Experts flag caveats in Marathon Fusion's mercury-to-gold claim

San Francisco-based Marathon Fusion said on October 21 that it had converted mercury into gold in a September experiment, at a rate ten times a 2025 CERN record. It proposes exposing mercury-198 to fusion neutrons to make mercury-197, which decays into gold. An analysis lists seven caveats, calling the claims unverified and large-scale production infeasible.