this radiation must come from the massive object at the center, itself. For a black hole, that means it must decay, leading to its eventual evaporation.

 

Hawking Radiation Isn't Just For Black Holes, Study Shows
Hawking Radiation Isn’t Just For Black Holes, Study Shows

The event horizon of a black hole is a spherical or spheroidal region from which nothing, not even light, can escape. But outside the event horizon, the black hole is predicted to emit radiation. Hawking’s 1974 work was the first to demonstrate this, and it was arguably his greatest scientific achievement. A new study now suggests that Hawking radiation may even be emitted in the absence of black holes, with profound implications for all stars and stellar remnants in our Universe.Hawking radiation isn’t just for black holes, study shows

Credit: NASA/Dana Berry, Skyworks Digital Inc.

Self-Gravitational Energy

 Objects that aren’t black holes, what is it, specifically, that will occur? Will this emitted radiation steal energy from the self-gravitational energy of an object like a star or stellar remnant, leading to gravitational contraction? Will it eventually lead to particle decays, or even some sort of phase transition within this object? Or does it imply something far more profound: such as once certain limits are reached and surpassed, that all matter will eventually collapse to a black hole and, via Hawking radiation, eventually decay?

At this point, these are just speculations, as they’re questions that can only be answered by follow-up work. Nevertheless, this paper is a clever line of thought, and does something remarkable: it poses and analyzes a nearly 50-year-old problem in an entirely new way. Perhaps, if nature is kind, this will wind up bringing us closer to resolving some of the key, core issues at the very hearts of black holes. Although it’s still just a suggestion, the implication is certainly worth considering: that all masses, not just black holes, may wind up emitting Hawking radiation.

Phonons may be chiral: Study claims to settle debate

Phonons may be chiral: Study claims to settle debate

This article was reviewed based on Science X’s editorial process and policies. The editors have highlighted the following attributes ensuring the credibility of the content:

verified

peer-reviewed publication

trusted source

correct






To demonstrate the existence of chiral phonons, the researchers used X-ray resonant inelastic scattering (RIXS). Circularly polarized light shines on the quartz. The angular momentum of the photons is transferred to a crystal, in this case causing anions (orange spheres with p-orbitals) to revolution with respect to neighboring cations (green spheres). Credits: Paul Scherrer Institute / Hiroki Ueda and Mahir Dzambegovic

Results published in Nature settle the dispute: phonons can be chiral. This fundamental concept, discovered using circular X-ray light, sees phonons twisting like a corkscrew through quartz.

Throughout nature, at all scales, you can find examples of chirality or handedness. Imagine trying to eat a sandwich with two hands that weren’t enantiomers, non-superimposable mirror images of each other. Consider the drug disasters caused by administering the wrong drug enantiomer or, on a subatomic scale, the importance of the concept of parity in particle physics. Now, thanks to a new study led by researchers at the Paul Scherrer Institute PSI, we know that phonons can also possess this property.

A phonon is a quasiparticle that describes the collective vibrational excitations of atoms in a crystal lattice; imagine it as the Irish Riverdance of the atoms. Physicists have predicted that if phonons can demonstrate chirality they could have important implications for the fundamental physical properties of materials. With the rapid increase in recent years of research into topological materials exhibiting curious electronic and magnetic surface properties, interest in chiral phonons has grown. However, experimental proof of their existence has remained elusive.

What makes phonons chiral is their dance steps. In the new study, atomic vibrations dance in a twist that moves forward like a corkscrew. This corkscrew movement is one of the reasons there has been such a push to discover the phenomenon. If phonons can spin like this, like the coil of wire that forms a solenoid, perhaps they could create a magnetic field in a material.

A new perspective on the problem

It is this possibility that motivated Urs Staub’s group at PSI, which led the study. “It’s because we’re at the junction of ultrafast X-ray science and materials research that we might be approaching the problem from a different perspective,” he says. Researchers are interested in manipulating the chiral modes of materials using circularly polarized chiral light.

He was using such light that the researchers could make their own test. Using quartz, one of the best-known minerals whose atoms silicon and oxygen form a chiral structure, they showed how circularly polarized light couples to chiral phonons. To do this, they used a technique known as resonant inelastic X-ray scattering (RIXS) at the Diamond Light Source in the UK. This was complemented with supporting theoretical descriptions of how the process would create and enable the detection of chiral phonons by groups from ETH Zurich (Carl Romao and Nicola Spaldin) and MPI Dresden (Jeroen van den Brink).

“It doesn’t usually work like that in science”

In their experiment, circularly polarized light shines on the quartz. Photons of light possess angular momentum, which they transfer to the atomic lattice, launching the vibrations in their corkscrew motion. The direction in which the phonons spin depends on the intrinsic chirality of the quartz crystal. As phonons spin, they release energy in the form of scattered light, which can be detected.

Imagine standing on a roundabout and throwing a Frisbee. If you throw the Frisbee in the same direction of movement as the roundabout, you would expect it to zip. Throw it the other way and it will spin less, as the angular momentum of the roundabout and the Frisbee cancel each other out. Similarly, when circularly polarized light twists in the same way as the phonon it excites, the signal is enhanced and chiral phonons can be detected.

A well-planned experiment, accurate theoretical calculations and then something strange happened: almost everything went according to plan. As soon as they analyzed the results, the difference in the response to the light chirality flip was undeniable.

“The results were convincing almost immediately, especially when we compared the difference with the other enantiomers of quartz,” recalls Hiroki Ueda, PSI scientist and first author of the publication. Sitting at his computer analyzing the data, Ueda was the first to see the results: “I kept checking my analysis codes to make sure it was true.” Staub points out, “That’s not normal! It doesn’t usually work like that in science!”

While searching for chiral phonons, there were several false alarms. Will this settle the debate? “Yes, I think so, that’s the beauty of this work,” believes Staub, whose opinion was shared by reviewers of Nature. “Because it’s simple and beautiful and straightforward. It’s obvious. It’s so simple, it’s obvious that this is chiral motion.”

More information:
Hiroki Ueda et al, Chiral phonons in quartz probed by X-rays, Nature (2023). DOI: 10.1038/s41586-023-06016-5

About the magazine:
Nature

#Phonons #chiral #Study #claims #settle #debate

A new study asks whether racehorses have reached their genetic peak

A new study asks whether racehorses have reached their genetic peak

for decades there was an apparent paradox in horse racing. The sport is lucrative (Mage, this year’s Kentucky Derby winner, earned his owner $1.9 million) and the fastest horse wins. Horses with good results and a good pedigree are used as breeding stock for the next generation. Horse breeders were armed with a lot of data, a single trait to optimize, and strong incentives to do so. Yet several studies have suggested that despite their best efforts, race times were not improving.

The most common explanation was that, physiologically speaking, it was always more difficult to breed a horse that could run faster than existing horses already do. The modern Thoroughbred racehorse dates back at least three centuries. Perhaps the years of selective breeding had already discovered and exploited almost all the genetic potential of the breeds.

This made no sense to Patrick Sharman, a racing enthusiast and geneticist at the University of Exeter, England. After all, cattle breeding has been going on for hundreds of years, yet it continues to create cows that produce more milk. Artificial selection applied to chickens is still breeding plumper birds. It would be strange, he thought, if racehorses were the one domesticated animal that humans could no longer improve. Then, along with Alastair Wilson, who had once been his Phd supervisor, started digging.

Their first paper was published in 2015 and looked at a much larger dataset of British breeds dating back to the 1800s than other papers. He found that, contrary to accepted wisdom, horses actually got faster. In sprint races, those covered five to seven furlongs (1-1.4 km), the average speed needed to win has increased by about 0.1 percent every year since 1997. Their latest paper, published May 27 in Inheritance, try to gauge how much of that improvement is attributable to genetics. In other words, is the time-, energy- and money-intensive profession of horse breeding worth it?

The answer seems to be yes, although less so than farmers might like. Linking a large performance database, containing nearly 700,000 race times recorded in Britain between 1995 and 2014, to a family tree of over 76,000 horsepower, they found that speed is heritable, albeit weakly, and that breeding he is improving it, but slowly.

The drive is more pronounced for sprints and middle-distance races (812 furlongs). Drs Sharman and Wilson conclude that about 12% of the variation in horse speed at these distances comes down to genetics. (This is roughly the same heritability as neuroticism, extraversion, or lifespan in humans.) And they found that improvements to that genetics accounted for more than half of the speed increase observed over that time period. . The rest, Dr. Sharman says, is likely due to non-genetic factors like better nutrition or veterinary care for better maneuvering technique.

When it comes to long-distance racing, it’s not clear if the times are improving. One reason, says Dr. Sharman, it could be that genes that are good for sprinting don’t necessarily make good endurance athletes. It appears that breeders select for sprint performance because it offers faster commercial returns. Sprinters tend to start racing around the age of two, long-distance horses at three.

Horse breeders can also face other trade-offs. Selecting solely for speed can increase your risk of injury. (Churchill Downs Racecourse, where the Kentucky Derby is run, suspended racing for a month from June 7, after more than a dozen horses had died of injuries in the past six weeks). Temperament also matters: a fast horse is of little use if it is not rideable.

Despite the difficulties, there is also evidence that breeders may be leaving some potency in the gene pool. At least in Britain, says Dr. Sharman, breeders still rely, to some extent, on their professional judgment when evaluating horses. Less intuitive, more objective statistical techniques have transformed other sports, most famously baseball, over the past two decades. Even horse racing may be ripe for its Moneyball moment.

#study #asks #racehorses #reached #genetic #peak

Ozempic: Study finds it could work in pill form

A woman is seen looking at her phone.

A woman is seen looking at her phone.Share on Pinterest
The drug Ozempic may become available in pill form. FreshSplash/Getty images
  • Novo Nordisk is testing whether an Ozempic pill is as effective as the popular injectable form of the drug.
  • Early research has shown promising results.
  • Semaglutide is a drug developed to treat type 2 diabetes by regulating insulin by mimicking a hormone in the body called GLP-1.

The weight loss journey for many people is a struggle, but with the recent surge and use of drugs like Ozempic and Wegovy, people are finding it easier to lose the extra weight.

Semaglutide, the drug in Ozempic and Wegovy, is currently administered into the body through injections. However, pharmaceutical companies are experimenting with an oral pill form of this weight loss drug with promising results.

In a recent press release, Novo Nordisk, the company that makes Ozempic and Wegovy, announced promising results in a Phase 3a study evaluating the efficacy and safety of this weight-management drug.

The study involved 667 adults with obesity or overweight with at least one comorbidity. It found that the 50 mg oral form of semaglutide resulted in a 15.1% weight loss compared to 2.4% in the placebo group.

Martin Holst Lange, executive vice president of development at Novo Nordisk, said he was pleased with the results, and the choice between a daily tablet or a weekly injection for obesity has the potential to give patients and healthcare professionals the opportunity to choose what best suits the individual’s treatment preferences, in a corporate statement.

Dr. Louis J. Aronne, director of the Comprehensive Weight Management Center at Weill Cornell Medicine, finds the oral option compelling and creates a greater outreach.

Many people prefer oral dosing. Once-a-week injections, however, are very simple to administer and in some ways more cost-effective. Oral dosing increases the range of people who can be treated with these drugs, he tells Healthline.

According to Harvard University, approximately 69% of US adults are considered overweight or obese. THE Center for Disease Control and Prevention reports that as of 2020, the prevalence of severe obesity has increased from 4.7% to 9.2%.

Obesity and being overweight increase your risk of heart disease, stroke and diabetes and can increase your risk of developing some types of cancer.

Semaglutide is a drug developed to treat type 2 diabetes by regulating insulin by mimicking a hormone in the body called GLP-1.

GLP-1 can also tell the brain that the stomach is full, even if it isn’t, resulting in decreased appetite, less desire to eat, and eventual weight loss.

Ozempic is currently approved for the treatment of type 2 diabetes, but Wegovy, which uses the same drug semaglutide, has been approved for weight loss.

In their current form, these drugs are currently being administered by injection into the waist, thigh, or even the upper arm once a week. Sometimes this can not only be uncomfortable for patients, but also create more hesitation in taking medications.

An oral form of semaglutide is already available under a different brand name, Rysbelsus. However, at the prescribed dose, it has not shown efficacy in regards to weight loss. This drug is prescribed at 14mg at most and at that dose it does not help in weight loss.

Novo Nordisk’s recent oral drug study showed weight loss results at 50mg.

It may be likely that higher doses taken by mouth than injected subcutaneously could result in more gastrointestinal distress for some patients, but that remains to be seen once the drug makes its way to market, said Dr. Sahar Takkouche, chief expert in Bariatric and Obesity Medicine and Assistant Professor in the Division of Diabetes, Endocrinology and Metabolism at Vanderbilt University Medical Center in Tennessee.

Some patients may be more tolerant than others when it comes to side effects as there is variation with any drug.

Despite the newfound popularity of these drugs, they come with side effects, both in injectable and oral forms. The study showed that the most common side effect associated with these drugs is gastrointestinal upset. However, gastrointestinal problems are also associated with injection forms including nausea, constipation, diarrhea, vomiting, belching, and generalized abdominal pain.

With semaglutide causing gastrointestinal distress, Aronne recommends taking them on an empty stomach at least half an hour away from food and other medications, and you can’t take them with all other medications.

Besides the side effects, these drugs can also be expensive. Some insurance companies cover these drugs for diabetes treatment, but many don’t cover them for weight loss that costs people about $1,000 out of pocket a month for treatment.

Many insurance companies do not recognize obesity as a medical condition and view the treatment of this disease as purely cosmetic, says Takkouche.

He continues, this paradigm is invalid and puts our patients and the US population at risk of further decline while increasing the cost of health care for all.

Other companies are quickly racing to create oral drugs for diabetes and weight loss as well.

Pfizer is currently developing danuglipron, another oral drug for diabetes and weight loss. The company recently published a study in the journal JAMA network open as for a tablet twice a day which is said to be taken with food, which is different from oral forms of semaglutide.

Similarly, for semaglutide, this drug mimics GLP-1 to not only help regulate insulin, but also tell the brain that the stomach is full and help regulate weight loss.

While these drugs are compelling, not all of them are the perfect fit for them.

The best candidates for this drug are patients with a BMI greater than 30 or a BMI greater than 27 plus an obesity-related comorbidity such as type 2 diabetes, hypertension, hyperlipidemia, obstructive sleep apnea or fatty liver, Takkouche explained.

Drug therapy is a compelling way for many to lose weight if diet and exercise are not suitable options for an individual and with different companies working to approve oral medications, the number of people eligible for these drugs could increase.

Dr. Rajiv Bahl, MBA, MS, is an emergency medicine physician, board member of the Florida College of Emergency Physicians, and health writer. You can find it at RajivBahlMD.

#Ozempic #Study #finds #work #pill #form

Study of geomagnetic field shielding patterns over the past 100,000 years

Study of geomagnetic field shielding patterns over the past 100,000 years

This article was reviewed based on Science X’s editorial process and policies. The editors have highlighted the following attributes ensuring the credibility of the content:

verified

trusted source

correct






Dipole power (a) and non-dipole power (b) evaluated at the Earth’s surface over the last 100 ka, as predicted by five continuous spherical harmonic geomagnetic field models: IMOLEe (Leonhardt et al., 2009), CALS10k.2 (Constable et al ., 2016), GGF100k (Panovska et al., 2018b), LSMOD.2 (Korte et al., 2019b) and GGFSS70 (Panovska et al., 2021). Five global and regional excursions are labeled on the top panel at: PB: Post Blake, NGS: NorwegianGreenland Sea, La: Laschamps, ML: Mono Lake/Auckland, and HP: Hilina Pali. The gray areas indicate the three excursions studied in more detail here: NGS, La and ML. The model time intervals and the models used to calculate Rc100k are indicated by the colored bars below. Credit: Journal of Space Weather and Space Climate (2022). DOI: 10.1051/swsc/2022027

New models of how the geomagnetic field that protects Earth’s atmosphere from cosmic rays has changed over tens of thousands of years can help us understand how climate has changed over a similar timescale.

Earth’s atmosphere is protected from the impact of cosmic rays and other energetic particles by a magnetic field, the geomagnetic field, which extends into space from our planet’s molten outer core. The strength of the geomagnetic field is not constant but varies over time scales of thousands and tens of thousands of years.

Now, a team of Chinese and German scientists, led by Jiawei Gao of the Institute of Geology and Geophysical Sciences of the Chinese Academy of Sciences in Beijing, has modeled fluctuations in the field over the past 100,000 years. Their research is published in Journal of Space Weather and Space Climate.

The geomagnetic field is a natural but very beneficial phenomenon as it protects the earth’s atmosphere from the impact of cosmic rays and other energetic particles, which produce long-lived radionuclides such as carbon-14. As it weakens, the flux of cosmic rays reaching the Earth increases. We know, for example, that every few tens of thousands of years the field experiences an “excursion” or “reversal” that significantly decreases its strength, and weaker and more rapid fluctuations superimpose such long-term changes.

“The global flux of cosmic rays reaching Earth’s atmosphere was up to three times higher at the midpoint of the so-called Laschamps excursion about 34,000 years ago than it is today, and about twice as high in another excursion about 65,000 years ago. years ago,” says Gao.

Understanding these changes over time can help us understand long-term patterns of solar activity and non-anthropogenic climate changes, ie those not caused by human activity, that occurred during prehistory. It is possible to measure the strength of the geomagnetic field shielding using a parameter of momentum per unit charge known as “stiffness”.

Charged particles with equal stiffness move in the same way. If one examines all charged particles moving towards the atmosphere at a given position and angle of incidence, only those with stiffness above a certain value will be able to penetrate it. This value, or the “geomagnetic shear stiffness” is a direct measure of the strength of the geomagnetic field and, therefore, of the degree of shielding.

Gao and his collaborators estimated the global shear stiffness using models of the geomagnetic field at individual time points during the last 100,000 years, comparing and combining four different models of the field.

“Early models were based on dipolar field assumptions. All advanced geomagnetic field models also include non-dipolar components, which are more accurate than those involving only dipolar components,” he says. ‘Using these models, we found that, during excursions (i.e. when the field strength is low) the flux of energetic cosmic rays in the atmosphere was high and, moreover, it was almost independent of latitude.’

These ‘best available models’ developed by the research team allow scientists to estimate the rate of radionuclide production and thus the cosmic radiation dose rate and solar activity during this period. This will help them explore how the climate changed throughout prehistory, which should provide useful insights into the mechanisms and effects of anthropogenic climate change today. Although high-energy particles from outside the solar system can affect Earth’s climate, there is scientific consensus that these factors are not responsible for the warming trend we have seen in recent decades. Recent global warming and associated climate change are attributed to human activities, especially greenhouse gas emissions.

More information:
Jiawei Gao et al, Shielding of the geomagnetic field over the past hundred thousand years, Journal of Space Weather and Space Climate (2022). DOI: 10.1051/swsc/2022027

#Study #geomagnetic #field #shielding #patterns #years

Study: Earth’s first flowering plants were pollinated by insects | Ski.News

Macroevolution of pollination modes across flowering plants, showing the proportional marginal probability of pollination mode at ancestral nodes for each flowering plant order.  Image credit: Stephens et al., doi: 10.1111/nph.18993.

Most living angiosperms (flowering plants) are pollinated by insects, and the new reconstruction of angiosperms’ ancestral pollination pattern suggests that their most recent common ancestor was also insect pollinated.

Macroevolution of pollination modes across flowering plants, showing the proportional marginal probability of pollination mode at ancestral nodes for each flowering plant order.  Image credit: Stephens et al., doi: 10.1111/nph.18993.

Macroevolution of pollination modes across flowering plants, showing the proportional marginal probability of pollination mode at ancestral nodes for each flowering plant order. Image credit: Stephens et al., doi: 10.1111/nph.18993.

Pollination is a key ecological process that has influenced the diversification of many seed plant families throughout evolutionary history, said the Macquarie University Ph.D. student Ruby Stephens and colleagues.

Both gymnosperms and angiosperms depend on pollination to reproduce sexually, with pollen transfer done by insects, vertebrates, wind or water as vectors.

Shifts between different pollinators or modes of pollination are often implicated in the speciation of closely related plants, and pollination shifts of angiosperms have driven the evolution of the wide range of floral forms present today.

Precisely how the first angiosperms were pollinated and how pollination patterns evolved over time remains a key question in angiosperm macroevolution, they added.

Most angiosperms are pollinated by animals, especially insects (e.g. bees, flies, wasps, moths, butterflies, beetles and thrips) but also vertebrates (e.g. birds, bats, lizards and small mammals).

In fact, although some flowers are self-pollinating, up to a third of flowering plants produce no seed without animal pollination.

However, abiotic pollination by wind or water also occurs in many different plant lineages, and wind pollination is estimated to have evolved at least 65 times across flowering plants.

3D model of the ancestral flower reconstructed by the eFLOWER team.  Image credit: Sauquet et al, doi: 10.1038/ncomms16047.

3D model of the ancestral flower reconstructed by the eFLOWER team. Image credit: Sauquet et aldoi:10.1038/ncomms16047.

In their research, the scientists used a state-of-the-art evolutionary tree of all flowering plants, unveiling data on what pollinates 1,160 species in all major flowering plant families.

The evolutionary tree shows us which plant families evolved when, Stephens said.

By running several models, we can map backwards from what pollinates a plant in the present, to what that plant’s ancestor may have pollinated in the past.

This is a significant discovery, revealing a key aspect of the origin of nearly all plants on Earth today.

Plants are the lifeblood of our planet, and our study underscores the importance of insects for plant reproduction throughout Earth’s history.

Our research has uncovered insights into the evolution of other forms of pollination, said Herv Sauquet, a researcher at the Botanic Gardens of Sydney.

Pollination by vertebrate animals such as birds, bats, small mammals, even lizards, has evolved and regressed numerous times throughout history.

Wind pollination has also evolved many times over, but it’s more difficult to reverse: once plants are wind pollinated, they rarely come back.

The research also reveals that wind pollination is more likely to evolve in open habitats towards the poles, while animal pollination is more likely to occur in closed rainforests near the equator.

About 90 percent of the estimated 330,000 angiosperm species today depend on animals for pollination, said Washington University professor Susanne Renner, who was not involved in the study.

The new findings confirm that insects have been pollinating flowering plants for most of the plant lineage’s history.

This underlines the need for insect conservation: their role as pollinators is essential for the continued existence of plants.

The results appear in the journal New phytologist.

_____

Ruby E. Stephens et al. Insect pollination for most of the evolutionary history of flowering plants. New phytologist, published online June 5, 2023; doi: 10.1111/nph.18993

#Study #Earths #flowering #plants #pollinated #insects #Ski.News

Loud Launches: Researchers study how rocket noise affects endangered wildlife

A flock of birds takes flight during the rollout of the space shuttle atlantis to the launch pad in 1988.

Rocket launches are extreme events, for both animals and humans.

“When the [space] shuttle lifts off, main engines roar so loud that a person standing near the pad would be killed, not by the heat from the exhaust, but by the noise of the engines,” Rodney Rocha, former chief structural engineer at NASA Johnson Space Center in Houston, She said in a 2005 interview with the space agency.

#Loud #Launches #Researchers #study #rocket #noise #affects #endangered #wildlife

Arctic could be free of sea ice in summer by 2030, warns new study | Cnn

Arctic could be free of sea ice in summer by 2030, warns new study |  Cnn

Lisi Niesner/Reuters

Ice on Svalbard, Norway, April 6, 2023. This part of the Arctic is warming up to seven times faster than the global average.



Cnn

The Arctic could be free of sea ice about a decade sooner than expected, scientists warn another clear sign that the climate crisis is happening faster than expected as the world continues to pump out planet-warming pollution.

A new study published Tuesday in the journal Nature Communications found that Arctic sea ice could disappear completely during September as early as 2030. Even if the world makes significant cuts in global warming pollution today, the Arctic could still see sea ​​ice-free summers by 2050, scientists report.

The researchers analyzed the changes from 1979 to 2019, comparing different satellite data and climate models to assess how Arctic sea ice was changing.

They found that sea ice decline was largely the result of human-caused pollution and global warming, and previous models had underestimated melting trends in Arctic sea ice.

We were surprised to find that there will be an ice-free Arctic in the summer, regardless of our efforts to reduce emissions, which we did not expect, Seung-Ki Min, lead author of the study and a professor at Pohang University of Science and Technology in South Korea, he told CNN.

Arctic ice builds up during the winter and then melts in the summer, typically reaching its lowest levels in September, before the cycle starts again.

Once Arctic summers become ice-free, sea ice accumulation in colder seasons will be much slower, Min said. The hotter it gets, the more likely it is that the Arctic will remain sea ice-free during the colder season. cold.

Under a path of higher emissions where the world continues to burn fossil fuels and levels of pollution that warm the planet continue to rise the study predicts that the Arctic will see a complete loss of sea ice from August through October before 2080, Min said.

Lisi Niesner/Reuters

Arctic sea ice near the coast of Svalbard, Norway, April 5, 2023.

The study’s findings contrast with the 2021 State of the Science report from the United Nations’ Intergovernmental Panel on Climate Change, which found that the Arctic would be virtually ice-free by mid-century under intermediate greenhouse gas emission scenarios. and elevated.

This new study shows it could happen 10 years sooner, regardless of emission scenarios, Min said.

In recent decades, the Arctic has warmed four times faster than the rest of the world, a 2022 study showed. There has already been rapid sea ice loss in the region, with September sea ice shrinking at a rate of 12.6% per decade, according to NASA.

An Arctic without summer sea ice would send terrible ripple effects around the world. The bright white ice reflects solar energy away from the Earth. As this ice melts, it exposes the darker ocean, which absorbs more heat causing further warming, a feedback process called Arctic amplification.

Sea ice decline can also have an effect on global climate that extends far beyond the Arctic.

We need to prepare very soon for a world with a warmer Arctic, Min said. Since the warming Arctic is suggested to bring extreme weather events such as heatwaves, wildfires and floods to northern mid- and high-latitudes, the earlier start of an ice-free Arctic also implies that we will experience extreme events faster than expected.

A sea ice-free Arctic could also lead to increased commercial shipping as new routes open, which would have a knock-on effect. According to last year’s annual Arctic Scoreboard from the National Oceanic and Atmospheric Administration, increased shipping traffic would lead to more emissions and pollution in the region.

Mika Rantanen, a researcher at the Finnish Meteorological Institute and lead author of the 2022 study, told CNN that the study released on Tuesday benefited from an innovative and cutting-edge methodology to predict when the Arctic will be ice-free.

The methodology is very careful and carries a high degree of certainty in the attribution, said Rantanen, who was not involved in the study. The most surprising finding is not that the loss of sea ice is attributed to rising greenhouse gases, which was already widely known, but that they project an ice-free Arctic sooner than previously thought by about a decade.

Min said the findings show the Arctic is on the verge of becoming very ill and the region has reached a tipping point.

We can look at Arctic sea ice as our body’s immune system that protects our body from harmful things, Min said. Without the protector, conditions in the Arctic will quickly go from bad to worse.

#Arctic #free #sea #ice #summer #warns #study #Cnn

Natural eyebrow shape is genetic – study

Natural eyebrow shape is genetic - study

Numerous people, especially actresses and other female celebrities, have been recognized as having “iconic eyebrows”. These include Marlene Dietrich, Frido Kahlo, Lauren Bacall, Marilyn Monroe, Elizabeth Taylor, Audrey Hepburn, Brooke Shields and Madonna.

Cosmetics, including eye pencils, eye shadows or powders, can help you create your look, but according to a new study conducted by the International Visible Trait Genetics Consortium (VisiGen) and published as a letter to the editor of the Journal of Investigative Dermatology Under the heading “Genome-wide association studies identify DNA variants affecting eyebrow thickness variation in European and continental populations,” the shape of your natural eyebrows is in your genes.

The first gene mapping study on eyebrow thickness in Europeans uncovered three previously unreported genetic loci and showed that eyebrow appearance has partly the same and partly different underlying genes in people from different parts of the world.

The look of human eyebrows isn’t just a matter of grooming, it’s in the genes. Eyebrow thickness, like any other aesthetic trait, is highly heritable. Until now, genetic knowledge of eyebrow thickness was very limited and limited exclusively to non-Europeans. This study is the first genome-wide association study of eyebrow thickness in Europeans. By identifying new genes and rediscovering some of the previously identified genes in non-Europeans, the study expands genetic knowledge on human eyebrow variation, which is of wide interest and has implications for dermatology and other fields.

Sample images illustrating eyebrow thickness classified into three categories, namely 0-thin, 1-intermediate and 2-thick (credit: Journal of Investigative Dermatology)

Eyebrow thickness among Europeans has never been reported

Previous studies have been conducted among Latino and Chinese individuals, establishing four genetic loci associated with eyebrow thickness. Since no European eyebrow thickness had been reported, the researchers did not know whether the genetic effects of eyebrow thickness described in non-Europeans persisted in Europeans or whether there were specific European genetic loci involved in eyebrow thickness, or both.

Lead researcher Prof. Manfred Kayser from the Department of Genetic Identification at Erasmus MC University Medical Center in Rotterdam, The Netherlands, who is chair of the consortium, commented: ‘Despite immense efforts in mapping the genes underlying complex human traits, we know “even more about the genes that make us sick than the ones behind our healthy appearance. We have discovered new genes involved in eyebrow variation in Europeans and rediscovered some of the previously identified genes in non-Europeans.”

The study of nearly 10,000 individuals from four European ancestry groups not only uncovered three previously unreported genetic loci associated with eyebrow thickness, but also rediscovered two of the four genetic loci previously found in non-Europeans.

Kayser concluded that “our study significantly improves the genetic understanding of human eyebrow appearance by increasing the number of known genes from four to seven and provides new targets for future functional studies. Having demonstrated that eyebrow variation is driven by genetic factors shared and distinct among continental populations, our findings underscore the need to study populations of diverse origins to unravel the genetic basis of human traits, including, but not limited to, physical appearance.

#Natural #eyebrow #shape #genetic #study

Sylvester Study: Treatment patterns, not genetics, drive disparities in prostate cancer | Coral Gables Community News #

Sylvester study: Treatment patterns, not genetics, drive prostate cancer disparities

Sylvester study: Treatment patterns, not genetics, drive prostate cancer disparities
Dr. Brandon Mahal, assistant professor of radiation oncology at Sylvester and senior author of the studies.
(Photo courtesy of Sylvester Comprehensive Cancer Center)

Why do men of African descent die of prostate cancer more frequently than other men and suffer the greatest burden of advanced prostate disease globally?

A large-scale retrospective analysis by researchers at the Sylvester Comprehensive Cancer Center at the University of Miami Miller School of Medicine suggests that differences in treatment, rather than genetics, likely explain the disparities in advanced prostate cancer among men of African and European ancestry.

The study of nearly 13,000 men with advanced prostate cancer, published May 24 in The Lancet Digital Health, is one of the most comprehensive studies to date of prostate cancer disparities among men of these ethnicities.

I believe this is the largest and most representative genomic study of advanced prostate cancer in men of African and European ancestry, said Dr. Brandon Mahal, assistant professor of radiation oncology at Sylvester and senior author of the study.

The data clearly show no notable differences in gene mutations between ancestors we would like to target for treatment, suggesting that these mutations are likely not driving disparities in advanced prostate cancer, said Dr. Mahal.

Mahal and coauthors found that men of African descent, despite being at higher risk of developing aggressive prostate disease, were less likely to obtain a complete genetic profile of their tumors at the start of treatment. That means they don’t benefit as often as their European counterparts from sophisticated tests that can guide gene-targeted therapy and lead to better patient outcomes. Instead, they may undergo other, sometimes less effective, treatments as their cancer progresses.

Men of African descent were also less likely than men of European descent to undergo clinical trials for prostate cancer, which typically involve newer, more effective treatments for the aggressive disease, Mahal noted.

We’ve known for a couple of decades that prostate cancer disparities are some of the biggest disparities we see across all types of cancer. This research can help focus our efforts on what is needed to address these disparities, she said, adding that future studies should not ignore the examination of genomics.

While this study looked at advanced prostate cancer and diminished the focus on genomics as a reason for the disparities, there is still a case for studying the role of genomics in men’s risk of developing prostate cancer, Mahal concluded.

Sylvester worked on this study in collaboration with researchers at Foundation Medicine, the University of Michigan and Harvard Medical School.

WHO WE ARE:

For more Miami community news, look no further than Miami Community Newspapers. This group of online Miami newspapers covers a variety of topics about the local community and beyond. Miami’s community newspapers offer daily news, online resources, podcasts, and other multimedia content to keep readers informed. With topics ranging from local news to community events, Miami’s community newspapers are the ideal source for staying up to date with the latest news and happenings in the area. Additionally, the paper has exclusive podcasts from the Miami community, providing listeners with an in-depth look at Miami culture. Whether you’re looking for local Miami news or community podcasts, Miamis Community Newspapers has you covered.


Connect with your customers and grow your business

Click here



#Sylvester #Study #Treatment #patterns #genetics #drive #disparities #prostate #cancer #Coral #Gables #Community #News