Latest news with #KM3NeT
Gizmodo
5 days ago
- Business
- Gizmodo
Physicists Propose Cheaper Alternative to Particle Colliders: Supermassive Black Holes
A new study from Johns Hopkins University suggests that supermassive black holes—those cosmic behemoths lurking at the centers of galaxies—might already be generating the kinds of high-energy particle collisions researchers have spent decades trying to recreate here on Earth. Published today in Physical Review Letters, the study proposes that certain spinning black holes could serve as natural particle accelerators, rivaling or even exceeding the capabilities of the Large Hadron Collider (LHC). That's a big deal, especially as funding for fundamental physics research grows increasingly scarce in the United States, and plans for next-generation colliders stretch far into the future. For about a decade, experts have theorized that supermassive black holes could do this, co-author Andrew Mummery, a theoretical physicist at the University of Oxford, told Gizmodo. But his study attempted to validate this theory by looking for naturally-occurring scenarios that would give rise to a black hole's supercollider-like behavior. Understanding how this happens could provide a new avenue for research on dark matter and other elusive particles. 'One of the great hopes for particle colliders like the Large Hadron Collider is that it will generate dark matter particles, but we haven't seen any evidence yet,' explained co-author Joseph Silk, an astrophysicist at Johns Hopkins University, the University of Oxford, and the Institute of Astrophysics in Paris, in a Johns Hopkins release. 'That's why there are discussions underway to build a much more powerful version, a next-generation supercollider,' Silk said. 'But as we invest $30 billion and wait 40 years to build this supercollider—nature may provide a glimpse of the future in super massive black holes.' At the LHC, protons are smashed together at near-light speeds to uncover the building blocks of reality—and hopefully, to catch a glimpse of dark matter, the mysterious stuff that makes up about 85% of the universe's mass. But it turns out black holes might already be producing these elusive particles in the wild. Some supermassive black holes spin so rapidly that they can fling out jets of plasma at astonishing speeds. In their new study, Mummery and Silk modeled what happens near the edge of these spinning monsters, where violent gas flows can whip particles into chaotic collisions, much like a human-built collider does. 'Some particles from these collisions go down the throat of the hole and disappear forever,' Silk said, 'But because of their energy and momentum, some also come out, and it's those that come out which are accelerated to unprecedentedly high energies.' These ultra-energetic particles zipping through space could, in theory, be picked up by Earth-based observatories like IceCube in Antarctica or the KM3NeT telescope beneath the Mediterranean Sea, both of which already detect ghostly particles called neutrinos. Earlier this year, KM3NeT researchers announced the detection of the most energetic neutrino yet, a potential step forward in understanding the behavior of these ephemeral and energetic particles. Equipped with a deeper understanding of how these high-energy particles might form at the edges of supermassive black holes, Mummery now aims to investigate their nature. Figuring out what, exactly, escapes from these cosmic voids could offer a cost-effective, naturally occurring complement to traditional colliders. The approach could yield a new path toward uncovering the nature of dark matter.
Yahoo
16-05-2025
- Science
- Yahoo
Why scientists are so excited about the highest-energy 'ghost particle' ever seen
When you buy through links on our articles, Future and its syndication partners may earn a commission. Earlier this year, an underwater detector in the Mediterranean Sea found the most energetic neutrino to date. And scientists are still talking about it because, well, this discovery could be a really big deal. Not only could this neutrino, also known as a "ghost particle," have been fleeing a gamma-ray burst or a supermassive black hole, but it could also have been produced by an ultra-powerful cosmic ray interacting with the cosmic microwave background (CMB). That latter bit which we'll get to soon, could be huge. Moreover, the detector that pinpointed this particle isn't even totally built yet — once put together, who knows what it can accomplish. "We're excited to have observed this event and we're hungry and curious for more," KM3NeT's spokesperson, Paul de Jong of the University of Amsterdam, told For some background, the neutrino was detected on February 13, 2023 by the European Union-funded KM3NeT, the Cubic Kilometre Neutrino Telescope. Neutrinos are ghostly particles because they have very little mass and rarely interact with other forms of matter, making them very difficult to detect. Trillions of neutrinos are passing through your body every second, yet you cannot tell. Scientists have to be patient to spot even one neutrino. Modern neutrino detectors are placed in water, and particularly in the dark. Sometimes that water is held in a tank, as was the case with the Sudbury Neutrino Observatory in Canada, as well as with Super-Kamiokande in Japan. Other times, that water is frozen in the ground, as in the case of the IceCube Neutrino Observatory at the South Pole. But it's also possible for neutrino detectors to literally be dipped into the sea, as is the case with KM3NeT, which extends as deep as 2.17 miles (3.5 kilometers) below the waves. The reason water is so important is that, occasionally, a neutrino will interact with a molecule of water. The energies involved can be so great that the collision smashes the water molecule apart into a bunch of daughter nuclei and particles, specifically muons. The muons travel quickly, almost as fast as light in a vacuum, and definitely faster than light through water — the refractive index of water slows light down to approximately 738,188,976 feet per second (225,000,000 meters per second) compared to 983,571,056 feet per second (299,792,458 meters per second) in a vacuum. Because the muons travel faster than light in water, they give off the equivalent of a sonic boom in the form of a flash of light. This light is called Cherenkov radiation. KM3NeT consists of two detectors. The first, called ORCA, is 8,038 feet (2,450 meters) deep off the coast of France and is designed to study how neutrinos oscillate between different types of neutrinos. The other, aka the detector that spotted the new energetic neutrino — which has been catalogued as KM3-230213A — is called ARCA and is located off the coast of Sicily. Both ARCA and ORCA are still under construction. When complete, ARCA will feature 230 vertical detection lines descending into the sea. Each will be lined with 18 optical modules containing 31 photomultiplier tubes that can spot flashes of Cherenkov radiation in the darkness at those depths. At the time that ARCA detected KM3-230213A, only 21 of its detection lines were in operation. The muon ARCA detected had an energy of 120 PeV (1,000 trillion, or quadrillion, electronvolts), which implies the neutrino that produced it must have had a record-breaking energy of 220 PeV. This is 100 quadrillion times more energetic than visible-light photons, and 30 times more energetic than the neutrino that held the previous energy record. Muons can travel several miles through the sea before being absorbed, and KM3NeT detected the muon traveling horizontally rather than straight down to the sea floor. "The horizontal direction on the muon is very relevant," said de Jong. Muons can also be formed in cosmic-ray spallation, wherein a cosmic ray enters Earth's atmosphere and collides with a molecule or atom, smashing it apart into a shower of subatomic particles. Muons formed in this manner can either reach the surface or enter the ocean while traveling straight down — not horizontally. To have been moving horizontally, the muon must have instead "been created close to the detector, and the only realistic scenario is that it was created by a high-energy neutrino," said de Jong. A neutrino of 220 PeV is unprecedented. No environment or object known in our Milky Way galaxy could have produced a neutrino with so much energy. That means its origin must be extragalactic, perhaps created in the violence of a star exploding and producing a gamma-ray burst, or a supermassive black hole ripping a star or gas cloud to shreds with its titanic gravitational tidal forces. Because neutrinos are not deflected by magnetic fields or by gravity, their direction of travel leads back to their source. "The muon direction is almost identical to the direction of the original neutrino, so we can play the game of pointing it back to its cosmic origin," said de Jong. That origin is somewhere in the direction of the constellation of Orion, the Hunter. However, while there are numerous active galaxies with supermassive black holes in that region, none of them was displaying activity at the time that could explain the neutrino, nor was a gamma-ray burst detected from that direction at that time. But another intriguing possibility is that KM3-230213A is the first "cosmogenic" neutrino to be discovered, produced when an ultra-high-energy cosmic ray smashes into a photon belonging to the cosmic microwave background, which is the residual light released 379,000 years after the Big Bang. It would take an extremely energetic cosmic ray to be able to produce a neutrino like KM3-230213A. Cosmic rays in excess of 100,000 PeV have been detected by the likes of the Pierre Auger Observatory in Argentina. Their origins are uncertain, but, in theory every time such a cosmic ray encounters a CMB photon, the collision can produce neutrinos as energetic as KM3-230213A. The greater the cosmic-ray energy, the greater its interaction cross-section, meaning it is more likely to interact with CMB photons. The constant interactions between cosmic rays and CMB photons slows the cosmic ray, limiting their kinetic energy. This is called the Greisen–Zatsepin–Kuzmin (GZK) limit. Related Stories: — Scientists detect highest-energy ghost particle ever seen — where did it come from? — Black holes snacking on small stars create particle accelerators that bombard Earth with cosmic rays — Einstein wins again! Quarks obey relativity laws, Large Hadron Collider finds The possibility of a cosmogenic neutrino excites de Jong. "It would be the very first observation of a cosmogenic neutrino, and it would be the first confirmation of the GZK cut-off outside charged cosmic rays — and even there the proof is ambiguous," he said. Furthermore, the energy of cosmogenic neutrinos can reveal the properties of these ultra-high-energy cosmic rays. This parameter is key for discovering whether such phenomena are made of just protons or heavier atomic nuclei — and, therefore, what produces them. Although KM3-230213A was the only extremely high energy neutrino detected by KM3NeT, there will undoubtedly be many more passing through Earth that go undetected. Does KM3NeT's early detection with ARCA bode well for finally being able to detect such neutrinos more regularly? "We certainly hope so!" said de Jong. "But realistically, other experiments such as IceCube have been taking data for longer and have not observed such an event, so we could simply have been lucky." The discovery was described in a paper published on Feb. 12 in the journal Nature.
Yahoo
12-03-2025
- Science
- Yahoo
A single particle in the deep sea could prove Stephen Hawking right about the early universe
When you buy through links on our articles, Future and its syndication partners may earn a commission. Five decades ago, famed astrophysicist Stephen Hawking theorized that the Big Bang may have flooded the universe with tiny black holes. Now, researchers believe they may have seen one explode. In Feb. 2025, the European collaboration KM3NeT — which consists of underwater detectors off the coasts of France, Italy and Greece — announced the discovery of a stupendously powerful neutrino. This ghostly particle had an energy of around 100 PeV — over 25 times more energetic than the particles accelerated in the Large Hadron Collider, the world's most powerful atom smasher. Physicists have struggled to come up with an explanation for such an energetic neutrino. But now, a team of researchers who were not involved in the original detection have proposed a surprising hypothesis: The neutrino is the signature of an evaporating black hole. The team described their proposal in a paper that was uploaded to the arXiv database and has not been peer-reviewed yet. In the 1970s, Hawking realized that black holes aren't entirely black. Instead, through complex interactions between the black hole event horizon and the quantum fields of space-time, they can emit a slow-but-steady stream of radiation, now known as Hawking radiation. This means black holes evaporate and eventually disappear. In fact, as the black hole gets smaller, it emits even more radiation, until it essentially explodes in a firestorm of high-energy particles and radiation — like the neutrino spotted by the KM3Net collaboration. Related: Stephen Hawking's black hole radiation paradox could finally be solved — if black holes aren't what they seem But all known black holes are very large — at least a few times the mass of the sun, and often significantly larger. It will take well over 10^100 years for even the smallest known black holes to die. If the KM3NeT neutrino is due to an exploding black hole, it has to be much smaller — somewhere around 22,000 pounds (10,000 kilograms). That's about as heavy as two fully grown African elephants, compressed into a black hole smaller than an atom. The only known potential way to produce such tiny black holes is in the chaotic events of the early Big Bang, which may have flooded the cosmos with "primordial" black holes. The smallest primordial black holes produced in the Big Bang would have exploded long ago, while larger ones might persist to the present day. Unfortunately, a 22,000-pound black hole should not survive all the way from the Big Bang to the present day. But the authors pointed out that there might be an additional quantum mechanism — known as "memory burden" — that allows black holes to resist decay. This would allow a 22,000-pound black hole to survive for billions of years before it finally exploded, sending a high-energy neutrino toward Earth in the process. RELATED STORIES —Unproven Einstein theory of 'gravitational memory' may be real after all, new study hints —'Cosmic Horseshoe' may contain black hole the size of 36 billion suns — one of the largest ever detected —Scientists may have just discovered 300 of the rarest black holes in the universe Primordial black holes might be an explanation for dark matter — the invisible substance that accounts for most of the matter in the universe — but so far, searches for them have turned up empty. This new insight may provide an intriguing clue. The researchers found that if primordial black holes of this mass range are abundant enough to account for all the dark matter, they should be exploding somewhat regularly. They estimated that if this hypothesis is correct, the KM3NeT collaboration should see another showstopping neutrino in the next few years. If that detection happens, then we may just have to radically rethink the way we approach dark matter, high-energy neutrinos and even the physics of the early universe.
Yahoo
12-03-2025
- Science
- Yahoo
A single particle in the deep sea could prove Stephen Hawking right about the early universe
When you buy through links on our articles, Future and its syndication partners may earn a commission. Five decades ago, famed astrophysicist Stephen Hawking theorized that the Big Bang may have flooded the universe with tiny black holes. Now, researchers believe they may have seen one explode. In Feb. 2025, the European collaboration KM3NeT — which consists of underwater detectors off the coasts of France, Italy and Greece — announced the discovery of a stupendously powerful neutrino. This ghostly particle had an energy of around 100 PeV — over 25 times more energetic than the particles accelerated in the Large Hadron Collider, the world's most powerful atom smasher. Physicists have struggled to come up with an explanation for such an energetic neutrino. But now, a team of researchers who were not involved in the original detection have proposed a surprising hypothesis: The neutrino is the signature of an evaporating black hole. The team described their proposal in a paper that was uploaded to the arXiv database and has not been peer-reviewed yet. In the 1970s, Hawking realized that black holes aren't entirely black. Instead, through complex interactions between the black hole event horizon and the quantum fields of space-time, they can emit a slow-but-steady stream of radiation, now known as Hawking radiation. This means black holes evaporate and eventually disappear. In fact, as the black hole gets smaller, it emits even more radiation, until it essentially explodes in a firestorm of high-energy particles and radiation — like the neutrino spotted by the KM3Net collaboration. Related: Stephen Hawking's black hole radiation paradox could finally be solved — if black holes aren't what they seem But all known black holes are very large — at least a few times the mass of the sun, and often significantly larger. It will take well over 10^100 years for even the smallest known black holes to die. If the KM3NeT neutrino is due to an exploding black hole, it has to be much smaller — somewhere around 22,000 pounds (10,000 kilograms). That's about as heavy as two fully grown African elephants, compressed into a black hole smaller than an atom. The only known potential way to produce such tiny black holes is in the chaotic events of the early Big Bang, which may have flooded the cosmos with "primordial" black holes. The smallest primordial black holes produced in the Big Bang would have exploded long ago, while larger ones might persist to the present day. Unfortunately, a 22,000-pound black hole should not survive all the way from the Big Bang to the present day. But the authors pointed out that there might be an additional quantum mechanism — known as "memory burden" — that allows black holes to resist decay. This would allow a 22,000-pound black hole to survive for billions of years before it finally exploded, sending a high-energy neutrino toward Earth in the process. RELATED STORIES —Unproven Einstein theory of 'gravitational memory' may be real after all, new study hints —'Cosmic Horseshoe' may contain black hole the size of 36 billion suns — one of the largest ever detected —Scientists may have just discovered 300 of the rarest black holes in the universe Primordial black holes might be an explanation for dark matter — the invisible substance that accounts for most of the matter in the universe — but so far, searches for them have turned up empty. This new insight may provide an intriguing clue. The researchers found that if primordial black holes of this mass range are abundant enough to account for all the dark matter, they should be exploding somewhat regularly. They estimated that if this hypothesis is correct, the KM3NeT collaboration should see another showstopping neutrino in the next few years. If that detection happens, then we may just have to radically rethink the way we approach dark matter, high-energy neutrinos and even the physics of the early universe.
Yahoo
19-02-2025
- Science
- Yahoo
A Detector at the Bottom of the Sea Found an Extraordinary Signal From the Unseen Universe
Neutrinos are arguably the most enigmatic particles in the universe, but scientists on Earth are getting better at detecting them. In February of 2023, the underwater Cubic Kilometer Neutrino Telescope (KM3NeT) detected a high-energy neutrino with 30 times more energy than any previously detected neutrino. Amazingly, KM3NeT detected this particle while under construction, using only 20 percent of its photodetectors. Neutrinos lie at the frontier of scientific unknowns about the universe. However, there's a problem—neutrinos also like to keep to themselves. They're the ultimate recluses of the particle physics world, but scientists have developed tools over decades to detect the reactions they can sometimes set off. One of those detectors is known as the Cubic Kilometer Neutrino Telescope (KM3NeT), which comprises two detector arrays anchored to the floor of the Mediterranean Sea. The Astroparticle Research with Cosmics in the Abyss (ARCA) array is located off the coast of Sicily, and in the middle of the night on February 13, 2023, the installation recorded an unusual signal—a high-energy muon streaking through the array in just a few microseconds. From the data, scientists determined that the muon contained 120 peta-electron volts (PeV) of energy, and further extrapolated that the instigating neutrino must have contained energies of 220 peta-electron volts—a level that's 30 times higher than any neutrino ever detected. The results of this astounding discovery were published in the journal Nature. 'Neutrinos are the closest thing to nothing that we can imagine,' Paschal Coyle, Centre national de la recherche scientifique (CNRS) researcher and KM3NeT spokesperson at the time of the detection, said during a press conference earlier this week, 'but they are key to fully understanding the workings of the universe.' Scientists don't directly detect neutrinos, but they can infer things about them by analyzing their interactions with the weak nuclear force (neutrinos also interact with gravity, but the effects are negligible). To give you a sense of how difficult it can be to detect a neutrino, scientists estimate that if 10 trillion neutrinos generated from the Sun pass through the Earth, only one will interact with a particle and produce a detectable reaction. Put another way, you could construct a lead wall five light years in width, and 50 percent of neutrinos could still pass through unscathed. So, not only did it come as a surprise when the ARCA array lit up in February of 2023, it was almost unbelievable that the experiment—which, at that time, had only deployed 10 percent of its photoreceptors—detected something as extraordinary as KM3-230213A (the name of the neutrino event). Two things make this particular muon (and, by extension, the neutrino that created it‚, particularly interesting. The first is its high energy level, which suggests a cosmic origin. The second is the angle of its trajectory. Because it was close to the horizon, it's likely that the neutrino collided with an atom in the deep sea surrounding the detector. 'Neutrinos are one of the most mysterious of elementary particles. They have no electric charge, almost no mass and interact only weakly with matter,' Rosa Coniglione from KM3NeT said in a press statement. 'They are special cosmic messengers, bringing us unique information on the mechanisms involved in the most energetic phenomena and allowing us to explore the farthest reaches of the universe.' Although the researchers can't be sure of the neutrino's origin, it's likely that the particle originated from a cataclysmic event like a gamma-ray burst, accreting supermassive black hole, or supernova explosion. It's also possible that energetic cosmic rays that ferried this neutrino to us interacted with protons found in the cosmic microwave background radiation, creating what's known as a 'cosmogenic neutrino.' KM3NeT is only at the beginning of its journey—this discovery popped up when the device was using only 21 of its planned 230 detection lines. And scientists are hopeful that this high-energy particle will be only the first of many similar discoveries. The project will also get a major assist in the exploration of neutrinos from the Deep Underground Neutrino Experiment, or DUNE, when it goes online in the coming years. Neutrinos may be the universe's most reclusive particles, but scientists are trying their best to bring some of their anti-social behaviors to light. You Might Also Like The Do's and Don'ts of Using Painter's Tape The Best Portable BBQ Grills for Cooking Anywhere Can a Smart Watch Prolong Your Life?
