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Australia wants to ban social media for under-16s, but it won't work

New Scientist Feed - 5 hours 40 min ago
Attempts to prevent Australian children from accessing social media are likely to fail, and could do more harm than good
Categories: Science

Speaking at Brown University Nov 18th

Just a brief note, in a very busy period, to alert those in the Providence, RI area that I’ll be giving a colloquium talk at the Brown University Physics Department on Monday November 18th at 4pm. Such talks are open to the public, but are geared toward people who’ve had at least one full year of physics somewhere in their education. The title is “Exploring The Foundations of our Quantum Cosmos”. Here’s a summary of what I intend to talk about:

The discovery of the Higgs boson in 2012 marked a major milestone in our understanding of the universe, and a watershed for particle physics as a discipline. What’s known about particles and fields now forms a nearly complete short story, an astonishing, counterintuitive tale of relativity and quantum physics. But it sits within a larger narrative that is riddled with unanswered questions, suggesting numerous avenues of future research into the nature of spacetime and its many fields. I’ll discuss both the science and the challenges of accurately conveying its lessons to other scientists, to students, and to the wider public.

Categories: Science

A New Look a the Most Ancient Light in the Universe

Universe Today Feed - 7 hours 46 min ago

In the earliest moments of the Universe, the first photons were trapped in a sea of ionized gas. They scattered randomly with the hot nuclei and electrons of the cosmic fireball, like tiny boats in a stormy sea. Then, about 370,000 years after the big bang, the Universe cooled enough for the photons to be free. After one last scattering, they could finally ply interstellar space. Some of them traveled across 14 billion years of space and time to reach Earth, where we see them as part of the cosmic microwave background. The remnant first light of creation.

The CMB is a central point of evidence supporting the Big Bang and the standard model of cosmology. By observing the scale of fluctuations within the CMB, we can measure things such as the shape of space, the distribution of matter and energy, and the rate of cosmic expansion. It’s that last one that has been troubling astronomers, thanks to the Hubble tension problem.

Astronomers have several ways to measure the Hubble parameter, the value of which tells us the rate of cosmic expansion. The methods generally fall into two types: those based on observations of the CMB, and those based on astrophysical phenomena such as supernovae. The problem is that these two types of methods don’t agree on the value. They even contradict each other, leading some astronomers to argue there must be something wrong with the standard model.

Polarization fluctuations within the CMB. Credit: SPT-3G Collaboration

Of the two types, the CMB method is the one with the most limited data. The best CMB observations we have come from space telescopes such as Planck, which measured fluctuations in CMB intensity. One solution to the tension problem would be to argue that the CMB observations are somehow biased. But new observations gathered by the South Pole Telescope (SPT) throw that idea out of the water.

Rather than measuring intensity fluctuations in the cosmic microwave background, the SPT observed variations in its polarization. All the CMB light we observe comes from a moment of last scattering, when photons scattered off an ion one last time before making the billion-year journey to reach us. When light is scattered, it is polarized relative to the distribution of ionized gas. So these observations are a truly independent measure of cosmic expansion.

Different modes of CMB polarization. Credit: Sky and Telescope

One challenge in working with polarized CMB data is that as the first light traveled through space, it interacted with matter, space, and time. Not only is the light red-shifted due to cosmic expansion, it is gravitationally lensed by galaxies, which changes the polarization. Some of the light scatters off interstellar gas, which gives a false polarization. Even ripples of gravitational waves can affect the light’s orientation. So the team looked at not just the raw polarization of the CMB, but also what are known as E-mode and B-mode polarization. Each of these is sensitive to different kinds of bias. For example, the E-mode is more sensitive to secondary scattering, while the B-mode is more sensitive to cosmic inflation and gravitational waves.

By combining and contrasting these polarization modes, the team was able to calculate a new value for the Hubble parameter. Since it isn’t based on intensity fluctuations, it is free of any bias in the space-based CMB observations. Based on their data, the team got a value of H<sub>0</sub> at 66.0–67.6 (km/s)/Mpc. This agrees with the intensity-based observations of WMAP and Planck, which found a value of 67–68 (km/s)/Mpc. In comparison, the astrophysical methods find a value of 73–75 (km/s)/Mpc.

This study confirms that earlier CMB observations are not biased. The Hubble tension is very real, and we currently have no clear way to resolve it.

Reference: SPT-3G Collaboration. “Cosmology From CMB Lensing and Delensed EE Power Spectra Using 2019-2020 SPT-3G Polarization Data.” arXiv preprint arXiv:2411.06000 (2024).

The post A New Look a the Most Ancient Light in the Universe appeared first on Universe Today.

Categories: Science

Scientists transform blood into regenerative materials, paving the way for personalized, blood-based, 3D-printed implants

Scientists have created a new 'biocooperative' material based on blood, which has shown to successfully repair bones, paving the way for personalised regenerative blood products that could be used as effective therapies to treat injury and disease.
Categories: Science

Novel magnetic field integration enhances green hydrogen peroxide production

A sprinkling of magnetic nanoparticles is just enough to power up catalysts, so they can make hydrogen peroxide production more efficient.
Categories: Science

New route to 'quantum spin liquid' materials discovered

Scientists have produced a new route to materials with complex 'disordered' magnetic properties at the quantum level. The material, based on a framework of ruthenium, fulfils the requirements of the 'Kitaev quantum spin liquid state' -- an elusive phenomenon that scientists have been trying to understand for decades.
Categories: Science

AI models work together faster when they speak their own language

New Scientist Feed - 10 hours 41 min ago
Letting AI models communicate with each other in their internal mathematical language, rather than translating back and forth to English, could accelerate their task-solving abilities
Categories: Science

Satellites spot methane leaks – but ‘super-emitters’ don’t fix them

New Scientist Feed - 11 hours 40 min ago
Governments and companies almost never take action when satellites alert them about large methane leaks coming from oil and gas infrastructure
Categories: Science

COP29 host Azerbaijan faces climate disaster as Caspian Sea dries up

New Scientist Feed - 12 hours 40 min ago
Water levels in the Caspian Sea are set to fall dramatically as the climate gets hotter, posing a major threat to economic activity and ecosystems in the region
Categories: Science

Space Tourism: The Good, The Bad, The Meh

Universe Today Feed - 13 hours 12 min ago

Space tourism here is here to stay, and will likely remain a permanent fixture of near-Earth activities for the foreseeable future. But is it worth it? 

While for decades private individuals have been able to negotiate with national space agencies to get rides to the International Space Station, it wasn’t until the advent of private aerospace that many more opportunities opened up. With wealthy billionaires like Elon Musk, Jeff Bezos, and Richard Branson all creating their own rocket companies, it changed the playing field. Now if you are a private individual wanting to take a hop into space you can shop around with a lot more options.

While Elon Musk’s SpaceX does not have a stated goal of space tourism, if you are willing to front the money you can get a ride on a Crew Dragon capsule, like Jared Isaacman recently did with his Polaris Dawn mission. On the other end of the spectrum, Richard Branson’s Virgin Galactic is explicitly designed around space tourism. They offer short sub-orbital hops for a few hundred thousand dollars each.

Space tourism certainly has several positives. For one there is more interest and activity in space which generally brings positive attention to the industry. Second, by companies chasing after a new market niche, these companies are developing new technologies and approaches which can have further beneficial effects on the larger industry. Lastly, there’s the well-reported “overview effect” where people finally get a view of our fragile home planet and gain a new perspective on what is important in human life.

On the other hand, it’s not exactly like many people get to be space tourists. Even the cheapest tickets are comparable to the cost of a home, making it inaccessible to all but the wealthiest people in our society. So it’s not like many people are getting to appreciate the view or participate in this new market. In fact, space tourism can lead to negative feelings as people just think of space as the province of the rich and elite.

Lastly, there are precious few dollars available for rocket development and space exploration. Many might argue that these dollars would be better suited to scientific exploration or experimental development of new technologies rather than creating a new pastime for the ultra wealthy.

Ultimately space tourism is going to be a thing whether we like it or not. It’s also not going to be a big thing. For the foreseeable future it will remain incredibly expensive, and most rocket companies are more interested in scientific and industrial pursuits in low-Earth orbit and beyond. So either way, whether it’s a good or bad thing, it’s simply not going to make a huge difference.

The post Space Tourism: The Good, The Bad, The Meh appeared first on Universe Today.

Categories: Science

A 200-year-old mystery about newts has finally been solved

New Scientist Feed - 14 hours 41 min ago
A genetic flaw dooms half of all crested newts to die before they hatch – now we know how this baffling evolutionary quirk came about
Categories: Science

A unique pair of galactic lenses may help solve a cosmological riddle

New Scientist Feed - 15 hours 33 min ago
Two massive galaxies are bending light from the same distant quasar, creating a so-called Einstein zigzag lens that could help astronomers pin down how quickly the universe is expanding
Categories: Science

How we misunderstood what the Lucy fossil reveals about ancient humans

New Scientist Feed - 15 hours 40 min ago
It has been 50 years since archaeologists discovered Lucy, perhaps the most famous ancient hominin ever found. But the scientists who have studied her say that this fossil gave us a misleading image of the nature of her species
Categories: Science

There's a new twist on the famous invisible gorilla psychology study

New Scientist Feed - 17 hours 41 min ago
A classic study found that people can fail to notice a gorilla when they are focusing on something else, but new experiments suggest this "inattentional blindness" might not tell the whole story
Categories: Science

If You Sanewashed RFK Jr., Or If You Sanewashed Doctors Who Did, You Own the Next 4 Years

Science-based Medicine Feed - 18 hours 36 min ago

When RFK Jr. does to the U.S. what he did to Samoa, doctors will say they are horrified, that they love vaccines, blah blah blah. But it will be too late.

The post If You Sanewashed RFK Jr., Or If You Sanewashed Doctors Who Did, You Own the Next 4 Years first appeared on Science-Based Medicine.
Categories: Science

New Study Examines Cosmic Expansion, Leading to a New Drake Equation

Universe Today Feed - Thu, 11/14/2024 - 2:31pm

In 1960, in preparation for the first SETI conference, Cornell astronomer Frank Drake formulated an equation to calculate the number of detectable extraterrestrial civilizations in our Milky Way. Rather than being a scientific principle, the equation was intended as a thought experiment that summarized the challenges SETI researchers faced. This became known as the Drake Equation, which remains foundational to the Search for Extraterrestrial Intelligence (SETI) to this day. Since then, astronomers and astrophysicists have proposed many updates and revisions for the equation.

This is motivated by ongoing research into the origins of life on Earth and the preconditions that led to its emergence. In a recent study, astrophysicists led by Durham University produced a new model for the emergence of life that focuses on the acceleration of the Universe’s expansion (aka. the Hubble Constant) and the number of stars formed. Since stars are essential to the emergence of life as we knot it, this model could be used to estimate the probability of intelligent life in our Universe and beyond (i.e., in a multiverse scenario).

The study was led by Daniele Sorini, a postdoctoral Research Associate at Durham University’s Institute for Computational Cosmology, and was funded by a European Research Council (ERC) grant. She was joined by John Peacock, a Professor of Cosmology at the Royal Observatory and the University of Edinburgh’s Institute for Astronomy, and Lucas Lombriser, from the Département de Physique Théorique, Université de Genève. The paper that details their findings was recently published in the Monthly Notices of the Royal Astronomical Society.

The Drake Equation is a mathematical formula for the probability of finding life or advanced civilizations in the universe. Credit: University of Rochester

As noted, the Drake Equation was not intended as a tool for estimating the number of extraterrestrial intelligences (ETIs) but as a guide for how scientists should search for life in the Universe. The formula for the equation is:

N = R* x fp x ne x fl x fi x fc x L

Whereas N is the number of civilizations in our galaxy that we might able to communicate with, R* is the average rate of star formation in our galaxy, fp is the fraction of those stars that have planets, ne is the number of planets that can actually support life, fl is the number of planets that will develop life, fi is the number of planets that will develop intelligent life, fc is the number civilizations that would develop transmission technologies, and L is the length of time that these civilizations would have to transmit their signals into space.

In the same sense, the new research does not attempt to calculate the absolute number of intelligent species in the Universe. Instead, the team presents an analytical model for cosmic star formation history to measure the impact of cosmological parameters within the most widely accepted cosmological model. This is none other than the Lambda-Cold Dark Matter (LCDM) model, where Dark Matter and Dark Energy (Lambda) account for roughly 95% of the matter-energy density of the Universe. The remaining 5%, the “ordinary” matter we see every day, is what scientists refer to as baryonic matter (aka. “luminous matter”).

In their paper, the team calculated the fraction of ordinary matter that is converted into stars over the entire history of the Universe based on different Dark Energy densities. Stars are essential to life, creating heavier elements through nuclear fusion that allow for planet formation, biochemistry, and all life as we know it. Their model predicts that the most efficient density for star formation would be 27%, compared to 23% scientists have observed in our Universe. In short, their results suggest that our Universe is an outlier in the context of the multiverse.

Early Dark Energy could have caused early seeds of galaxies (depicted at left) to sprout many more bright galaxies (at right) than theory predicts. Credit: Josh Borrow/Thesan Team

These findings could have significant implications for cosmology and the ongoing debate about whether or not our Universe is “fine-tuned” for life. As Dr. Sorini explained in a Royal Astronomical Society press release:

“Understanding Dark Energy and the impact on our Universe is one of the biggest challenges in cosmology and fundamental physics. The parameters that govern our Universe, including the density of dark energy, could explain our own existence. Surprisingly, though, we found that even a significantly higher dark energy density would still be compatible with life, suggesting we may not live in the most likely of Universes.”

The new model could also provide insight into how differing densities of Dark Energy affect the formation of the Universe and the development of conditions that allow life to emerge. The influence of Dark Energy drives cosmic expansion, causing the large-scale structures of the Universe (galaxies and galaxy clusters) to move farther and farther apart. For life to develop, matter must be able to clump together to form stars and planets and remain stable for billions of years – since evolution is a long-term process lasting billions of years.

Another takeaway from this research is that star formation and the evolution of the large-scale structure of the Universe achieve a balance over time. This balance determines the optimal value of Dark Energy density needed for the emergence of life and the eventual development of intelligent life. Said Prof. Lombriser: “It will be exciting to employ the model to explore the emergence of life across different universes and see whether some fundamental questions we ask ourselves about our own Universe must be reinterpreted.”

The Drake Equation may need additional parameters, including a Lambda energy density (ld) and a multiverse (mv) parameter. Regardless, the search for life and the question of how it can arise endure, much like Frank Drake’s equation itself!

Further Reading: Royal Astronomical Society, MNRAS

The post New Study Examines Cosmic Expansion, Leading to a New Drake Equation appeared first on Universe Today.

Categories: Science

Pentagon’s Latest UFO Report Identifies Hotspots for Sightings

Universe Today Feed - Thu, 11/14/2024 - 2:04pm

The Pentagon office in charge of fielding UFO reports says that it has resolved 118 cases over the past year, with most of those anomalous objects turning out to be balloons. But it also says many other cases remain unresolved.

This year’s legally mandated report from the Department of Defense’s All-Domain Anomaly Resolution Office, or AARO, also identifies areas of the world that seem to be hotspots for sightings of unidentified flying objects. Such objects have been re-branded as unidentified anomalous phenomena, or UAPs.

Today’s report come just one day after a House subcommittee hearing about UAPs, during which witnesses — and some lawmakers — voiced concerns about potential alien visitations and undisclosed efforts to gather evidence. In contrast, the Pentagon’s report for the 2023-2024 time period states that, “to date, AARO has discovered no evidence of extraterrestrial beings, activity or technology.”

“AARO has successfully resolved hundreds of cases in its holdings to commonplace objects such as balloons, birds, drones, satellites and aircraft,” the office’s director, Jon Kosloski, said in a news release. “Only a very small percentage of reports to AARO are potentially anomalous, but these are the cases that require significant time, resources and a focused scientific inquiry by AARO and its partners.” 

In the past, U.S. military and intelligence officials have suggested that some UAP sightings may be attributable to intrusions by rival powers such as Russia or China. The Chinese spy balloon that was intercepted and destroyed by Air Force fighter jets last year after crossing over the U.S. serves as a prime example.

AARO’s latest report says that U.S. military aircrews provided two reports over the past year that identified flight safety concerns, and three reports described pilots being trailed or shadowed by anomalous objects. “To date, AARO has no indication or confirmation that these activities are attributable to foreign adversaries,” the report says, but the office is continuing to work with the U.S. intelligence community to investigate the cases.

“None of the reports AARO received during the reporting period indicated that observers suffered any adverse health effects,” the report says.

AARO’s reporting system was established to encourage members of the U.S. military to let the Pentagon know about UAP sightings and take the stigma out of the process. Based on the latest numbers, the strategy seems to be working. Between May 2023 and June 2024, AARO received 757 UAP reports, compared with 291 reports for the period between August 2022 and April 2023.

Here are more statistics from today’s report:

  • Of the 757 reports received over the past year, 485 relate to incidents during the yearlong reporting period, and the remaining 272 reports relate to incidents occurring in the 2021-2022 time frame.
  • In addition to the 118 resolved cases, another 174 cases have been queued up for closure, pending a final review and approval by AARO’s director. All those cases were attributed to prosaic objects.
  • Seventy percent of the closed cases in 2023-2024 were attributed to balloons. Sixteen percent were attributed to drones, 8% to birds, 4% to satellites and 2% to birds.
  • AARO determined that 21 cases merited further analysis, based on reported anomalous characteristics or behaviors. Those cases are being studied by AARO’s experts as well as the office’s partners in the intelligence community and the science and tech community. “AARO will provide immediate notification to Congress should AARO identify that any cases indicate or involve a breakthrough foreign adversarial aerospace capability,” the report says.
  • The remaining 444 cases received over the past year lacked sufficient data for further analysis. They’ve been placed in an archive and will be revisited if additional data comes to light. AARO says it has 1,652 UAP reports in all.
  • In addition to reports from the U.S. military, AARO is receiving reports of sightings by civil and commercial pilots via the Federal Aviation Administration. AARO says 392 of the 757 reports received over the past year came from the FAA.
  • AARO says unidentified lights or orb-shaped objects were mentioned most frequently in the subset of UAP reports that included references to visual characteristics. Other reports mentioned cylinders, disks, triangles, squares or exotic objects such as a “green fireball” or “a jellyfish with flashing lights.”

AARO’s global map of UAP reporting hotspots highlights four broad areas: the southeastern U.S. and Gulf of Mexico; the West Coast and Pacific Northwest; the Middle East; and northeastern Asia in the vicinity of Japan and the Korean peninsula. This doesn’t mean the aliens favor those regions. Instead, AARO says the distribution favors a “continued geographic collection bias based on locations near U.S. military assets and sensors operating globally.”

AARO says it’s getting an increasing number of cases that can be traced to sightings of SpaceX’s Starlink satellites. “For example, a commercial pilot reported white flashing lights in the night sky,” the report says. “The pilot did not report an altitude or speed, and no data or imagery was recorded. AARO assessed that this sighting of flashing lights correlated with a Starlink satellite launch from Cape Canaveral, Florida, the same evening about one hour prior to the sighting.”

One of the reports received via the FAA mentioned a possible flight safety issue. “In this instance, a commercial aircrew reported a near miss with a ‘cylindrical object’ while over the Atlantic Ocean off the coast of New York,” the report says. “AARO continues its research into, and analysis of, this case.”

AARO received 18 reports from the Nuclear Regulatory Commission that related to UAP incidents near U.S. nuclear infrastructure, weapons and launch sites. NRC officials attributed all those sightings to drones. One of the incidents, in August 2023, involved the recovery of a crashed drone in the vicinity of the D.C. Cook Nuclear Power Plant in Michigan — but AARO provided no further information about the drone.

What more can be done? In today’s report, AARO says its ability to resolve cases has been constrained due to “a lack of timely and actionable sensor data.”

“AARO continues to address this challenge by working with military and technical partners to optimize sensor requirements, information-sharing processes, and the content of UAP reporting,” the report says. “AARO is also expanding engagement with foreign partners to share information and collaborate on best practices for resolving UAP cases.”

The post Pentagon’s Latest UFO Report Identifies Hotspots for Sightings appeared first on Universe Today.

Categories: Science

Weight-loss medications may also ease chronic pain

New Scientist Feed - Thu, 11/14/2024 - 1:34pm
Popular semaglutide-based drugs used for weight loss may reduce chronic and acute pain, which could make them a promising alternative to opioids
Categories: Science

A New Way to Detect Daisy Worlds

Universe Today Feed - Thu, 11/14/2024 - 1:15pm

The Daisy World model describes a hypothetical planet that self-regulates, maintaining a delicate balance involving its biogeochemical cycles, climate, and feedback loops that keep it habitable. It’s associated with the Gaia Hypothesis developed by James Lovelock. How can we detect these worlds if they’re out there?

By looking closely at information.

A Daisy World (DW) is inhabited by two types of daisies: white and black. They have different albedos, and the blacks absorb more sunlight and warm the planet, while the whites reflect more sunlight and cool the planet.

As the DW’s star brightens, the planet’s temperature rises. At first, black daisies thrive because they absorb more energy. However, as the planet gets hotter, absorbing more energy becomes undesirable, and the white daisies begin to outcompete the blacks and thrive. As they thrive, they reflect more sunlight and cool the planet.

The result is a delicate homeostasis where the daisies regulate the planet’s temperature and keep it in a habitable range. It can’t get too hot and it can’t get too cold. The DW model shows how life can influence a planet’s climate and create conditions favourable for its own survival.

Earth is not exactly a daisy world, but life on Earth influences the climate. The DW model simply illustrates the concept of basic climate feedback mechanisms.

The ESA’s Sentinel 2 satellite captured this image of an algae bloom in the Baltic Sea in 2015. A ship can be seen moving through it. Algae blooms interact with the climate through feedback loops. Image Credit: Copernicus Sentinel data / ESA.

In new research, scientists from the Department of Physics and Astronomy and the Department of Computer Science at Rochester University wanted to find ways to analyze how planetary systems like biospheres and geospheres are coupled. If there are self-regulating “Daisy Worlds” out there, how can we detect them?

The research is “Exo-Daisy World: Revisiting Gaia Theory through an Informational Architecture Perspective.” The lead author is Damian Sowinski, a research physicist and postdoctoral associate in the Department of Physics and Astronomy at the University of Rochester. The research is awaiting publishing and is not peer-reviewed yet.

The idea is to find a way to detect agnostic biosignatures on exoplanets. Regular biosignatures are specific chemicals like oxygen or methane that can be byproducts of living organisms. Agnostic biosignatures are indications that life is present but don’t rely on identifying which types of organisms might be producing them. Instead, they’re like overarching planetary patterns that living worlds produce.

For the authors, finding agnostic biosignatures begins with information and how it flows.

“In this study, we extend the classic Daisy World model through the lens of Semantic Information Theory (SIT), aiming to characterize the information flow between the biosphere and planetary environment—what we term the information architecture of Daisy World systems,” the authors explain.

Semantic Information Theory has been around since the mid-20th century. It attempts to define meaning in different contexts, how human subjective interpretation affects it, and related concepts in the same vein. It’s taken on a new focus as artificial intelligence and machine learning become more prevalent.

There’s a drive to understand exoplanet atmospheres and environments and to have a way to differentiate between those that may be life-supporting and those that aren’t. This is a complex problem that hinges on agnostic biosignatures.

The JWST captured this atmospheric spectrum of exoplanet K2-18 b showing the presence of methane, which can act as a biosignature. The authors say that information theory can help undercover agnostic biosignatures. Rather than specific chemicals like methane, agnostic biosignatures are patterns that can only be created by a biosphere. Image Credit: NASA, CSA, ESA, R. Crawford (STScI), J. Olmsted (STScI), Science: N. Madhusudhan (Cambridge University)

Agnostic biosignatures are complex patterns and structures that can’t be explained by non-biological processes. There’s also disequilibrium, novel energy transfer, unusual levels of organization at different scales, and cyclical or systematic changes that suggest a biological cause.

A search for agnostic biosignatures can involve complex molecules that need biological synthesis, chemical distributions that require metabolism, unexpected accumulations of specific molecules, and features in an atmosphere or on a planetary surface that require biological maintenance.

Some examples of agnostic biosignatures on Earth are methane and oxygen co-existing in the atmosphere, the ‘Red Edge‘ in Earth’s vegetation spectrum, and daily or seasonal cycles of gas emissions.

The Red Edge is a region of rapid change in vegetation reflectance in the near-infrared (NIR). It could be useful in detecting vegetation on exoplanets. Image Credit: Seager et al. 2024.

“The search for life on exoplanets requires the identification of biosignatures, which rely on life having
significantly altered the spectroscopic properties of a planet. Thus, exoplanetary life searches focus not
on detecting individual organisms but on identifying the collective effects of life on the planetary system—what we refer to as exo-biospheres,” the authors explain.

In short, we can’t study biosignatures without studying biospheres. In doing so it’s critical to understand where and how an exo-biosphere reaches a “mature” state where they exert a strong influence on the atmosphere, hydrosphere, cryosphere, and lithosphere, collectively known as the geosphere. Once they’re mature and exert a strong influence, they’re in line with the Daisy World hypothesis.

The authors aim is to study how information flows between a biosphere and the planetary environment. To do this, they modelled potential conditions on M-dwarf exoplanets and came up with equations that describe the co-evolution of the daisies on these worlds with their planetary environments. They created what they term an ‘information narrative’ for exo-Daisy Worlds (eDWs).

Typically, the homeostatic feedback in DWs rests on physical quantities like radiation fluxes, albedos, and plant life coverage fractions. That’s the physical narrative. However, the researchers used Semantic Information Theory to derive a complementary narrative based on how information flows. In their work, SIT focuses on correlations between an agent—the biosphere—and an environment and how those correlations benefit the agent.

Their model showed that as stellar luminosity rises, the correlations between the biosphere and its environment intensify. The correlations correspond to distinct phases of information exchange between the two. This leads to the idea of rein control, a control exerted by flora through the positive and negative differences of their albedos compared to the bare ground. This is how the biosphere exerts a regulatory influence on a planet’s climate. In their informational narrative, the planetary temperatures are more constrained “at the cooler and warmer boundaries of the bearable temperature range.”

Not all of the information that flows between the biosphere and the environment is relevant. The biosphere doesn’t use all of it because some of it doesn’t help the biosphere maintain control. The authors say that by analyzing all this information according to information theory, they can determine which information, and when and how, it contributes to its own viability.

The Daisy World model is instructive, but it’s a toy model. For example, it doesn’t include stochastic events like volcanic eruptions. But the big question is how does it relate to exobiospheres?

The authors say that their work shows the potential in using approaches like SIT to understand how exoplanets and their biospheres co-evolved like they have on Earth. More realistic models will be necessary that include more of the complex networks of interactions between an exoplanet’s living and non-living systems. The biosphere processes information in ways that non-living systems don’t, so information-centric systems can undercover agnostic biosignatures in ways that physical or chemical models can’t.

“As a result, the next step in our research program will involve applying SIT and other information-theoretic approaches to more complex models of coupled planetary systems,” the authors conclude.

The post A New Way to Detect Daisy Worlds appeared first on Universe Today.

Categories: Science

Cash is King: The surprising truth about spending habits in a cashless world

Computers and Math from Science Daily Feed - Thu, 11/14/2024 - 1:14pm
Physical cash not only influences how much we spend but also fosters a profound sense of psychological ownership that digital payments cannot replicate, according to new research.
Categories: Science

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