Black Holes Could Replace $30 Billion Particle Colliders

Scientists have discovered that supermassive black holes naturally create the same high-energy particle collisions that researchers spend decades and billions of dollars building on Earth.

Johns Hopkins researchers show that rapidly spinning black holes at galaxy centers could serve as cosmic supercolliders, potentially reaching energies matching or exceeding the most powerful human-made accelerators while offering a cheaper alternative to next-generation facilities that could cost $30 billion and take 40 years to construct.

Nature’s Free Particle Accelerator

The discovery, published in Physical Review Letters, reveals how black holes spinning near their maximum possible speed can accelerate particles to extraordinary energies. When material falls into these cosmic giants, some particles get caught in chaotic collisions near the black hole’s edge, reaching speeds that rival or surpass what scientists achieve in facilities like Europe’s Large Hadron Collider.

“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,” said study co-author Joseph Silk, an astrophysics professor at Johns Hopkins University and the University of Oxford, UK. “That’s why there are discussions underway to build a much more powerful version, a next-generation supercollider. 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.”

The Retrograde Advantage

The key lies in what happens when material approaches a spinning black hole in the opposite direction of its rotation—called retrograde motion. Unlike material flowing in the same direction as the black hole’s spin, retrograde material must travel much farther before reaching the point of no return, giving it more time to accelerate to extreme speeds.

During this extended “run-up” toward the black hole, particles can reach energies in the tens to hundreds of teraelectronvolts—the same range targeted by proposed next-generation colliders. The process creates what scientists call the Bañados-Silk-West effect, where particles achieve seemingly impossible energies through gravitational acceleration.

A Natural Cosmic Setup

What makes this discovery particularly exciting is how naturally it occurs in space. Many supermassive black holes alternate between active and quiet periods as they consume material. When a previously spinning black hole “wakes up” to feed again—perhaps after a star gets torn apart nearby—the new material has an equal chance of approaching from any direction.

The researchers calculated that moderate feeding rates could produce particle fluxes of roughly 10^44 particles per second for typical black hole masses, creating countless opportunities for high-energy collisions.

Detecting Cosmic Collisions

So how would scientists detect these natural particle accelerators? The answer lies in existing observatories already watching the sky for cosmic events.

“If supermassive black holes can generate these particles by high-energy proton collisions, then we might get a signal on Earth, some really high-energy particle passing rapidly through our detectors,” said Silk, who is also a researcher at the Institute of Astrophysics in Paris and at the University of Oxford. “That would be the evidence for a novel particle collider within the most mysterious objects in the universe, attaining energies that would be unattainable in any terrestrial accelerator.”

Facilities like the IceCube Neutrino Observatory at the South Pole and the Kilometer Cube Neutrino Telescope in the Mediterranean could potentially spot these cosmic collision products. In fact, a recent ultra-high-energy neutrino detected by KM3Net at 220 petaelectronvolts—hundreds of times more energetic than typical detections—might represent exactly this kind of black hole supercollider signature.

Beyond the Event Horizon

The research reveals fascinating physics about what happens near black holes. As particles spiral inward, some collide and fall past the point of no return, disappearing forever. But others gain so much energy and momentum that they escape, potentially carrying signatures of exotic physics across the universe.

“Some particles from these collisions go down the throat of the black hole and disappear forever. 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,” Silk said.

A Complement, Not a Replacement

The scientists emphasize that black hole supercolliders wouldn’t replace human-made facilities entirely, but could provide crucial complementary data. While terrestrial accelerators offer precise control over experimental conditions, cosmic accelerators might reveal phenomena impossible to recreate on Earth.

“We figured out how energetic these beams of particles could be: as powerful as you get from a supercollider, or more. It’s very hard to say what the limit is, but they certainly are up to the energy of the newest supercollider that we plan to build, so they could definitely give us complementary results,” Silk said.

The main limitation? Distance. “The difference between a supercollider and a black hole is that black holes are far away,” Silk said. “But nevertheless, these particles will get to us.”

As federal funding cuts threaten decades of particle physics research, this cosmic alternative could help scientists continue probing the universe’s deepest mysteries—including the elusive dark matter that makes up most of the cosmos but has never been directly detected.