Latest news with #RogerPenrose
Yahoo
19 hours ago
- Science
- Yahoo
What if the Big Bang wasn't the beginning? New research suggests it may have taken place inside a black hole
When you buy through links on our articles, Future and its syndication partners may earn a commission. The Big Bang is often described as the explosive birth of the universe — a singular moment when space, time and matter sprang into existence. But what if this was not the beginning at all? What if our universe emerged from something else — something more familiar and radical at the same time? In a new paper, published in Physical Review D, my colleagues and I propose a striking alternative. Our calculations suggest the Big Bang was not the start of everything, but rather the outcome of a gravitational crunch or collapse that formed a very massive black hole — followed by a bounce inside it. This idea, which we call the black hole universe, offers a radically different view of cosmic origins, yet it is grounded entirely in known physics and observations. Today's standard cosmological model, based on the Big Bang and cosmic inflation (the idea that the early universe rapidly blew up in size), has been remarkably successful in explaining the structure and evolution of the universe. But it comes at a price: it leaves some of the most fundamental questions unanswered. For one, the Big Bang model begins with a singularity — a point of infinite density where the laws of physics break down. This is not just a technical glitch; it's a deep theoretical problem that suggests we don't really understand the beginning at all. To explain the universe's large-scale structure, physicists introduced a brief phase of rapid expansion into the early universe called cosmic inflation, powered by an unknown field with strange properties. Later, to explain the accelerating expansion observed today, they added another "mysterious" component: dark energy. Related: 5 fascinating facts about the Big Bang, the theory that defines the history of the universe In short, the standard model of cosmology works well — but only by introducing new ingredients we have never observed directly. Meanwhile, the most basic questions remain open: where did everything come from? Why did it begin this way? And why is the universe so flat, smooth, and large? Our new model tackles these questions from a different angle — by looking inward instead of outward. Instead of starting with an expanding universe and trying to trace back how it began, we consider what happens when an overly dense collection of matter collapses under gravity. This is a familiar process: stars collapse into black holes, which are among the most well-understood objects in physics. But what happens inside a black hole, beyond the event horizon from which nothing can escape, remains a mystery. In 1965, the British physicist Roger Penrose proved that under very general conditions, gravitational collapse must lead to a singularity. This result, extended by the late British physicist Stephen Hawking and others, underpins the idea that singularities — like the one at the Big Bang — are unavoidable. The idea helped win Penrose a share of the 2020 Nobel prize in physics and inspired Hawking's global bestseller A Brief History of Time: From the Big Bang to Black Holes. But there's a caveat. These "singularity theorems" rely on "classical physics" which describes ordinary macroscopic objects. If we include the effects of quantum mechanics, which rules the tiny microcosmos of atoms and particles, as we must at extreme densities, the story may change. In our new paper, we show that gravitational collapse does not have to end in a singularity. We find an exact analytical solution — a mathematical result with no approximations. Our maths show that as we approach the potential singularity, the size of the universe changes as a (hyperbolic) function of cosmic time. This simple mathematical solution describes how a collapsing cloud of matter can reach a high-density state and then bounce, rebounding outward into a new expanding phase. But how come Penrose's theorems forbid out such outcomes? It's all down to a rule called the quantum exclusion principle, which states that no two identical particles known as fermions can occupy the same quantum state (such as angular momentum, or "spin"). And we show that this rule prevents the particles in the collapsing matter from being squeezed indefinitely. As a result, the collapse halts and reverses. The bounce is not only possible — it's inevitable under the right conditions. Crucially, this bounce occurs entirely within the framework of general relativity, which applies on large scales such as stars and galaxies, combined with the basic principles of quantum mechanics — no exotic fields, extra dimensions or speculative physics required. What emerges on the other side of the bounce is a universe remarkably like our own. Even more surprisingly, the rebound naturally produces the two separate phases of accelerated expansion — inflation and dark energy — driven not by a hypothetical fields but by the physics of the bounce itself. One of the strengths of this model is that it makes testable predictions. It predicts a small but non-zero amount of positive spatial curvature — meaning the universe is not exactly flat, but slightly curved, like the surface of the Earth. This is simply a relic of the initial small over-density that triggered the collapse. If future observations, such as the ongoing Euclid mission, confirm a small positive curvature, it would be a strong hint that our universe did indeed emerge from such a bounce. It also makes predictions about the current universe's rate of expansion, something that has already been verified. This model does more than fix technical problems with standard cosmology. It could also shed new light on other deep mysteries in our understanding of the early universe — such as the origin of supermassive black holes, the nature of dark matter, or the hierarchical formation and evolution of galaxies. These questions will be explored by future space missions such as Arrakihs, which will study diffuse features such as stellar halos (a spherical structure of stars and globular clusters surrounding galaxies) and satellite galaxies (smaller galaxies that orbit larger ones) that are difficult to detect with traditional telescopes from Earth and will help us understand dark matter and galaxy evolution. These phenomena might also be linked to relic compact objects — such as black holes — that formed during the collapsing phase and survived the bounce. RELATED STORIES —When will the universe die? —Universe may revolve once every 500 billion years — and that could solve a problem that threatened to break cosmology —Scientists may have finally found where the 'missing half' of the universe's matter is hiding The black hole universe also offers a new perspective on our place in the cosmos. In this framework, our entire observable universe lies inside the interior of a black hole formed in some larger "parent" universe. We are not special, no more than Earth was in the geocentric worldview that led Galileo (the astronomer who suggested the Earth revolves around the Sun in the 16th and 17th centuries) to be placed under house arrest. We are not witnessing the birth of everything from nothing, but rather the continuation of a cosmic cycle — one shaped by gravity, quantum mechanics, and the deep interconnections between them. This edited article is republished from The Conversation under a Creative Commons license. Read the original article.
Yahoo
a day ago
- General
- Yahoo
New research challenges everything we know about the Big Bang
The Big Bang is often described as the explosive birth of the universe – a singular moment when space, time and matter sprang into existence. But what if this was not the beginning at all? What if our universe emerged from something else – something more familiar and radical at the same time? In a new paper, published in Physical Review D, my colleagues and I propose a striking alternative. Our calculations suggest the Big Bang was not the start of everything, but rather the outcome of a gravitational crunch or collapse that formed a very massive black hole – followed by a bounce inside it. This idea, which we call the black hole universe, offers a radically different view of cosmic origins, yet it is grounded entirely in known physics and observations. Today's standard cosmological model, based on the Big Bang and cosmic inflation (the idea that the early universe rapidly blew up in size), has been remarkably successful in explaining the structure and evolution of the universe. But it comes at a price: it leaves some of the most fundamental questions unanswered. For one, the Big Bang model begins with a singularity – a point of infinite density where the laws of physics break down. This is not just a technical glitch; it's a deep theoretical problem that suggests we don't really understand the beginning at all. To explain the universe's large-scale structure, physicists introduced a brief phase of rapid expansion into the early universe called cosmic inflation, powered by an unknown field with strange properties. Later, to explain the accelerating expansion observed today, they added another 'mysterious' component: dark energy. In short, the standard model of cosmology works well – but only by introducing new ingredients we have never observed directly. Meanwhile, the most basic questions remain open: where did everything come from? Why did it begin this way? And why is the universe so flat, smooth, and large? Our new model tackles these questions from a different angle – by looking inward instead of outward. Instead of starting with an expanding universe and trying to trace back how it began, we consider what happens when an overly dense collection of matter collapses under gravity. This is a familiar process: stars collapse into black holes, which are among the most well-understood objects in physics. But what happens inside a black hole, beyond the event horizon from which nothing can escape, remains a mystery. In 1965, the British physicist Roger Penrose proved that under very general conditions, gravitational collapse must lead to a singularity. This result, extended by the late British physicist Stephen Hawking and others, underpins the idea that singularities – like the one at the Big Bang – are unavoidable. The idea helped win Penrose a share of the 2020 Nobel prize in physics and inspired Hawking's global bestseller A Brief History of Time: From the Big Bang to Black Holes. But there's a caveat. These 'singularity theorems' rely on 'classical physics' which describes ordinary macroscopic objects. If we include the effects of quantum mechanics, which rules the tiny microcosmos of atoms and particles, as we must at extreme densities, the story may change. In our new paper, we show that gravitational collapse does not have to end in a singularity. We find an exact analytical solution – a mathematical result with no approximations. Our maths show that as we approach the potential singularity, the size of the universe changes as a (hyperbolic) function of cosmic time. This simple mathematical solution describes how a collapsing cloud of matter can reach a high-density state and then bounce, rebounding outward into a new expanding phase. But how come Penrose's theorems forbid out such outcomes? It's all down to a rule called the quantum exclusion principle, which states that no two identical particles known as fermions can occupy the same quantum state (such as angular momentum, or 'spin'). And we show that this rule prevents the particles in the collapsing matter from being squeezed indefinitely. As a result, the collapse halts and reverses. The bounce is not only possible – it's inevitable under the right conditions. Crucially, this bounce occurs entirely within the framework of general relativity, which applies on large scales such as stars and galaxies, combined with the basic principles of quantum mechanics – no exotic fields, extra dimensions or speculative physics required. What emerges on the other side of the bounce is a universe remarkably like our own. Even more surprisingly, the rebound naturally produces the two separate phases of accelerated expansion – inflation and dark energy – driven not by a hypothetical fields but by the physics of the bounce itself. One of the strengths of this model is that it makes testable predictions. It predicts a small but non-zero amount of positive spatial curvature – meaning the universe is not exactly flat, but slightly curved, like the surface of the Earth. This is simply a relic of the initial small over-density that triggered the collapse. If future observations, such as the ongoing Euclid mission, confirm a small positive curvature, it would be a strong hint that our universe did indeed emerge from such a bounce. It also makes predictions about the current universe's rate of expansion, something that has already been verified. This model does more than fix technical problems with standard cosmology. It could also shed new light on other deep mysteries in our understanding of the early universe – such as the origin of supermassive black holes, the nature of dark matter, or the hierarchical formation and evolution of galaxies. These questions will be explored by future space missions such as Arrakhis, which will study diffuse features such as stellar halos (a spherical structure of stars and globular clusters surrounding galaxies) and satellite galaxies (smaller galaxies that orbit larger ones) that are difficult to detect with traditional telescopes from Earth and will help us understand dark matter and galaxy evolution. These phenomena might also be linked to relic compact objects – such as black holes – that formed during the collapsing phase and survived the bounce. The black hole universe also offers a new perspective on our place in the cosmos. In this framework, our entire observable universe lies inside the interior of a black hole formed in some larger 'parent' universe. We are not special, no more than Earth was in the geocentric worldview that led Galileo (the astronomer who suggested the Earth revolves around the Sun in the 16th and 17th centuries) to be placed under house arrest. We are not witnessing the birth of everything from nothing, but rather the continuation of a cosmic cycle – one shaped by gravity, quantum mechanics, and the deep interconnections between them. Enrique Gaztanaga is a Professor in the Institute of Cosmology and Gravitation (University of Portsmouth) at the University of Portsmouth. This article is republished from The Conversation under a Creative Commons license. Read the original article.
Mint
29-05-2025
- Science
- Mint
Will AI ever grasp quantum mechanics? Don't bet on it
Artificial intelligence (AI) is moving fast—faster than many of us ever imagined. It can diagnose diseases from images, write complex computer programs, predict market trends and help simulate the birth of galaxies in just a few seconds. It would not be a joke to say one day it will find the final secrets of the universe—perhaps even of quantum mechanics (QM), that most puzzling theory in modern physics. As a physicist, I've used AI tools myself and been impressed by what they can do in seconds—things that used to take us years and huge amounts of funding. But I have a big doubt: AI may never truly 'understand' quantum mechanics. One might think that cracking the most mysterious theory in modern physics should not be difficult for AI, which is already helping scientists solve complicated equations and design quantum computers. But I am not so sure. And it's not about the power or programming. It's about something AI doesn't have: consciousness. Also Read: Dodgy aides: What can we do about AI models that defy humans? Let me take you back to my student days. I was sitting in a quantum physics lecture, listening to my professor talk about the famous double-slit experiment. It showed something interesting: tiny particles like electrons behave like waves—until we try to observe them. The moment we 'watch,' their behaviour changes. This strange result led to a shocking idea: the act of observing something can change reality itself. This is just like a person at a gathering who behaves freely when unobserved but changes behaviour once noticed. Similarly, electrons act like waves when not observed but change to particle-like behaviour upon measurement. Kurt Gödel's incompleteness theorems, proven in the 1930s, drew attention to the question of whether a formal system (like those AI is built on) could grab all mathematical truths. There will always be true statements that such systems cannot prove. This limitation applies to AI, which basically operates within algorithmic bounds. The British physicist and mathematician Roger Penrose—winner of a Nobel Prize in Physics and co-architect of modern general relativity—went where few dared. He extended Gödel's incompleteness theorems into the mind itself. In The Emperor's New Mind and Shadows of the Mind, Penrose argued that no algorithm, no matter how sophisticated, can truly mimic human consciousness. Why? Because consciousness, he suggested, doesn't arise from classical computation, but from quantum processes inside the brain. Also Read: Biases aren't useless: Let's cut AI some slack on these I tend to agree. AI can mimic quantum behaviour, but does not experience it. It calculates probabilities but never truly observes. It outputs solutions without thinking of their philosophical connections. It is like a brilliant student solving the Navier–Stokes equations (famously tied to a million-dollar prize), but without sensing the turbulence of the waves they describe. Modern AI, especially models that use machine learning and neural networks, is based on pattern recognition. They take large data-sets and find patterns, gathering and optimizing statistical regularities. This works well for visual recognition, language generation and even solving some physics problems, like calculating energy levels in molecular systems. However, QM goes beyond problem-solving. It is a philosophical dare. It asks questions that go beyond 'what happens' to 'why does this happen this way' and 'what does it mean for something to happen at all?' The debates between Einstein, Bohr and Schrödinger weren't about the output of calculations; they were about the nature of reality. Also Read: Confidently wrong: Why AI is so exasperatingly human-like Simulation isn't comprehension: There is a nice but critical difference between mimicking a phenomenon and understanding it. AI can simulate quantum systems with precision, especially with hybrid quantum-classical algorithms. Take the Schrödinger's Cat thought experiment. A large language model can cite 'Copenhagen interpretations,' but it does not wrestle with the paradox of a cat that's neither dead nor alive the way a physicist does. AI doesn't lose sleep over it. It doesn't look for an explanation that 'feels' right in its deepest sense. Its answers are not born of factual curiosity, but of statistical association. Understanding requires not just prediction, but a jump of abstraction and an act of belief—something deeply human. QM inherently resists usual logic. It is probabilistic, contextual and often counter-intuitive. AI, by contrast, is built atop layers of statistical models and optimization processes. Ironically, this might make AI more naturally aligned with the probabilistic nature of quantum physics than classical human thinking. Will AI ever generate such a revolutionary conceptual leap? Can it doubt the axioms it is trained on? It's not just math; it is a window to the basic nature of existence. Whether it reveals a multiverse or a single uncleared reality, it poses questions that touch on consciousness, causality and the limits of knowledge itself. AI is a powerful tool—perhaps the most powerful we've built. But as a physicist, I remain cautious. Until AI can construct questions it was not trained to ask, challenge patterns it was built upon and develop a sense of awe about its place in the universe, it will remain an assistant, not an originator of quantum understanding. At the end, it's not just about numbers, but about tackling the mysteries of the universe with curiosity, humility and imagination. And that, for now, remains uniquely human. These are the author's personal views. The author is a theoretical physicist at the University of North Carolina at Chapel Hill, US. He posts on X @NishantSahdev
Time of India
07-05-2025
- Science
- Time of India
What is the ‘Black Hole Bomb' theory and how scientists brought it to life in the lab
Source: Live Science Fascinating science behind the 'Black Hole Bomb' theory Black Hole rotation and its effect on space-time Real-world evidence of the 'Black Hole Bomb' Implications for Black Hole research Also Read | Spin in a black hole produces an effect called "frame dragging," an effect where space-time is curved around the spinning black hole by the rotation of the black hole. This profoundly affects particles that are close, transferring energy to particles that move in the direction of the rotation of the black hole. A breakthrough by scientists at the University of Southampton has moved the " Black Hole Bomb " theory of theoretical physics from theory into the laboratory, and a major advance has been made in the science of black holes and their unique "Black Hole Bomb" theory was originally discussed in the 1970s by brilliant scientists Roger Penrose and Yakov Zeldovich. Their theory was founded on the assumption that the rotational energy of a black hole could be tapped and magnified. In their hypothesis, they proposed that the spin of a black hole could be used as a method of increasing the energy levels in the surrounding environment. If this process repeated, it would be able to emit so much energy that it would have a strong possibility of producing a calamitous explosion, the same type of explosion which is produced by a the name is horrifying, the theory of the Black Hole Bomb is more of a fascinating scientific proposition than a threat. It shows how incredible potential there is with black holes as well as their sophisticated dynamics better a black hole is rotating, it warps the surrounding space-time—a phenomenon referred to as "frame dragging." Through this phenomenon, space-time gets curled up along the axis of rotation of the black hole and pulls other nearby particles along with it. In the case of particles moving along the direction of rotation of the black hole, this action can add more energy. One of the analogies used to describe this is the experience of traveling on a conveyor belt or airport moving walkway, in which a fragment of object passing along in the same direction as the walkway have been fascinated by this bizarre black hole phenomenon for decades because it is a reflection of the humongous and enigmatic power of these cosmic years, the Black Hole Bomb was merely a theoretical entity, trapped in papers and never put to the test or proved through experiment. Everything changed in an experiment led by Marion Cromb and her team at the University of Southampton. In their lab, the team employed a rotating aluminum cylinder confined by rotating magnetic fields surrounding it. By altering the rate of rotation of the magnetic fields relative to the cylinder, they were able to observe changes taking place in the energy dynamics of the test result was sensational. When the spinning cylinder spun faster than the external magnetic field, the energy of the system increased. When the magnetic field spun faster than the cylinder, energy levels plummeted. This experiment was capable of simulating conditions that are predicted to exist around a black hole's event horizon, demonstrating the Black Hole Bomb theory in the team released their results on the scientific preprint server, arXiv, making available to the wider scientific community a useful new piece of evidence for this discovery is a major breakthrough in black hole research. This makes it possible for researchers to explore the hypothetical energy of a black hole without having to observe or touch it, which under usual circumstances would be extremely difficult given the violent conditions within the area surrounding such cosmic monsters. By performing such experiments on rotating cylinders and magnetic fields, scientists can mimic and investigate phenomena in the ergosphere of a black hole, the area just outside its event this finding itself does not imply that black holes would or could be used as weapons or used in day-to-day technology, it provides a new understanding of one of the universe's most mysterious and potent forces. The findings pave the way for further research into the workings of black holes and potentially new advances in the years ahead.
Yahoo
06-05-2025
- Science
- Yahoo
Scientists Built a ‘Toy Model' of a Black Hole Bomb—and Brought a 50-Year-Old Theory to Life
An experimental setup mimics a 'black hole bomb' first theorized in 1971. The spinning cylinder with circuitry is true to the original idea, showing that it can be plausible. Electrical waves spin off in random ways until they compound and create a runaway effect. There's nothing some physicists love more than an outlandishly impossible sounding idea, from nuclear fusion power plants to Star Trek's warp drive. (Fusion people, don't come for us—we'll happily share when a plant makes net energy over its operating costs, whenever that may be.) And recently, in a study uploaded to the preprint server arXiv, a team of scientists claimed to have made a very simplified 'toy model' of something known as a black hole bomb. Could this particular decades-old idea be making a move toward real life? The answer is complicated. A black hole bomb is not a true black hole, obviously, but it is heavily inspired by the massive gravity wells. In 1971, Yakov Zeldovich iterated on Roger Penrose's groundbreaking observations about black holes and wondered if the conditions seen in these structures could be harnessed as energy. Unlike a space superstructure, a black hole bomb might be a graspable human size. But scientists like Stephen Hawking predicted that, under some conditions, this energy would be too small to measure and verify the theories. Zeldovich, therefore, suggested adding a resonator in the form of a cylindrical mirror surrounding the original cylinder. Like an insulated coffee cup, the added metallic layer would reflect energy back into the black hole, and that energy would accumulate until it exploded outward and shattered the mirror. Others have iterated on these designs ever since. In this recent study, the research team attempted to take that black hole bomb concept from idea to reality—or, at least, take the first step towards reality by creating a toy model. A toy model is a very boiled down version of a theorized system, as the name suggests. Today, toy models explore things like quantum information theory or nanomaterials—in other recently published research, scientists used one to help model the strength of mismatched shapes and study how a particular arrangement of quantum qubits performs in computing. To create their toy model, the scientists nested a conductive aluminum cylinder—solid and just four centimeters in diameter—inside three concentric layers of circuitry. The setup was then rotated by an attached direct current motor (not that different from what powers an electric drill or rotating cake plate). As the assembly spun, the waves it produced grew more and more unstable until they achieved a runaway chain reaction effect. As the spinning cylinder generated positive energy radiating outward, the black hole effect created in its center absorbed all the negative energy, and the positive energy increased even more as the cylinder continued to rotate. But, instead of resulting in the predicted explosion, the team designed their assembly to switch itself off once it reached a certain point, ensuring that it did not explode (a good call, because it sure seems like it could have otherwise). '[T]he physical ingredients are as proposed more than 50 years ago,' the scientists explained. 'The results show that extraction of rotational energy can be observed at low-frequencies, where the conditions for negative energies (or negative resistances) can be met. Furthermore, it also shows how this unstable regime can be switched on and off as predicted for the black hole bomb.' In other words, this setup realizes—almost exactly—what the 'golden age' black hole pioneers of the 1960s and 1970s were theorizing. The rest of the way toward a true black hole bomb, the team concluded, is a matter of when, not if. In the meantime, these results must be evaluated and recreated by others. You Might Also Like
