Can the Large Hadron Collider Create a Black Hole? Assessing CERN’s LHC Safety

Overview

In this Ashram episode, host Alex McColgan examines the idea that CERNs Large Hadron Collider could create a black hole that might swallow the Earth. He walks through how black holes form, what energy scales are involved in particle collisions, and how Hawking radiation could cause microscopic black holes to evaporate long before they grow. The video also discusses the possibility of extra dimensions lowering the Planck energy, why even if micro black holes were created they would pose little risk, and how cosmic rays continually collide with Earth at energies well above collider energies without creating disaster. The aim is to separate myth from physics and explain why science is not on the brink of planetary destruction, even if some scenarios remain theoretically possible.

Introduction: The Fear and the Facts

The video opens by acknowledging a popular fear that a laboratory experiment could unleash a planet-destroying black hole. The host reframes the question as a physics problem about energy scales, spacetime, and the properties of black holes. The aim is to cut through sensational headlines and explain what is physically plausible given what we know about gravity, quantum effects, and high-energy collisions.

How the LHC Works

The Large Hadron Collider is described as a 27-kilometer ring of magnets that accelerates protons and heavy ions to nearly the speed of light. Collisions occur at specific points where detectors record the debris, enabling physicists to infer the creation of new particles and test the standard model. The talk highlights that the LHC achieves energies on the order of tens of TeV per collision, far below macroscopic energy scales yet sufficient to probe fundamental physics such as the Higgs boson and potential dark matter candidates.

Energy Scales and the Planck Threshold

A central theme is the comparison between collider energies and the Planck energy. The Planck scale represents a regime where classical physics breaks down and quantum gravity becomes essential. Scientists have shown that you would need energies far exceeding our current capabilities to form a black hole in a head-on proton collision. The discussion emphasizes that even optimistic extrapolations for future colliders would still be short of this threshold unless new physics drastically lowers it.

Extra Dimensions and Theoretical Safety Margins

The video considers speculative ideas from string theory that additional curled-up dimensions could reduce the effective Planck scale. If such dimensions exist, they could in principle alter the conditions needed to create black holes. However, even in these scenarios, the consensus is that any produced black holes would be microscopic and would evaporate quickly, posing no threat to the planet.

Hawking Radiation and Micro Black Holes

Hawking radiation is described as a quantum effect that causes black holes to emit particles and lose mass over time. For tiny black holes, evaporation would happen extremely rapidly, effectively preventing any dangerous growth. The presenter notes that direct observation of Hawking radiation from astrophysical black holes remains elusive, but analogous experimental evidence from sonic black holes and theoretical frameworks support the evaporation idea at small scales.

Why a Black Hole from the LHC Is Unlikely to Harm Earth

The argument proceeds with practical risk assessment: a black hole formed in a collider would have minuscule mass, would evaporate in a fraction of a second, and would not interact with matter in a way that could cause planetary destruction. The video also points out that cosmic rays collide with Earth naturally at higher energies than the LHC, yet no such catastrophic outcome has occurred, reinforcing the safety conclusion.

Conclusion: Safety, Skepticism, and Scientific Guardrails

The host concludes that while physics can entertain highly theoretical possibilities, the actual risk from the LHC is vanishingly small. Historical caution in high-energy experiments is acknowledged, but the current body of evidence supports continued scientific exploration with appropriate safeguards. The video ends with a light reminder to consider broader questions about the universe, while reassuring viewers that CERNs work, in practice, is not a planetary threat.