Something Terrifying Could Happen Inside CERN

Added: 2026-05-12

[00:00:00]On the 21st of March 2008, a man named Walter Wagner walked into the United States District Court for the District of Hawaii and filed a lawsuit. His co-plaintiff was Luis Sancho. Their demand was extraordinary. They wanted a federal judge to stop the largest scientific experiment ever built from turning on. The defendants were not a small list. European Council for Nuclear Research, the United States Department of Energy, the National Science Foundation, Furma Lab, four of the most serious research institutions in the world, named in a civil suit in a Honolulu courthouse accused of preparing to end everything. Wagner and Sancho believed that the large hadron collider, then weeks away from its first attempts at high energy collisions, might create a black hole. not a small one, not a harmless one, a black hole that would sink into the Earth, begin devouring matter, and eventually consume the planet. They also feared a second kind of object called a strangelet, a hypothetical form of matter that could, in the worst imagined scenarios, convert ordinary matter into more of itself.

[00:01:06]Months later, the journalist John Oliver sat across from Vagnner on the Daily Show and asked him what he thought the odds of the LHC destroying the Earth actually were. Wagner answered that the odds were 50/50. It would either happen or it would not.

[00:01:21]>> It's a chance. It's a 50-50 chance.

[00:01:23]>> You coming back to this 50/50 thing.

[00:01:25]It's weird, Walter.

[00:01:27]>> Well, if you have something that can happen and something that uh won't necessarily happen. It's going to either happen or it's going to not happen. And so that's the best guess is in one. The lawsuit was dismissed, but the question underneath it was not the work of a crank. Serious physicists had written peer-reviewed papers exploring exactly this possibility. The question was taken seriously enough that CERN commissioned an independent safety report signed by some of the most respected names in physics to answer it. To understand why, you have to understand what the machine actually is. Beneath the border between Switzerland and France, roughly 100 m down, there is a tunnel. It forms a ring 27 km across. Inside that ring, two beams of protons travel in opposite directions, guided by superconducting magnets cooled to temperatures colder than deep space. Approximately 1.9 Kelvin or roughly -271° C. The LHC is in this narrow sense one of the coldest large scale environments.

[00:02:35]In run three, the operating phase that began in 2022, each proton is accelerated to an energy of 6.8 terra electron volts TV. When two of these protons collide headon, the total energy released at the collision point reaches 13.6 TV. The speed of these protons is easier to state than to picture. They move at roughly 0.999991 times the speed of light. In absolute terms, they are about 3 m/s slower than a photon. In the time it takes you to blink, each proton has gone around the ring roughly 3,000 times. CERN itself offers the cleanest analogy for the energy involved. A single proton in the LHC carries about the energy of a safety pin falling from the height of 2 cm.

[00:03:22]That sounds absurdly small, and it is until you remember that the energy is concentrated into a space smaller than an atomic nucleus. As in all of particle physics, density is the whole story.

[00:03:34]Four great detectors watch what happens at the collision points. Atlas and CMS are the giants, general purpose, each the size of a cathedral. Alice studies the primordial soup of quarks and gluons that existed in the first micros secondsond after the big bang. LHCB hunts for asymmetries between matter and antimatter. So, the real question, the one hiding behind the courtroom drama in Hawaii, is this. Could the LHC actually do what the lawsuit feared? To answer it, you have to look at something far stranger than any collider. You have to look at gravity and at why it behaves in a way that makes no sense.

[00:04:18]Here is something that should bother you more than it probably does. Gravity is pathetically weak. Pick up a small fridge magnet. Hold it above a paperclip resting on a table. The paperclip jumps.

[00:04:35]Think about what just happened. The entire gravitational pull of the planet beneath you. A ball of rock and iron 6,000 km deep was defeated by a sliver of magnetized metal you can fit in your palm. This is not a quirk. It is one of the deepest unsolved problems in physics. The force that holds galaxies together, that curves spaceime, that gives the universe its shape, is by a staggering margin the weakest of the four fundamental forces. It is not just a little weaker than the others. It is approximately 10 to the power of 36.

[00:05:09]This number is so large that if you tried to represent it by stacking grains of sand, the pile would dwarf the observable universe. And yet this disparity is a feature of every atom in your body, of every planet in every galaxy. It is not an edge case. It is the ground state of reality. Nobody knows why. Physicists have a name for this puzzle. They call it the hierarchy problem. The weak force, the force responsible for radioactive decay, works at an energy scale of about 100 giga electron volts, GV. The particles connected to this force like the W and Z bosens as well as the Higs bosen all have masses around the same scale. The Higs bosen discovered in 2012 at the Large Hadron Collider by Atlas Collaboration and CMS collaboration has a mass of about 125 gig electron volts.

[00:06:03]Here is the problem. According to quantum physics, the Higs mass should be much larger. Tiny quantum effects from virtual particles constantly interacting with the Higs should push its mass upward to enormous values, possibly all the way to the plank scale. But that is not what we see. The Higs is still relatively light at 125 gig electron volts. For this to happen, the huge quantum corrections and the true Higs mass would need to cancel each other out with extraordinary precision, about one part in 10 to the 34th power. Even the smallest mismatch would make the Higs incredibly heavy. Physicists find this suspicious. It feels unnatural that the universe would need such an unbelievably precise balancing act for the Higs to exist at its observed mass. Many believe this hints that some deeper still unknown physics is protecting the Higs mass from becoming huge. The mystery becomes even stranger when you compare the scales involved. The weak scale is around 100 g electron volts while the plank scale is about 10 to the power of 19 g electron volts. That is a difference of 17 orders of magnitude a gigantic gap. And so far experiments have found almost nothing in between these two scales. Physicists call this vast empty gap the desert. Gaps like this make physicists uncomfortable in a specific way. In physics, when you find a space that large, it usually means you are missing something. A particle, a symmetry, an entire layer of reality that should be there and is not. The plank scale matters for another reason and it matters directly for the question of whether anything we build can ever create a black hole. In ordinary physics, the plank scale is the wall.

[00:07:50]Creating a black hole requires compressing a certain amount of energy into a small enough region that spacetime folds in on itself and a horizon forms. In our familiar three dimensions, the energy required is set by the plank scale. Roughly a quadrillion times more than the LHC can reach. Not out of reach by a little, out of reach by an almost incomprehensible margin. So, in the standard picture, the lawsuit in Hawaii was answering itself.

[00:08:19]No machine on Earth now or in any foreseeable future could put enough energy in a small enough place. The end.

[00:08:27]Except that in 1998, three physicists wrote a paper that punched a hole straight through that reasoning. Their names were Nema Arcani Hamemed, Savast Demopoulos, and Gadvali. The paper appeared in physics letters B and its title was the hierarchy problem and new dimensions at a millimeter. What they proposed is still decades later one of the strangest and most beautiful ideas in modern theoretical physics. They asked a simple question. What if gravity is not actually weak? What if gravity only looks weak because we are not seeing all of it? In their model, often called the add model, the universe has more than three spatial dimensions.

[00:09:08]There are extra ones curled up so tightly and folded so compactly that they are invisible to any experiment we have ever done. The particles that make up you, the chair you are sitting on, the light reaching your eyes, all of this ordinary matter is confined to a three-dimensional surface they call a brain floating inside a larger space.

[00:09:27]The particles of the standard model cannot leave that surface. They are stuck to it. But gravity can leave.

[00:09:34]Gravity in this picture is the only force that can spread into the extra dimensions. And because it spreads, it gets thinned, diluted. Most of its strength is bleeding sideways into spaces we cannot see. Imagine a thin sheet floating in a tank of water. Drop dye onto the sheet and it spreads across the surface of the sheet, but can never leave it. For the dye, only the sheet exists. Nothing from the surrounding water can enter the sheet and nothing on the sheet can escape into the water. The sheet is completely impermeable to matter exchange in both directions. Now hit the tank. A wave moves through the entire water volume above, below, and through the sheet. The sheet feels only a fraction of the wave because most of its energy spreads through regions the sheet cannot access. If tiny creatures lived on the sheet, they would think the wave was strangely weak, never realizing most of its energy vanished into dimensions beyond their world.

[00:10:35]Physicists use this as an analogy for our universe. The sheet is our universe or brain. The dye is ordinary matter, atoms, light, electrons, and quarks trapped inside it. The surrounding water represents extra dimensions. The wave is gravity. Unlike matter, gravity may spread into these extra dimensions. If this picture is correct, gravity at very short distances is not weak at all. It is enormous, comparable to the other forces. The weakness we measure in our daily lives might be an illusion produced by geometry rather than a fundamental property of nature.

[00:11:21]In 2001, two physicists took the ADD idea and did something that changed the nature of the conversation. They sat down and calculated what it would actually mean. Their names were Sarvis Demopoulos, one of the original authors of the Extra Dimensions proposal, and Greg Lansburg. The paper they published in Physical Review Letters carried a title that should not have been possible to write with a straight face 3 years earlier. It was called Black Holes at the LHC. What they worked out in careful mathematical detail was the rate at which microscopic black holes would be produced inside the collider if the add framework turned out to be correct. Not as a thought experiment, as a prediction with numbers and probabilities testable the moment the machine turned on. The mechanism itself is easier to picture than it sounds. A proton is not a single point. It is a swarming bundle of smaller constituents, quarks and gluons, bound together by the strong force. When two protons meet headon at 13.6 TV, what actually collides are pairs of these inner constituents, the partn carrying some fraction of the proton's total energy. Most of the time, the partners graze past each other. Energy is exchanged, particles are born, and the aftermath scatters outward into the detectors. This is the bread and butter of particle physics. It is what the LHC does trillions of times a day. But once in a while in the ADD picture, something stranger could happen. Two patterns pass close enough. Close in a very specific sense. Close enough that the energy they carry packed into the tiny volume between them falls within a critical distance. That critical distance has a name, the Schwvartzild radius. It is the radius at which a given amount of mass or energy if squeezed inside it must form an event horizon. It is the line past which gravity becomes inescapable.

[00:13:21]Demopoulos and Lansberg argued that when two pardons cross that line, the result is not a complicated mess. The result is a black hole. The probability of forming one is approximated roughly by the area of a disc the size of that horizon. If you can throw enough energy into a small enough region, spacetime does what spacetime does. It collapses. Pause here and look at what is actually being described. An object, an event horizon, a singularity formed inside a machine on Earth produced from the collision of two particles that are not even the whole proton. The physical nature of this object is worth sitting with. It would carry a mass of several terra electron volts which in everyday units is almost nothing. Something in the neighborhood of 10 the minus 23rd g a trillionth of a trillionth of a g. It would be smaller than the proton that made it. Smaller than anything we normally call a particle. And this is the place where a certain instinct needs to be switched off. The word black hole pulls images from somewhere deep in the imagination.

[00:14:29]The black hole at the center of the galaxy, 4 million times the mass of the sun, the dark body at the core of Signis X1, the super massive monster in the first event horizon telescope image.

[00:14:41]None of that applies here. A stellar black hole is the final collapse of a star 20 or more times the mass of the sun. Its gravity is overwhelming because its mass is overwhelming. A micro black hole at the LHC would have the gravitational pull of a grain of dust less. It would not fall toward the Earth's center in any meaningful sense.

[00:15:02]It would not accrete matter in any meaningful sense. It would not grow. It would, if anything, be the most delicate object ever created. All of this rests on a single heavy condition. The add framework has to be correct. Extra dimensions have to exist and the true plank scale has to sit somewhere close to one terra electron volt. If those assumptions fail, the entire prediction fails with them. In the standard picture of physics, without extra dimensions, no collider humans could build in the next thousand years would come within a rumor of making a black hole. But if the assumptions hold, the LHC would not produce one black hole. It could produce many, a steady, measurable stream of them buried inside the ordinary noise of proton collisions waiting for someone to notice. Which raises the question that the 2008 lawsuit was actually asking, stripped of the hysteria, what happens to one of these objects the moment after it is born.

[00:16:08]The image we carry of a black hole is a mouth. something that swallows.

[00:16:12]Something that grows on whatever it touches. This is the picture the 2008 lawsuit was leaning on. A horizon opens.

[00:16:20]Matter falls in. The thing gets larger.

[00:16:23]Eventually, it gets large enough to sink through the crust and begin devouring the Earth from the inside. Steven Hawking killed this picture in 1974 by applying quantum field theory to curved spaceime. What he showed in a calculation that quietly rewrote the physics of black holes is that event horizons are not permanent. They leak.

[00:16:45]The quantum vacuum around a horizon is not empty and under the right conditions, the gravitational field of a black hole can separate pairs of virtual particles in a way that sends energy streaming outward. The black hole loses mass in the process slowly at first if the hole is large. But the rule cuts the other way than intuition suggests.

[00:17:05]Smaller black holes radiate more fiercely, not less. A black hole the size of a mountain would glow. A black hole the mass of a proton would not so much evaporate as detonate. A micro black hole produced at the LHC carrying a mass of several TV would sit at the extreme end of this. Its predicted lifetime is around 10 to the minus 27th of a second. To give that number any handhold at all, consider this. In that span of time, a beam of light travels less than the width of a single atomic nucleus. The black hole is gone before it can cross the space between its own constituent parts. It does not drift. It does not fall. It does not grow. It appears and then it is finished. If tiny black holes could form in high energy collisions, they would vanish almost instantly and produce a sudden burst of particles rather than leaving anything behind. You would see a firework of quarks, leptons, photons, and gluons all shooting out from a single point with unusually high energy. Physicists look for this kind of event in detectors.

[00:18:09]Many particles emerging at once, evenly spread in all directions, and carrying more energy than typical collisions.

[00:18:16]This is expected from Hawking radiation.

[00:18:18]It is not selective. It emits all types of particles according to simple statistical rules, similar to how a hot object glows. That democratic mix of particles is important because most known processes do not produce such a uniform high multiplicity burst. If seen, it would be a strong hint of something beyond the standard model.

[00:18:39]There is an honest caveat to place on all of this. Hawking radiation has never been directly detected. The LHC safety assessment group, the independent body commission to review the safety of the collider, said this openly in their 2008 report. Nobody has watched a black hole evaporate. Nobody has caught the radiation coming off one. The prediction stands on theoretical ground built from general relativity and quantum field theory. And almost every working physicist accepts it. But acceptance is not observation. And the report did not pretend otherwise. If the Hawking argument were the only thing standing between us and the scenario the lawsuit feared, there might still be room for the faintest doubt, it is not the only thing. The second argument is older than the LHC, older than the AD paper, older than Hawkings calculation. It is written in the sky. Every second of every day, the Earth is struck by particles from space. Protons and atomic nuclei are accelerated to energies that dwarf anything built by human hands. They come from supernova shock waves from the accretion discs of super massive black holes from sources we have not yet identified. They are called ultra high energy cosmic rays and the most extreme of them carry energies that make the LHC look like a toy. In October 1991, a detector in the Utah desert registered a single particle whose energy was so absurd the researchers gave it a nickname, the oh my god particle. Its energy was around 3 * 10 20th electron volts. in the units particle physicists use for the LHC. That is roughly 320 million TV. Tens of millions of times more energetic than any collision the Large Hadron Collider has ever produced or will ever produce. And that was one particle. Others like it, not quite as extreme, but still far above anything the LHC can reach, arrive constantly.

[00:20:42]They strike the upper atmosphere of this planet. They strike the surface of the moon, which has no atmosphere to shield it. They strike the sun. They strike neutron stars and white dwarfs, the densest compact objects known, whose matter is packed so tightly that a teaspoonful would weigh hundreds of millions of tons. If those collisions could create stable, dangerous black holes, they already would have. The moon would not be there. The sun would not be there. The dense stars in the sky would have collapsed long ago, one by one, as their own cosmic ray bombardments produced the doomsday objects the Hawaii lawsuit feared. Stefan Coutu, a physicist at Penn State, put it in about as plain a sentence as physics permits.

[00:21:25]If cosmic ray collisions could create black holes that would swallow the Earth, it would have happened already.

[00:21:31]The argument goes further still. In 2008, the physicists Steven Giddings and Michelangelo Mangano published an analysis that tried to close even the most paranoid remaining loophole. What if, they asked, a micro black hole somehow evaded Hawking radiation entirely? What if it was stable, neutral, and persistent? What would it do? Their calculations showed that even in that worst case, the time required for such an object to accrete enough matter to pose any threat to the earth exceeded the age of the universe. And more damning still, dense stars like white dwarfs bombarded by cosmic rays for billions of years would have already destroyed themselves if the scenario had any truth to it. They have not. They are still shining. The lawsuit in Hawaii was not dismissed because the science was hidden or because the judge trusted CERN over two worried men. It was dismissed because the universe had already run the experiment the plaintiffs feared. It had run it on every star, every moon, every rock in the solar system, every night for 4 billion years. The answer kept coming back the same. Nothing happened.

[00:22:46]In 2010, only months after the first collisions, the CMS collaboration ran the first dedicated search for a microscopic black hole in human history.

[00:22:55]They had 35 inverse peekabonds of data at 7TV. A small hall by modern standards, but enough to ask the question. Their signature was specific.

[00:23:04]A black hole would decay into many particles at once, carrying a total transverse energy far above anything a normal collision produced, radiating outward from a single point in a pattern too busy and too symmetrical to come from ordinary quark scattering. CMS filtered their collisions for that shape. They found the background. Every event was explained by the standard model. The result was written up as the first direct experimental limit on black hole production ever set. microscopic black holes excluded for masses between three and a half and 4 and a half TV across a range of ADD parameters. The searches continued through run two at 13TV from 2015 to 2018. Run 3 began in 2022 and is still in progress, operating at 13.6TV.

[00:23:54]Atlas alone collected roughly 165 inverse femtobonds of proton proton data in the first three years of run three more than the entire run two total. The signature physicists look for has not appeared in any of it. A theory that predicted a specific striking event and an experiment that looked carefully and saw none is not a draw. It is the universe telling you something. Every year the LHC runs without producing a black hole. The window of possibility for the ADD framework gets smaller. The fundamental scale of gravity, if extra dimensions exist, has been pushed past the reach of the current machine. Newer work is closing the door from a different direction. In 2023, a group led by Matthew Lake published a paper in Frontiers in Astronomy and Space Sciences, arguing that even if extra dimensions are real, the rules of quantum uncertainty in higher dimensional spaceime may prevent micro black holes from forming at LHC energies at all. The door that the original add theory opened may never have been a door. Physicists have already moved on to what the next generation of machines could reveal. A 2024 analysis by Halil Gams and colleagues estimated that a future 100TV collider, the proposed future circular collider, could probe fundamental gravity scales up to 45 TV.

[00:25:21]Nothing close to that exists yet. The LHC itself will be upgraded to a high luminosity version around 2030, designed to collect 10 times more data at roughly the same energy. More collisions? Same question. The hierarchy problem remains.

[00:25:38]Gravity is still absurdly weak. Whatever hides the answer, it is not sitting where the neat, elegant version of the theory puts it. The Hawaii lawsuit was afraid of the wrong thing. The Large Hadron Collider was never going to swallow the Earth. The cosmic ray sky and Hawkings calculation had already settled that before the first beam circulated. Underneath the fear, though, was a serious question. One physics has not finished asking whether the universe is stranger than it looks. Whether the three dimensions we can see and the four forces we can measure are all there is.

[00:26:13]The add framework was one specific falsifiable answer. Gravity seems weak because it leaks somewhere else and a powerful enough machine could catch a piece of the leak. Physicists built the machine. The leak has not shown up. That absence is its own result. The simplest version of the hidden dimensions idea is now under serious challenge and whatever ultimately replaces it will likely be more complex than what Arcani Hammed, Demopoulos, and Dvali proposed in 1998.

[00:26:42]This is how physics is supposed to work.

[00:26:44]The AD theory didn't just propose extra dimensions. It made clear predictions.

[00:26:50]At certain energies, particle collisions should produce signs like tiny black holes and distinctive bursts of particles. It also told experiments exactly where and how to look.

[00:27:00]Physicists searched carefully using large colliders and found nothing. That isn't failure, it's progress. When a theory is tested and ruled out, science becomes more precise. The range of possible explanations shrinks. So now we know more clearly where the answer is not. Whatever the correct theory is, it must lie beyond the region already tested. Gravity is still pathetically weak. A paperclip still jumps to a fridge magnet against the pull of an entire planet. The 17 order of magnitude gap in the forces is still there, still silent, still waiting. The extra dimensions could exist at scales smaller than anything we can currently reach.

[00:27:40]They could be absent entirely. The hierarchy problem could turn out not to be a problem at all, but a clue pointing somewhere nobody has thought to look.

[00:27:49]The most honest sentence in modern physics remains what it has always been.

[00:27:54]We do not know yet. Beneath the border between France and Switzerland, the collider is still running. The 2025 Proton run finished in early December with record performance. The high luminosity upgrade begins at the end of this decade. A much larger machine, the Future Circular Collider, sits on the drawing board. Each one will ask a sharper version of the same question that the 2008 lawsuit was stumbling toward. Somewhere in the data these machines will eventually produce, or in theories nobody has written yet, the next piece of the answer is hiding.