Latest news with #cosmology
Yahoo
2 days ago
- Science
- Yahoo
The world started with a ‘bang' but will end in a scary ‘big crunch' — and scientists think they know when that will be
Our humble blue planet came into being with the Big Bang — the sudden expansion of the universe outwards. Now, according to astrophysicists and cosmologists, Earth and all of its celestial siblings will likely be swallowed back into the super-small singularity they came from, in what is known as the 'big crunch' theory. Alarming as it sounds, physicists say there's no reason to fret just yet. According to leading experts on the matter, the big crunch theory supposes that the universe will eventually stop expanding and everything will be pulled back together. Cosmologists at Cornell University predict that the big crunch is billions of years away —19.5 to be exact. Henry Tye, a lead researcher at the institution, suggested that the big crunch will begin in 11 billion years, and will take another 8.5 billion years to conclude. Supposing humanity is still around billions of years from now, scientists say it's unlikely we would notice any distinct changes while the big crunch takes place. 'Intelligent civilizations at the scales of solar systems or even galactic scales would not notice any obvious phenomenon because these changes happen at much larger cosmological scales,' Dr Hoang Nhan Luu, a researcher at the Donostia International Physics Center, explained to the Daily Mail. However, one of the warning signs would be a rising cosmic temperature. In a few billion years, it's probable that the universe, including all of its major celestial bodies, will be the same temperature as the surface of the sun. 'Needless to say, all humans will burn up in the furnace of this cosmic hell,' Avi Loeb, an astrophysicist at Harvard University, told the Daily Mail. The theory has been swirling among academic circles for decades, but fell out of favor among some camps of researchers several decades back. However, after dark energy — a repellent force that pushes things in the universe apart — was discovered in the '90s and research has progressed, it seems more and more experts are reevaluating their stances. Mustapha Ishak-Boushaki, an astrophysicist at the University of Texas at Dallas, told Discover Magazine that dark matter research has revealed that the universe isn't slowing down, but rather, its expansion is accelerating less, and eventually, it will come to a slow halt. 'To survive, human beings have to move to the edge of our solar system or beyond. We have a few billion years' time to prepare for that trip,' Tye explained to the Daily Mail. The big crunch theory spells trouble for humanity in several ways, but it's far from the first scary-sounding phenomenon that our planet has undergone. Earth's magnetic poles reversed 780,000 years ago. Researchers at the Helmholtz Centre for Geosciences in Germany created a soundscape of the geological gymnastics routine, which they dubbed a 'disharmonic cacophony.' Solve the daily Crossword
Gizmodo
14-07-2025
- Science
- Gizmodo
Dozens of ‘Ghost Galaxies' Are Orbiting the Milky Way, Astronomers Suspect
The Lambda Cold Dark Matter (LCDM) theory suggests that most galaxies are low-mass dwarf galaxies, many of which orbit larger galaxies like the Milky Way. More broadly, the LCDM represents our best understanding of how the universe works. But there's a problem. According to the theory, the Milky Way should have significantly more satellite galaxies than scientists have observed with telescopes and predicted with computer simulations. By combining the highest-resolution supercomputer simulations to date with new mathematical modeling, cosmologists at Durham University in the U.K. suggest there might be up to 100 previously unidentified galaxies orbiting the Milky Way, effectively tracking down our galaxy's 'missing' companions. If future telescopes detect these galaxies directly, it would further bolster the reliability of the LCDM theory, the most widely accepted standard model of large-scale cosmology. 'If the population of very faint satellites that we are predicting is discovered with new data, it would be a remarkable success of the LCDM theory of galaxy formation,' Carlos Frenk, a cosmologist from Durham University, said in a university statement. 'Using the laws of physics, solved using a large supercomputer, and mathematical modelling we can make precise predictions that astronomers, equipped with new, powerful telescopes, can test. It doesn't get much better than this.' According to the LCDM theory, 5% of the universe is made up of atoms, 25% of cold dark matter (CDM), and 70% of dark energy. Furthermore, galaxies are born within assemblages of dark matter called halos. Prior to this new approach, the researchers claim that even the best cosmological simulations were unable to study very faint galaxies or the evolution of their dark matter halos over billions of years. The simulations basically lost the halos of the consequently 'orphaned' galaxies. According to the ongoing research presented at the Royal Astronomical Society's National Astronomy Meeting earlier this month, Frenk and his colleagues' novel technique indicates the presence of faint halos of dark matter potentially hosting orphaned satellite galaxies. They estimated the abundance, distribution, and properties of these 'ghost' galaxies (as they're also called in another Durham University press release) and suggested that the Milky Way's gravity may have stripped them almost completely of said dark matter halos as well as their stellar mass. 'We know the Milky Way has some 60 confirmed companion satellite galaxies, but we think there should be dozens more of these faint galaxies orbiting around the Milky Way at close distances,' said Durham University's Isabel Santos-Santos, also a cosmologist and co-lead researcher along with Frenk. 'Observational astronomers are using our predictions as a benchmark with which to compare the new data they are obtaining. One day soon we may be able to see these 'missing' galaxies, which would be hugely exciting and could tell us more about how the Universe came to be as we see it today.' While the universe still hides innumerable mysteries, it seems like sometimes we're on the right track.
WIRED
14-07-2025
- Science
- WIRED
The Structure of Ice in Space Is Neither Order nor Chaos—It's Both
Jul 14, 2025 5:00 AM Long thought to be completely disordered, space ice appears to have some crystallized regions, new research suggests. Illustration: AllIce is a key component in the universe. There are frozen water molecules on comets, moons, exoplanets, and in your drink as you cool off from the summer heat. However, under the microscope, not all ice is the same, even though it is made of the same components. The internal structure of Earth's ice is a cosmological oddity. Its molecules are arranged in geometric structures, usually hexagons that repeat each other. Ice on Earth forms this way due to the temperature and pressure of the our planet: water here freezes slowly, and this allows its molecules to arrange themselves into crystals. But ice that forms in space is different because of the conditions—the water exists in a vacuum and is subject to extreme temperatures. Space ice, as a result, is believed to be amorphous, lacking a distinct organizational structure like on Earth. An illustration of the ordered molecular structure of water ice on Earth. GETTY IMAGES This presents a challenge for scientists trying to understand the formation of planets and the generation of life. Not fully understanding the dynamics of amorphous ice in space has knock-on effects. For instance, not knowing exactly how space water freezes makes it difficult to estimate the proportion of water in other solar systems. Researchers are therefore studying space ice to gain a better understanding of how frozen water behaves away from Earth. Ice samples from comets, asteroids, and other solar system debris would be helpful, but until these can be captured, scientists are trying to understand space ice with computer models and simulations of ice on Earth. The more they study it, the more surprises it reveals. A recent report, published in the journal Physical Review B, posits that the amorphous ice that abounds in the universe does have some kind of order. The paper theorizes it is likely made up of structured fragments—crystallized regions, as on Earth, but only about 3 nanometers wide—surrounded by chaos. A simulation of space ice. The white fragments are ordered molecules in crystalline structures while the blue parts are disordered molecules. Illustration: Courtesy of the ICE Group, University of Cambridge To reach this conclusion, the team first ran computer models of water molecules subjected to temperature changes at different rates, simulating the creation of ice in space. They then compared this with the results of lab experiments to produce actual amorphous ice. Water vapor was passed over an extremely cold slab to become ice, with no liquid state occurring in between, a process similar to what happens in a planetary system at birth. A partially amorphous material was produced, whose structure most closely matched a simulation from the models that comprised 20 percent crystalline material and 80 percent amorphous ice. 'We now have a good idea of what the most common form of ice in the universe looks like at the atomic level,' said Michael B. Davies, part of the ICE Group at the University of Cambridge and a coauthor of the study, in a statement. Knowing the structure of space ice is important for interrogating the speculative idea of panspermia, a hypothesis that life on Earth originated through compounds or 'seeds' of life arriving on our planet from space. If space ice is amorphous and of low density, then building blocks for life could potentially have been carried inside. If, instead, there are lots of crystalline parts, then there is less likelihood (because of less space) of this having occurred. This story originally appeared on WIRED en Español and has been translated from Spanish.
Gizmodo
13-07-2025
- Science
- Gizmodo
Astronomers Detect a Black Hole Merger That's So Massive It Shouldn't Exist
Gravitational waves—ripples in space-time caused by violent cosmic events—travel at the speed of light in every direction, eventually fading out like ripples in water. But some events are so destructive and extreme that they create disturbances in spacetime more like powerful waves than small ripples, with enough energy to reach our own detectors here on Earth. Today, the LIGO Collaboration announced the detection of the most colossal black hole merger known to date, the final product of which appears to be a gigantic black hole more than 225 times the mass of the Sun. Much about this signal, designated GW231123, contradicts known models for stellar evolution, sending physicists scrambling to apprehend how such a merger was even possible. LIGO, or the Laser Interferometer Gravitational-wave Observatory, made physics history in 2015 by detecting gravitational waves for the first time, capturing the cosmological echo of two colliding black holes. Since its Nobel-winning discovery, the LIGO Collaboration, an international partnership between LIGO and Virgo and KAGRA in Italy and Japan, respectively, has continued its meticulous surveillance of the galaxy. The collaboration has detected numerous signals from neutron stars, supernovas, and some 300 black hole mergers. But GW231123, first observed on November 23, 2023, seems to be an unprecedented beast of a black hole merger. Two enormous black holes—137 and 103 times the mass of the Sun—managed to keep it together despite their immense combined mass, spinning at 400,000 times the speed of Earth's rotation to form an ever bigger black hole. To put its size into perspective, the previous record holder for such a merger, GW190521, is roughly 140 times the mass of the Sun. Considering the gravitationally chaotic nature of black hole environments, with their pushes and pulls, it's remarkable that this merger was stable enough for the resulting gravitational waves to reach LIGO, which detected the signals for a duration of 0.1 seconds. Such episodes should be 'forbidden' according to standard evolution models, said Mark Hannam, LIGO member and physicist at Cardiff University, in a statement. 'One possibility is that the two black holes in this binary formed through earlier mergers of smaller black holes,' he surmised. 'This is the most massive black hole binary we've observed through gravitational waves, and it presents a real challenge to our understanding of black hole formation.' 'The black holes appear to be spinning very rapidly—near the limit allowed by Einstein's theory of general relativity,' explained Charlie Hoy, LIGO member and physicist at the University of Portsmouth in England, in the same release. 'That makes the signal difficult to model and interpret. It's an excellent case study for pushing forward the development of our theoretical tools.' Scientists will present their findings about GW231123 next week at the 24th International Conference on General Relativity and Gravitation (GR24) and the 16th Edoardo Amaldi Conference on Gravitational Waves, held jointly as the GR-Amaldi meeting in Glasgow, U.K. Following that, the data will be out for public scrutiny, kicking off the race to unravel GW231123's mystery—though it's unlikely we'll have a clear answer any time soon. 'It will take years for the community to fully unravel this intricate signal pattern and all its implications,' added Gregorio Carullo, also a LIGO member and physicist at the University of Birmingham, England. 'Despite the most likely explanation remaining a black hole merger, more complex scenarios could be the key to deciphering its unexpected features. Exciting times ahead!' Physicists first conceived of gravitational waves as early as the late 19th century, but the idea gained popular momentum thanks to Albert Einstein. As one of the few observational methods that doesn't need light to 'see' cosmic phenomena, gravitational waves are unmatched in their potential for helping humanity uncover the many mysteries of black holes, ancient stars, and even dark matter. So, indeed—exciting times ahead!
Yahoo
13-07-2025
- Science
- Yahoo
Scientists Say Earth May Be Trapped Inside a Huge, Strange Void
Astronomers who examined the sound waves from the Big Bang say that the Earth — and the entire Milky Way galaxy we call home — could be trapped in a huge void billions of light years across. Their study, which was just presented at the Royal Astronomical Society's National Astronomy Meeting in the UK, could solve one of cosmology's greatest mysteries: the Hubble tension, or why the older universe appears to be expanding more slowly than younger regions. "The Hubble tension is largely a local phenomenon, with little evidence that the expansion rate disagrees with expectations in the standard cosmology further back in time," Indranil Banik, a cosmologist from the University of Portsmouth who led the research, said in a statement about the work. "So a local solution like a local void is a promising way to go about solving the problem." Our universe is expanding at an accelerated rate, but precisely what rate is a matter of intense debate. When astronomers analyze the cosmic microwave background, the light leftover from the Big Bang and the oldest light in the universe, the rate is slower compared to that derived from observations in the nearby universe of Type Ia supernovas and luminous, pulsing stars known as Cepheids. The discrepancy has become undeniable, and its implications are so profound that it's been dubbed a "crisis in cosmology." Is our understanding of the universe wrong? Is there some new physics we are yet unaware of? But this latest research could pump the brakes a little. If the Earth happens to be near the center of a low density "void" in space, approximately a billion light years in radius and roughly 20 percent below the universe's average density, that could neatly explain the discrepancy. Banik explains that such a region "would cause matter to be pulled by gravity toward the higher-density exterior of the void, leading to the void becoming emptier with time." "As the void is emptying out," he continues, "the velocity of objects away from us would be larger than if the void were not there. This therefore gives the appearance of a faster local expansion rate." The idea of a local void has been floated before. But this latest work adds credence to the theory by analyzing baryon acoustic oscillations (BAO), or as the researchers call it, the "sound of the Big Bang" — emanations produced as the uniform sea of hot matter that formed from the Big Bang repeatedly contracted and then expanded in a tug of war with gravity, before eventually cooling. "These sound waves traveled for only a short while before becoming frozen in place once the universe cooled enough for neutral atoms to form," Banik said, allowing astronomers to use them as a "standard ruler" to measure cosmos. If this void exists, Banik argues, then it would distort the BAO in a way that we could measure. After analyzing all BAO measurements taken over the last 20 years, that's exactly what Banik says he's found. The biggest problem that this theory runs into, however, is that it defies our understanding of the universe's structure: at the largest scales, it should appear uniform and evenly distributed. A region billions of light years across that's somehow less dense than everything around it is quite clearly in violation of that. Nonetheless, Banik plans to test his local void model with other methods of estimating the universe's expansion. More on space: Mysterious Object Headed Into Our Solar System Is Coming From the Center of the Galaxy
