Lead and gold are different elements, with three protons’ difference between them (University of Seville)
Physicists attempting to recreate conditions from the earliest moments of the universe have unintentionally achieved what medieval alchemists only dreamed of: turning lead into gold.
The breakthrough occurred at the Large Hadron Collider in Switzerland during experiments designed to simulate the extreme environment shortly after the Big Bang. Researchers working on the ALICE experiment were smashing lead nuclei together at nearly the speed of light, not to create precious metals, but to study how matter behaves under extraordinary energy and temperature, according to Ulrik Egede, a Professor of Physics at Monash University, writing for The Conversation.
In the process, something unexpected happened. When lead nuclei narrowly missed colliding head-on, the immense electromagnetic fields generated between them were strong enough to strip protons from the atomic nucleus. Lead atoms contain three more protons than gold. When exactly three protons were knocked loose, the remaining nucleus effectively became gold.
This transformation required electric fields roughly a million times stronger than those found in natural phenomena like lightning. Such conditions are impossible to produce with conventional chemistry and can only occur in extreme physics experiments.
A man rides his bicycle along the underground Large Hadron Collider during its hiatus in 2020 (AFP via Getty)
The amount of gold created was vanishingly small. Scientists estimate a total of about 29 trillionths of a gram was produced, with roughly 89,000 gold nuclei forming each second during active collisions. Alongside gold, the process also generated traces of thallium and mercury when one or two protons were removed instead.
The gold nuclei themselves could not be directly observed. Instead, researchers detected the stripped protons using specialized instruments known as zero-degree calorimeters, allowing them to infer the formation of new elements indirectly.
Ironically, this modern form of alchemy is more of a problem than a prize. Once a lead nucleus loses protons, it can no longer maintain its precise trajectory within the collider and quickly crashes into the beam pipe walls. This weakens the particle beam and complicates long-term experiments.
Despite the nuisance, the discovery is scientifically valuable. Understanding how and why these transformations occur helps physicists interpret experimental data more accurately and design future high-energy colliders capable of probing even deeper into the fundamental nature of matter.