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A new review shows that this process of thinking is not exclusive to humans. Artificial intelligence, too, is capable of self-correction and arriving at new conclusions through 'learning by thinking.'

Astronomers have spotted the biggest pair of black hole jets ever seen, spanning 23 million light-years in total length. That's equivalent to lining up 140 Milky Way galaxies back to back.

Researchers used advanced machine learning to increase the accuracy of a national cardiovascular risk calculator while preserving its interpretability and original risk associations.

Astronomers examined galaxy Arp 107 which has revealed a wealth of information about star-formation and how two galaxies collided hundreds of million years ago. Arp 107 is located 465 million light-years from Earth in the constellation Leo Minor.

Researchers want to transform the natural and abundant resource wood into useful materials, and central to that is a molecular machine found in fungi that decomposes the complex raw material into its basic components. Researchers have come up with a test feed for the fungal molecular machine that allows them to observe its close-to-natural action, opening the door to improving it and to putting it to industrial application.

A survey reveals that a significant proportion of UK general practitioners (GPs) are integrating generative AI tools, such as ChatGPT, into their clinical workflows. The results highlight the rapidly growing role of artificial intelligence in healthcare -- a development that has the potential to revolutionize patient care but also raises significant ethical and safety concerns.

Scientists have shown that a type of qubit whose architecture is more amenable to mass production can perform comparably to qubits currently dominating the field. With a series of mathematical analyses, the scientists have provided a roadmap for simpler qubit fabrication that enables robust and reliable manufacturing of these quantum computer building blocks.

Scientists have shown that a type of qubit whose architecture is more amenable to mass production can perform comparably to qubits currently dominating the field. With a series of mathematical analyses, the scientists have provided a roadmap for simpler qubit fabrication that enables robust and reliable manufacturing of these quantum computer building blocks.

A new study has successfully used porous liquids to achieve liquid-liquid separation for the first time, creating exciting potential for advancing both environmental sustainability and public health.

Chemists present two studies that open up new possibilities for biotechnological applications.

Spanning 23 million light years, or 220 Milky Way galaxies, a set of giant, newly discovered black hole jets known as Porphyrion may change our understanding of black holes and the structure of the universe

Experiments in a state-of-the-art wave tank suggest we have underestimated the potential size and power of rogue waves and the risk they pose to offshore infrastructure

Simple words like "force" and "particle" can mislead us as to what reality is actually like. Physicist Matt Strassler unpacks how to see things more clearly

An artificial intelligence model that can identify the calls of eight whale species is helping researchers track the elusive whale behind a perplexing sound in the Pacific

Attention-deficit/hyperactivity disorder (ADHD) is one of the most commonly diagnosed neurodevelopment disorders and seems to be on the rise, in both children and adults. The diagnosis in children requires having various symptoms of attention deficit or hyperactivity which is functionally impairing with onset by age 12. Recognition of the disorder actually goes back farther than you might think – the observation that […]

The post Why Is ADHD On The Rise first appeared on Science-Based Medicine.

The second-closest planet to the sun is more geologically active than we thought and could have more than 17,000 venusquakes a year

Located in the constellation Ursa Major, roughly 300 light-years from Earth, is the Sun-like star HD 118203 (Liesma). In 2006, astronomers detected an exoplanet (HD 118203 b) similar in size and twice as massive as Jupiter that orbits very closely to Liesma (7% of the distance between Earth and the Sun), making it a “Hot Jupiter.” In a recent study, an international team of astronomers announced the detection of a second exoplanet in this system: a Super Jupiter with a wide orbit around its star. In short, they discovered a “Cold Super-Jupiter” in the outskirts of this system.

Gracjan Maciejewski – an Associate Professor with the Institute of Astronomy at Nicolaus Copernicus University (NCU) in Torun, Poland – led the study, which recently appeared in the journal Astronomy & Astrophysics. He was joined by researchers from the Department of Astronomy and Astrophysics and the Center for Exoplanets and Habitable Worlds at Pennsylvania State University (PSU), the Instituto de Astrofísica de Canarias, the Agencia Espacial Española (AEE), the Instituto de Astrofísica de Andalucía (IAA-CSIC), and the Center for Astrophysical Surveys at the National Center for Supercomputing Applications (NCSA).

According to their study, the planet (HD 118203 c) is up to eleven times the mass of Jupiter and orbits its parent star at a distance of 6 AU (six times the distance between Earth and the Sun) with a period of 14 years. Astronomers discovered the parent star in 1891 using the Draper telescope, now located in the NCU Institute of Astronomy in Piwnice, near Torun. Liesma is a G-type yellow dwarf (like our Sun), but 20% more massive and twice as large. Astronomers estimate that the star and its entire planetary system are slightly older than the Sun (an estimated 5 billion years).

Henry Draper’s Astrograph (1891), donated by Harvard College Observatory in 1947. Credit: Andrzej Romanski

While astronomers have known that a fairly massive planet orbits HD 118203 for nearly twenty years, it was only in 2006 that it was confirmed using Radial Velocity (Doppler Spectroscopy) measurements. However, these measurements indicated a linear trend that indicated there may be a companion planet with a wider orbit. The presence of another planet would indicate that the system has a hierarchical orbital architecture, which could help astronomers learn more about the origins of hot Jupiters. As Prof. Andrzej Niedzielski, a co-author of the study, explained in an NCU news story:

“Doppler observations, however, indicated that this was not the end of the story, that there might be another planet out there. Therefore, we immediately included this system in our observational programs. At first, as part of the Torun-Pennsylvania exoplanet research program, conducted in collaboration with Professor Aleksander Wolszczan, we tracked the object with one of the largest optical instruments on Earth, the nine-metre Hobby-Eberly Telescope in Texas.”

The results were so promising that the international team continued observing the star using the Telescopio Nazionale Galileo (TNG) at the Roque de los Muchachos Observatory. But first, it was necessary to rule out the possibility that more planets were hiding in the system. “I analyzed photometric observations obtained with the Transiting Exoplanet Survey Satellite space telescope, showing that there were no other planets around HD 118203 larger than twice the size of Earth, and therefore not massive enough to be relevant for studying the dynamics of the system,” said Julia Sierzputowska – an astronomy student and co-author of the study.

By 2023, the team obtained solid data of a Super Jupiter with a wide orbit, demonstrating that HD 118203 was a hierarchical planetary system. Said Prof. Maciejewski:

“Patience pays off. The new observations collected in March 2023 proved crucial in determining the planet’s orbital parameters. Moreover, because it takes a planet several years to orbit its star, we were able to combine our Doppler observations with available astrometric measurements to unambiguously determine its mass. This allowed us to build a complete model of this planetary system and study its dynamical behaviour.”

Astronomers from the NCU have discovered a new planet in the constellation Ursa Major. Credit: Andrzej Romanski

The configuration is peculiar, where one planet orbits closely with its star (forming a pair) while a second orbits them wide enough to form another pair with the first one. While both planets are massive and have rather elongated orbits, their mutual gravitational influence does not destabilize the system over the course of eons. According to their study, this is due to the effects of General Relativity, which prevents the planets from constantly changing the shape of their orbits and orientation in space.

This makes HD 118203 one of only a handful of hierarchical systems known to astronomers, which will help address theories of how massive planets form. This will, in turn, allow astronomers to learn more about the formation and evolution of the gas giants in our Solar System – Jupiter, Saturn, Uranus, and Neptune. The international team also plans to keep gathering data on this system in the hopes of finding additional exoplanets.

Further Reading: NCU News, Astronomy & Astrophysics

The post Astronomers Have Found a Star with a Hot Jupiter and a Cold Super Jupiter in Orbit appeared first on Universe Today.

Some lizards dive into streams to escape predators, and a specialised bubble-breathing technique enables them to stay submerged for up to 18 minutes

In February 2016, scientists at the Laser Interferometer Gravitational-wave Observatory (LIGO) confirmed they made the first-ever detection of gravitational waves (GWs). These events occur when massive objects like neutron stars and black holes merge, sending ripples through spacetime that can be detected millions (and even billions) of light-years away. Since the first event, more than 100 GW events have been confirmed by LIGO, the Advanced VIRGO collaboration, and the Kamioka Gravitational Wave Detector (KAGRA).

Moreover, scientists have found numerous applications for GW astronomy, from probing the interiors of supernovae and neutron stars to measuring the expansion rate of the Universe and learning what it looked like one minute after the Big Bang. In a recent study, an international team of astronomers proposed another application for binary black hole (BBH) mergers: using the earliest mergers in the Universe to probe the first generation of stars (Population III) in the Universe. By modeling how the events evolved, they determined what kind of GW signals the proposed Einstein Telescope (ET) could observe in the coming years.

The study was led by Boyuan Liu, a postdoctoral researcher at the Center for Astronomy of Heidelberg University (ZAH) and a member of the Excellence Cluster STRUCTURES program. He was joined by colleagues from the ZAH and the Institut für Theoretische Astrophysik at Heidelberg University, the Cambridge Institute of Astronomy, the Institute for Physics of Intelligence, the Institut d’Astrophysique de Paris, the Centre de Recherche Astrophysique de Lyon, the Gran Sasso Science Institute (GSSI), the Kavli Institute for Cosmology, the Weinberg Institute for Theoretical Physics, and multiple universities.

From Cosmic Dark to Dawn

Population III stars are the first to have formed in the Universe, roughly 100 to 500 million years after the Big Bang. At the time, hydrogen and helium were the most plentiful forms of matter in the Universe, leading to stars that were very massive and had virtually no metals (low metallicity). These stars were also short-lived, lasting only 2 to 5 million years before they exhausted their hydrogen fuel and went supernova. At this point, the heavier elements created in their cores (lithium, carbon, oxygen, iron, etc.) dispersed throughout the cosmos, leading to Population II and I stars with higher metallicity content.

Astronomers and cosmologists refer to this period as “Cosmic Dawn” since these first stars and galaxies ended the “Cosmic Dark Ages” that preceded it. As Liu explained to Universe Today via email, the properties of Pop III stars were sensitive to the peculiar conditions of the Universe during Cosmic Dawn, which were very different from the present-day conditions. This includes the presence of Dark Matter Haloes, which scientists believe were vital to the formation of the first galaxies:

“The timing of Pop III star formation reflects the pace of early structure formation, which can teach us about the nature of dark matter and gravity. In the standard cosmology model, cosmic structure formation is bottom-up, starting from small halos, which then grow by accretion and mergers to become larger halos. Pop III stars are expected to be massive (> 10 solar masses, reaching up to 1 million solar masses, while present-day stars have an average mass of ~ 0.5 solar masses). So, many of them will explode as supernovae or become massive black holes (BHs) when they run out of fuel for nuclear fusion.”

These Pop III black holes are further believed to be where the first supermassive black holes (SMBHs) in the Universe came from. As astronomers have demonstrated, SMBHs play an important role in the evolution of galaxies. In addition to assisting in the formation of new stars and encouraging galaxy formation in the early Universe, they are also responsible for shutting down star formation in galaxies ca. 2 to 4 billion years after the Big Bang, during the epoch known as “Cosmic Noon.” The growth of these black holes and the UV radiation emitted by Pop III stars reionized the neutral hydrogen and helium that permeated the early Universe.

This led to the major phase transition that ended the Cosmic Dark Ages (ca. 1 billion years after the Big Bang), allowing the Universe to become “transparent” as it is today. However, as Liu stated, how this process started remains unclear:

“Generally speaking, Pop III stars mark the onset of cosmic evolution from a starless (boring) state to the current state with rich phenomena (reionization, diverse populations of galaxies with different masses, morphologies, and compositions, andquasars powered by accreting supermassive BHs). To understand this complex evolution, it isessential to characterize its initial phase dominated by Pop III stars.”

Probing the Early Universe

The confirmation of gravitational waves (GW) was revolutionary for astronomers, and many applications have since been proposed. In particular, scientists are eager to study the primordial GWs created by the Big Bang, which will be possible with next-generation GW detectors like the Laser Interferometer Space Antenna (LISA). As Liu explained, existing GW detectors are mostly dedicated to studying binary black hole (BBH) mergers. The same is true of detectors expected to be built in the near future. Said Liu:

“The GW emission from a BH binary is stronger when they are closer. The GW emission carries away energy and angular momentum from the system such that the two BHs will get closer over time and eventually merge. We can only detect the GW signal at the final stage when they are about to merge. The time taken to reach the final stage is highly sensitive to the initial separation of the BHs. Basically, they have to start close (e.g., less than ~ 10% of the earth-sun distance for BHs below 10 solar masses) to merge within the current age of the Universe to be seen by us.”

The question is, how do two black holes get so close to each other that they will eventually merge? Astronomers currently rely on two evolutionary “channels” (sets of physical processes working together) to model this process: isolated binary stellar evolution (IBSE) and nuclear star cluster-dynamical hardening (NSC-DH). As Liu indicated, the resulting BBH mergers have distinct features in their merger rate and properties, depending on the channel they follow. They contain valuable information about the underlying physical processes.

“Knowledge of evolution channels is necessary to extract such information to fully utilize GWs as a probe for astrophysics and cosmology,” he added.

Modeling BBH Evolution

To determine how black holes come to form binaries that will eventually merge, the team combined both channels into a single theoretical framework based on the semianalytical model Ancient Stars and Local Observables by Tracing Halos (A-SLOTH). This model is the first publicly available code that connects the formation of the first stars and galaxies to observations. “In general, A-SLOTH follows the thermal and chemical evolution of gas along the formation, growth, and mergers of dark matter halos, including star formation and the impact of stars on gas (stellar feedback) at the intermediate scale of individual galaxies/halos,” said Liu.

Current operating facilities in the global network and their planned expansion. Credit: Caltech/MIT/LIGO Lab

They also used the Stellar EVolution for N-body (SEVN) code to predict how stellar binaries evolve into BBHs. They then modeled the orbit of each BBH in their respective dark matter halos and during halo mergers, which allowed them to predict when some BBHs will merge. In other cases, BBHs travel to the center of their galaxies and become part of a nuclear star cluster (NSC), where they are subject to disruptions, ejections, and hardening by gravitational scattering. From this, they followed the evolution of internal binary orbits to the moment of merger or disruption.

Next-Generation Observatories

As Lui explained, their results had significant theoretical and observational implications:

“On the theory side, my work showed that the isolated binary evolution channel dominates at high redshifts (less than 600 million years after the Big Bang) and the merger rate is sensitive to the formation rate and initial statistics of Pop III binary stars. In fact, the majority (> 84%) of BH binaries, especially the most massive ones, are initially too wide to merge within the age of the Universe if they evolve in isolation. But a significant fraction (~ 45 – 64%) of them can merge by dynamical hardening if they fall into NSCs. These predictions are useful for the identification and interpretation of merger origins in observations.”

In terms of observational results, they found that the predicted detection of Pop III BBH mergers is not likely to be discernible by current instruments like LIGO, Advance Virgo, and KAGRA, which generally observe BBH mergers closer to Earth. “[A]ltough Pop III mergers can potentially account for a significant fraction of the most massive BH mergers detected so far (with BHs above 50 solar masses),” said Liu. “It is difficult to learn much about Pop III stars and galaxies in the early Universe from the existing data because the sample size of detected massive mergers is too small.”

However, next-generation detectors like the Einstein Telescope will be more efficient in detecting these distant sources of GWs. Once completed, the ET will allow astronomers to explore the Universe through GWs back to the Cosmic Dark Ages, providing information on the earliest BBH mergers, Pop III stars, and the first SMBHs. “My model predicts that the Einstein Telescope can detect up to 1400 Pop III mergers per year, offering us much better statistics to constrain the relevant physics.”

The paper that describes their findings recently appeared online and is being reviewed for publication in the Monthly Notices of the Royal Astronomical Society.

Further Reading: arXiv

The post Future Gravitational Wave Observatories Could See the Earliest Black Hole Mergers in the Universe appeared first on Universe Today.

In a survey of thousands of people, respondents underestimated the massive difference between the carbon footprints of the wealthiest and poorest individuals – and that’s bad for climate policy