The Hubble Space Telescope has captured imagery of the R Aquarii binary star system from 2014–2023. The images have been time-lapsed here to show the evolution of the region.
Credit: NASA, ESA, M. Stute, M. Karovska, D. de Martin \& M. Zamani (ESA/Hubble) | edited by Space.com.
Music: You Want Dark Tunes? by Ave Air / courtesy of http://www.epidemicsound.com
Lunar rock and zircon ages were reset by a remelting event driven by the Moon’s orbital evolution, reconciling existing discrepancies in estimates for the formation time of the Moon and the crystallization time of its magma ocean.
Astronomers have discovered a new way to study black holes, the mysterious cosmic entities that destroy anything in their path. By observing X-ray bursts from a star being torn apart by a black hole, researchers calculated the black hole’s spin rate for the first time using X-rays. The black hole was found spinning at nearly 50 percent of the speed of light. This research, published in Science, opens new possibilities for understanding black holes’ behavior and evolution.
The discovery dates back to November 2014, when astronomers observed a supermassive black hole in a galaxy 300 million light years away. This black hole ripped apart a star that had ventured too close, an event known as a tidal disruption flare. The flare generated intense bursts of X-rays that were visible from Earth. Since black holes themselves don’t produce many X-rays, researchers saw an opportunity to study this flare closely.
The course of evolution on Earth was altered by a series of severe environmental crises caused between 185 and 85 million years ago in the oceans, according to scientists.
The phenomenon, described as a ‘tag-team’ between the oceans and continents, severely harmed the marine life which existed during that phase and also changed the evolution course on our planet.
The oceanic anoxic events, as per the term given by the researchers, occurred when the dissolved oxygen in the water depleted to a critically low level.
Virginia Tech’s study traces early eukaryotic evolution, highlighting life’s diversification since 2 billion years ago.
Salt, or more precisely the sodium it contains, is very much a “Goldilocks” nutrient. Low sodium levels cause a drop in blood volume, which can have serious, sometimes deadly, health consequences. Conversely, too much salt can lead to high blood pressure and cardiovascular disease.
In modern America, where most people consume a high-salt diet, almost no one is in danger of having too little salt. However, given the critical importance of sodium for body and brain functions, evolution has developed a powerful drive to consume salt in situations where there is a deficiency.
Understanding the brain circuitry that controls salt appetite has proved elusive, but now a new study by University of Iowa researchers has identified the first and, thus far, only neurons necessary for salt appetite.
Which brings us to the big question: what about gravity?
This is something where we can’t be certain, as gravitation remains the only known force for which we don’t have a full quantum description. Instead, we have Einstein’s general relativity as our theory of gravity, which relies on a purely classical (i.e., non-quantum) formalism for describing it. According to Einstein, spacetime behaves as a four-dimensional fabric, and it’s the curvature and evolution of that fabric that determines how matter-and-energy move through it. Similarly it’s the presence and distribution of matter-and-energy that determine the curvature and evolution of spacetime itself: the two notions are linked together in an inextricable way.
Now, over on the quantum side, our other fundamental forces and interactions have both a quantum description for particles and a quantum description for the fields themselves. All calculations performed within all quantum field theories are calculated within spacetime, and while most of the calculations we perform are undertaken with the assumption that the underlying background of spacetime is flat and uncurved, we can also insert more complex spacetime backgrounds where necessary. It was such a calculation, for example, that led Stephen Hawking to predict the emission of the radiation that bears his name from black holes: Hawking radiation. Combining quantum field theory (in that case, for electromagnetism) with the background of curved spacetime inevitably leads to such a prediction.
Almost 300 binary mergers have been detected so far, indicated by their passing gravitational waves. These measurements from the world’s gravitational wave observatories put constraints on the masses and spins of the merging objects such as black holes and neutron stars, and in turn this information is being used to better understand the evolution of massive stars.
Thus far, these models predict a paucity of black hole binary pairs where each black hole has around 10 to 15 times the mass of the sun. This “dip or mass gap” in the mass range where black holes seldom form depends on assumptions made in the models; in particular, the ratio of the two masses in the binary.
Now a new study of the distribution of the masses of existing black holes in binaries finds no evidence for such a dip as gleaned from the gravitational waves that have been detected to date. The work is published in The Astrophysical Journal.
If all the world’s a stage and all the species merely players, then their exits and entrances can be found in the rock record. Fossilized skeletons and shells clearly show how evolution and extinction unfolded over the past half a billion years, but a Virginia Tech analysis extends the chart of life to nearly 2 billion years ago. The study is published in the journal Science.
The chart shows the relative ups and downs in species counts, telling scientists about the origin, diversification, and extinction of ancient life.
With this new study, the chart of life now includes life forms from the Proterozoic Eon, 2,500 million to 539 million years ago. Proterozoic life was generally smaller and squishier—like sea sponges that didn’t develop mineral skeletons —and left fewer traces to fossilize in the first place.
In their Review article earlier this year, Fedorenko, Ivanova & Regev (Fedorenko, E., Ivanova, A. A. & Regev, T. I. The language network as a natural kind within the broader landscape of the human brain. Nat. Rev. Neurosci. 25, 289–312 (2024))1 propose a functional separation between the core language network and other perceptual, motor and higher-level cognitive components of communication-related networks in the left hemisphere of the human brain. In the ‘Open questions and a way forward’1 section that ends their Review, the authors discuss the need for cross-species comparative research to disentangle how these brain networks came to support human language. Here, we suggest that the authors’ functional separation of a core language network and other components in the human brain is grounded in the evolution of two separate structural networks within primate brains.
Fedorenko and colleagues describe the core language network as left-lateralized, and involving the middle frontal gyrus (MFG), inferior frontal gyrus (IFG), superior temporal gyrus (STG) and middle temporal gyrus (MTG). Perceptual and motor systems for speech are defined as separate subsystems located in auditory cortex and speech perception areas in the STG and motor cortex and motor planning areas1, respectively. Importantly, these functionally defined key brain areas are known to be structurally connected via dorsally and ventrally located white-matter fibre tracts, which guarantee the information flow between areas. In humans, two separate dorsal pathways that provide structural connections have been identified for two distinct networks2,3 (Fig. 1).
