The ALICE Collaboration is a winner of the 2025 Gizmodo Science Fair for transforming lead into gold for a fraction of a second and exposing the strange physics that goes on inside the Large Hadron Collider.
The question
What byproducts does ALICE—the Large Ion Collider Experiment at CERN—produce when it studies matter at extreme energy levels?
The result
Many different things, but perhaps most interesting of all—gold!
In a Physical Review C paper published earlier this year, the ALICE Collaboration announced that between 2015 and 2018, the Large Hadron Collider (LHC) created around 86 billion gold nuclei, each lasting for about a microsecond.
ALICE primarily studies high-energy collisions between lead nuclei, whose charge is 82 times that of a proton. These large nuclei travel nearly at the speed of light in the Large Hadron Collider, which slams these particles into the ALICE detector. These collisions produce a pulse of photon energy that chips away bits of the nuclei—usually neutrons, but sometimes protons. When a lead nucleus loses three protons, it transmutes into element number 79, or gold.
This transmutation occurs around 50,000 to 80,000 times per second. Indeed, the program’s “gold production is quite copious,” said John Jowett, an accelerator physicist at CERN. “However, on a human scale the gold production is very small. [Until] now we’ve only created about, I think, 90 picograms, which is one millionth of a gram of gold.”
Those 90 picograms of gold disappear almost immediately after emerging, he added. “So this just reminds us—I like to say to people—how small atoms are compared to the scales we’re used to,” he said.
Why they did it
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